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In breeding programs, stress memory in plants can develop drought stress tolerance. Memory stress, as an approach, can keep stress data by activating tolerance mechanisms. This research was conducted to evaluate some physiologically effective mechanisms in inducing memory drought stress in the seeds that were exposed to water stress three times in four treatments including rainfed, 33%, 66%, and 100% of field capacity (FC). After the production of the seeds, the third-generation seeds were placed under different irrigation treatments, seed and seedling traits, starch to carbohydrate ratio in seed, protein concentration and glutathione reductase were investigatied in a factorial format based on a randomized complete block design with three replications. Results showed that percentage of changes from the lowest to the highest value for traits including seed vigor, seed endosperm weight, seed coat weight, accelerated aging, cold test, seedling biomass and seedling length were 25, 37, 65, 65, 55, 77, 55, 65 and 79, respectively and germination uniformity was 3.9 times higher than the lowest amount. According to the deterioration percentage, seed vigor and the percentage of seed germination in cold test data, it can be reported that seed production by 100% FC was not appropriate for rainfed plots. However, considering the the appropriate results in the percentage of germination for a cold test, germination uniformity percentage, and the lowest accelerated aging seeds, seed production under the rainfed conditions with 33% FC watering can be recommended. In-silico analysis was coducted on Glutathione reductase (GR) enzymes in Gossypium hirsutum. It is clear that GR has a Redox-active site and NADPH binding, and it interacts with Glutathione S transferase (GST). So, memory drought stress through inducing physiological drought tolerance mechanisms such as starch-to-carbohydrate ratio and GR can determine the suitable pattern for seed production for rainfed and low rainfall regions in a breeding program. Our study thus illustrated that seed reprduction under 33% FC equipped cotton with the tolerance against under draught stress from the seedling stage. This process is done through activating glutathione reductase and balancing the ratio of starch to carbohydrates concentration., (© 2024. The Author(s).)

Backround: In recent years, with the increasing demand for seedless grape varieties that have lower production costs, are disease resistant/tolerant and require less chemical pesticides, the embryo recovery technique has begun to be used more in table grape breeding studies. However, the desired high success rate has not yet been achieved in these studies. Although there are different reasons for this, especially the grape varieties selected for cross-breeding and the timing of transferring the embryos to medium are among the most important reasons. In this study, focusing on these two important factors, the embryos obtained from different hybridization combinations were transferred to agar medium at different weeks for 4 years and the most successful combination and time were determined. In addition, seedless and large berry grape varieties and some seeded varieties that are resistant/tolerant to fungal diseases were selected as parents because they can provide resistance to disease infections in vitro and thus increase the success rate., Results: The results obtained from the study showed that the selected variety and combination significantly affected the success rate in embryo rescue. Especially in combinations with the 'Yalova Seedless' variety as the female parent, more successful results were obtained compared to combinations of other varieties. When 'Yalova Seedless' variety was pollinated with pollen of 'Red Globe', 'Muscat Bailey A' and 'Exalta' varieties, more seedlings were obtained with the help of embryo rescue. The results obtained over four years showed that the best sampling time after pollination was the eighth week and then the seventh week., Conclusions: According to the results obtained, it has been shown that the selected varieties and the sampling time significantly affect the success rate in embryo rescue studies. Therefore, higher success rates can be achieved in comprehensive breeding studies in which they will be included as pollinators, especially in different seeded varieties that are resistant to diseases and have larger berry size., (© 2024. The Author(s).)

In plant tissue culture, differences in endogenous levels of species-specific plant growth regulators (PGRs) may explain differences in regenerative capacity. In the case of polyamines (PAs), their dynamics and distribution may vary between species, genotypes, tissues, and developmental pathways, such as sexual reproduction and apomixis. In this study, for the first time, we aimed to assess the impact of varying endogenous PAs levels in seeds from distinct reproductive modes in Miconia spp. (Melastomataceae), on their in vitro regenerative capacity. We quantified the free PAs endogenous content in seeds of Miconia australis (obligate apomictic), Miconia hyemalis (facultative apomictic), and Miconia sellowiana (sexual) and evaluated their in vitro regenerative potential in WPM culture medium supplemented with a combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). The morphogenic responses were characterized by light microscopy and scanning electron microscopy and discussed regarding the endogenous PAs profiles found. Seeds of M. sellowiana presented approximately eight times more putrescine than M. australis, which was associated with a higher percentage of regenerated calluses (76.67%) than M. australis (5.56%). On the other hand, spermine levels were significantly higher in M. australis. Spermine is indicated as an inhibitor of auxin-carrying gene expression, which may have contributed to its lower regenerative capacity under the tested conditions. These findings provide important insights into in vitro morphogenesis mechanisms in Miconia and highlight the significance of endogenous PA levels in plant regeneration. These discoveries can potentially optimize future regeneration protocols in Miconia, a plant group still underexplored in this area., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

In the realm of plant biology and agriculture, seed germination serves as a fundamental process with far-reaching implications for crop production and environmental health. This comprehensive review seeks to unravel the intricate web of interactions between some biotic stressors and seed germination, addressing the pertinent issue of how these stressors influence seed germination. Different chemicals produced by interacting plants (different parts), fungi, bacteria, or insects can either promote or inhibit seed germination. Releasing chemicals that modulate signaling pathways and cellular processes significantly disrupt essential cellular functions. This disruption leads to diverse germination outcomes, introducing additional layers of complexity to this regulatory landscape. The chemicals perturb enzyme activity and membrane integrity, imposing unique challenges on the germination process. Understanding the mechanisms- how allelochemicals, mycotoxins, or bacterial toxins affect seed germination or the modes of action holds promise for more sustainable agricultural practices, enhanced pest control, and improved environmental outcomes. In sum, this review contributes to a fundamental exposition of the pivotal role of biotic stressors in shaping the germination of seeds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Understanding the reproductive biology of weeds is crucial for managing them effectively. Diplachne fusca (Poaceae) is a widely distributed weed species that poses significant challenges to agricultural productivity. Nevertheless, it remains unclear how the soil seed bank of D. fusca responds to environmental shifts, and whether a dormancy cycle is present in this species., Methods: We investigated how seed dormancy in D. fusca is broken and how it responds to natural environmental changes. The impact of incubation temperature, light exposure, cold stratification at 4 °C, and gibberellic acid (GA 3 ) on seed germination/dormancy-break was investigated, along with assessing seasonal changes in germinability through monthly excavation and laboratory incubation of buried seeds over 2 years., Results: Results indicated that newly ripened seeds of D. fusca were dormant, with germination facilitated by GA 3 , cold stratification, and after-ripening at ambient room conditions. Exposure to darkness inhibited germination. Seasonal patterns of germination were observed, with peak germination occurring in cooler months and a marked decline during the hot summer months. After 2 years of being buried, approximately 40% of the seeds remained viable., Conclusion: In summary, seeds of D. fusca exhibit non-deep physiological dormancy and maintain a persistent soil seed bank. Seeds buried in the soil undergo a yearly dormancy/non-dormancy cycle. This dormancy cycle prevents seed germination and seedling emergence in autumn, which boosts the survival of seedlings in less favorable seasons, yet it also makes it more challenging to eradicate this weed., Competing Interests: Shuai Gong and Wenya Hao are employed by Sinochem Agriculture Holdings Co. Ltd., (© 2024 Song et al.)

Climate change has become a concern, emphasizing the need for the development of crops tolerant to drought. Therefore, this study is designed to explore the physiological characteristics of quinoa that enable it to thrive under drought and other extreme stress conditions by investigating the combined effects of irrigation water levels (100%, 75%, and 50% of quinoa's water requirements, WR as I1, I2 and I3) and different planting methods (basin, on-ridge, and in-furrow as P1, P2 and P3) on quinoa's physiological traits and gas exchange. Results showed that quinoa's yield is lowest with on-ridge planting and highest in the in-furrow planting method. Notably, the seed protein concentrations in I2 and I3 did not significantly differ but they were 25% higher than those obtained in I1, which highlighted the possibility of using a more effective irrigation method without compromising the seed quality. On the other hand, protein yield (PY) was lowest in P2 (mean of I1 and I2 as 257 kg ha -1 ) and highest in P3 (mean of I1 and I2 as 394 kg ha -1 , 53% higher). Interestingly, PY values were not significantly different in I1 and I2, but they were lower significantly in I3 by 28%, 27% and 20% in P1, P2, and P3, respectively. Essential plant characteristics including plant height, stem diameter, and panicle number were 6.1-16.7%, 6.4-24.5%, and 18.4-36.5% lower, respectively, in I2 and I3 than those in I1. The highest Leaf Area Index (LAI) value (5.34) was recorded in the in-furrow planting and I1, while the lowest value was observed in the on-ridge planting method and I3 (3.47). In I3, leaf temperature increased by an average of 2.5-3 o C, particularly during the anthesis stage. The results also showed that at a similar leaf water potential (LWP) higher yield and dry matter were obtained in the in-furrow planting compared to those obtained in the basin and on-ridge planting methods. The highest stomatal conductance (gs) value was observed within the in-furrow planting method and full irrigation (I1P3), while the lowest values were obtained in the on-ridge and 50%WR (I3P2). Finally, photosynthesis rate (An) reduction with diminishing LWP was mild, providing insights into quinoa's adaptability to drought. In conclusion, considering the thorough evaluation of all the measured parameters, the study suggests using the in-furrow planting method with a 75%WR as the best approach for growing quinoa in arid and semi-arid regions to enhance production and resource efficiency., (© 2024. The Author(s).)

Self-sustaining vegetation in metal-contaminated areas is essential for rebuilding ecological resilience and community stability in degraded lands. Metal-tolerant plants originating from contaminated post-mining areas may hold the key to successful plant establishment and growth. Yet, little is known about the impact of metal toxicity on reproductive strategies, metal accumulation, and allocation patterns at the seed stage. Our research focused on the metal tolerant Atriplex lentiformis. Specifically, we examined the effects of toxic metal(loid) concentration in soils on variability in its reproductive strategies, including germination patterns, elemental uptake, and allocation within the seeds. We employed advanced imaging techniques like synchrotron X-ray fluorescence microscopy (2D scans and 3D tomograms) combined with inductively coupled plasma mass spectrometry to reveal significant differences in metal(loid) concentration and distribution within the seed structures of A. lentiformis from contrasting habitats. Exclusive Zn hotspots of high concentrations were found in the seeds of the metallicolous accession, primarily in the sensitive tissues of shoot apical meristems and root zones of the seed embryos. Our findings offer novel insights into phenotypic variability and metal tolerance and accumulation in plants from extreme environments. This knowledge can be applied to enhance plant survival and performance in land restoration efforts., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background and Aims: Some plants germinate their seeds enclosed by a pericarp, whereas others lack the outer packaging. As a maternal tissue, the pericarp might impart seeds with different germination strategies. Plants in a community with different flowering times might separately disperse and germinate their seeds; therefore, flowering time can be considered as one manifestation of maternal effects on the offspring. The mass of the seed is another important factor influencing germination and represents the intrinsic resource of the seed that supports germination. Using seeds from a species-rich alpine meadow located in the Hengduan Mountains of China, a global biodiversity hotspot, we aimed to illustrate whether and how the type of seed (with or without a pericarp) modulates the interaction of flowering time and seed mass with germination., Methods: Seeds were germinated in generally favourable conditions, and the speed of germination [estimated by mean germination time (MGT)] was calculated. We quantified the maternal conditions by separation of flowering time for 67 species in the meadow, of which 31 produced seeds with pericarps and 36 yielded seeds without pericarps. We also weighed 100 seeds of each species to assess their mass., Key Results: The MGT varied between the two types of seeds. For seeds with pericarps, MGT was associated with flowering time but not with seed mass. Plants with earlier flowering times in the meadow exhibited more rapid seed germination. For seeds without a pericarp, the MGT depended on seed mass, with smaller seeds germinating more rapidly than larger seeds., Conclusions: The distinct responses of germination to flowering time and seed mass observed in seeds with and without a pericarp suggest that germination strategies might be mother-reliant for seeds protected by pericarps but self-reliant for those without such protection. This new finding improves our understanding of seed germination by integrating ecologically mediated maternal conditions and inherent genetic properties., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Nicosulfuron-resistant biotype (R) and -sensitive biotype (S) Amaranthus retroflexus L. seeds were subjected to different temperature, light, salt, osmotic potential, pH value and burial depth treatments. The difference in germination response of two populations to the above abiotic environmental factors was used to study the fitness cost of nicosulfuron-resistance evolution in A. retroflexus. The aim is to find a powerful tool for weed control in the presence of evolutionary resistance selection. The results of this experiment showed that the germination rate and germination index in S population were generally higher than that in R population. When the salt stress was 80 mM, the water potential was -0.1 Mpa ~ -0.4 Mpa, and under strong acid and alkali conditions, the germination index in S population was prominently higher than that in R population (p<0.05). The delayed seed germination in R population indicated that its nicosulfuron resistance may be linked to seed biochemical compositions that altered seed germination dynamics. The resistant and sensitive biotype of A. retroflexus had differently favourable adaptability in diverse environments. Salt, osmotic potential and pH value are not the major constraints for A. retroflexus germination, however, A. retroflexus are strongly responsive to temperature, light and burial depth. Considering that seeds of A. retroflexus are unable to reach the soil surface beyond the depth of 6 cm, deep inversion tillage before sowing may be an effective and economical weed management tool for the control of nicosulfuron resistant A. retroflexus., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Constant-frequency ultrasonic treatment helped to improve seed germination. However, variable-frequency ultrasonic treatment on maize seed germination were rarely reported. In this study, maize seeds were exposed to 20-40 kHz ultrasonic for 40 s. The germination percentage and radicle length of maize seeds increased by 10.4% and 230.5%. Ultrasonic treatment also significantly increased the acid protease, α-amylase, and β-amylase contents by 96.4%, 73.8%, and 49.1%, respectively. Transcriptome analysis showed that 11,475 differentially expressed genes (DEGs) were found in the ultrasonic treatment and control groups, including 5,695 upregulated and 5,780 downregulated. Metabolic pathways and transcription factors (TFs) were significantly enriched among DEGs after ultrasonic treatment. This included metabolism and genetic information processing, that is, ribosome, proteasome, and pyruvate metabolism, sesquiterpenoid, triterpenoid, and phenylpropanoid biosynthesis, and oxidative phosphorylation, as well as transcription factors in the NAC, MYB, bHLH, WRKY, AP2, bZIP, and ARF families. Variable-frequency ultrasonic treatment increased auxin, gibberellin, and salicylic acid by 5.5%, 37.3%, and 28.9%, respectively. Abscisic acid significantly decreased by 33.2%. The related DEGs were upregulated and downregulated to varying degrees. Seed germination under the abiotic stress conditions of salt stress (NaCl solution), drought (PEG solution), and waterlogging (water-saturated sand bed) under ultrasonic treatment were promoted, radicle length was significantly increased by 30.2%, 30.5%, and 27.3%, respectively; and germination percentage by 14.8%, 20.1%, and 21.6%, respectively. These findings provide new insight into the mechanisms through ultrasonic to promote maize seed germination., (© 2024. The Author(s).)

In many regions, the climate is changing faster during winter than during the other seasons, and a loss of snow cover combined with increased temperature variability can expose overwintering organisms to harmful conditions. Understanding how species respond to these changes during critical developmental times, such as seed germination, helps us assess the ecological implications of winter climate change. To address this concern, we measured the breaking of seed dormancy and cold tolerance of temperate grassland species in the lab and field. In the lab, we ran germination trials testing the tolerance of 17 species to an extreme cold event. In the field, we deployed seeds of two species within a snow manipulation experiment at three locations and measured germination success biweekly from seeds subjected to ambient and reduced snow cover from winter into spring. From lab trials, cold tolerance varied among species, with seed germination decreasing <10%-100% following extreme cold events. Cold tolerance was related to seed traits, specifically less round seeds, seeds that required cold stratification, and seeds that mature later in the season tended to be more impacted by extreme cold temperatures. This variation in seed cold tolerance may contribute to altered community composition with continued winter climate change. In the field, germination increased through late winter, coinciding with the accumulation of days where temperatures were favorable for cold stratification. Through spring, germination success decreased as warm temperatures accumulated. Collectively, species-specific seed cold tolerances and mortality rates may contribute to compositional changes in grasslands under continued winter climate change., (© 2024 The Ecological Society of America.)

Global forests are increasingly lost to climate change, disturbance, and human management. Evaluating forests' capacities to regenerate and colonize new habitats has to start with the seed production of individual trees and how it depends on nutrient access. Studies on the linkage between reproduction and foliar nutrients are limited to a few locations and few species, due to the large investment needed for field measurements on both variables. We synthesized tree fecundity estimates from the Masting Inference and Forecasting (MASTIF) network with foliar nutrient concentrations from hyperspectral remote sensing at the National Ecological Observatory Network (NEON) across the contiguous United States. We evaluated the relationships between seed production and foliar nutrients for 56,544 tree-years from 26 species at individual and community scales. We found a prevalent association between high foliar phosphorous (P) concentration and low individual seed production (ISP) across the continent. Within-species coefficients to nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) are related to species differences in nutrient demand, with distinct biogeographic patterns. Community seed production (CSP) decreased four orders of magnitude from the lowest to the highest foliar P. This first continental-scale study sheds light on the relationship between seed production and foliar nutrients, highlighting the potential of using combined Light Detection And Ranging (LiDAR) and hyperspectral remote sensing to evaluate forest regeneration. The fact that both ISP and CSP decline in the presence of high foliar P levels has immediate application in improving forest demographic and regeneration models by providing more realistic nutrient effects at multiple scales., (© 2024 The Author(s). Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

Increased temperature can induce plastic changes in many plant traits. However, little is known about how these changes affect plant interactions with insect pollinators and herbivores, and what the consequences for plant fitness and selection are. We grew fast-cycling Brassica rapa plants at two temperatures (ambient and increased temperature) and phenotyped them (floral traits, scent, colour and glucosinolates). We then exposed plants to both pollinators (Bombus terrestris) and pollinating herbivores (Pieris rapae). We measured flower visitation, oviposition of P. rapae, herbivore development and seed output. Plants in the hot environment produced more but smaller flowers, with lower UV reflectance and emitted a different volatile blend with overall lower volatile emission. Moreover, these plants received fewer first-choice visits by bumblebees and butterflies, and fewer flower visits by butterflies. Seed production was lower in hot environment plants, both because of a reduction in flower fertility due to temperature and because of the reduced visitation of pollinators. The selection on plant traits changed in strength and direction between temperatures. Our study highlights an important mechanism by which global warming can change plant-pollinator interactions and negatively impact plant fitness, as well as potentially alter plant evolution through changes in phenotypic selection., (© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)

Waterlogging stress (WS) hinders kernel development and directly reduces peanut yield; however, the mechanism of kernel filling in response to WS remains unknown. The waterlogging-sensitive variety Huayu 39 was subjected to WS for 3 days at 7 days after the gynophores touched the ground (DAG). We found that WS affected kernel filling at 14, 21, and 28 DAG. WS decreased the average filling rate and kernel dry weight, while transcriptome sequencing and widely targeted metabolomic analysis revealed that WS inhibited the gene expression in starch and sucrose metabolism, which reduced sucrose input and transformation ability. Additionally, genes related to ethylene and melatonin synthesis and the accumulation of tryptophan and methionine were upregulated in response to WS. WS upregulated the expression of the gene encoding tryptophan decarboxylase (AhTDC), and overexpression of AhTDC in Arabidopsis significantly reduced the seed length, width, and weight. Therefore, WS reduced the kernel-filling rate, leading to a reduction in the 100-kernel weight. This survey informs the development of measures that alleviate the negative impact of WS on peanut yield and quality and provides a basis for exploring high-yield and high-quality cultivation, molecular-assisted breeding, and waterlogging prevention in peanut farming., (© 2024 John Wiley & Sons Ltd.)

Despite the considerable efforts reported so far to enhance seed priming, novel ideas are still needed to be suggested to this sustainable sector of agri-seed industry. This could be the first study addressing the effect of nitric oxide (NO) under open field conditions. The impacts of seed redox-priming using sodium nitroprusside (SNP) and osmo-priming with calcium chloride (CaCl 2 ), both applied individually or successively, were investigated under salinity stress conditions on wheat plants (Triticum aestivum L.). Various parameters, including water relations, growth, yield, photosynthetic pigments, and antioxidant activities (enzymatic and non-enzymatic), were recorded to assess the outcomes of these priming agents on mitigating the negative impacts of salinity stress on wheat plants. Water consumptive use (ETa) and irrigation water applied (IWA) decreased with seeds priming. Successive priming with SNP + CaCl 2 induced the greatest values of crop water productivity (CWP), irrigation water productivity (IWP), seed index, grain yield and grain nitrogen content.Under salinity stress, the dry weight of plants was decreased. However, hydro-priming and successive chemical priming agents using combinations of calcium chloride and sodium nitroprusside (CaCl 2  + SNP & SNP + CaCl 2 ) preserved growth under salinity stress.Individual priming with sodium nitroprusside (SNP) and calcium chloride (CaCl 2 ) resulted in the lowest recorded content of sodium in the shoot, with a value of 2 ppm. On the other hand, successive priming using CaCl 2  + SNP or SNP + CaCl 2 induced the contents of potassium in the shoot, with values of 40 ppm and 39 ppm, respectively. Malondialdehyde decreased in shoot significantly withapplicationof priming agents. Successive priming with CaCl 2  + SNP induced the highest proline contents in shoot (6 µg/ g FW). The highest value of phenolics and total antioxidants contents in shoot were recorded under successive priming using CaCl 2  + SNP and SNP + CaCl 2 .Priming agents improved the activities of ascorbate peroxidase and catalase enzymes. The successive priming improved water relations (ETa, IWA, CWP and IWP) and wheat growth and productivity under salinity stress more than individual priming treatments., (© 2024. The Author(s).)

Seed germination is a critical checkpoint for plant growth under unfavorable environmental conditions. In Arabidopsis (Arabidopsis thaliana), the abscisic acid (ABA) and gibberellic acid (GA) signaling pathways play important roles in modulating seed germination. However, the molecular links between salinity stress and ABA/GA signaling are not well understood. Herein, we showed that the expression of DIVARICATA1 (DIV1), which encodes a MYB-like transcription factor, was induced by GA and repressed by ABA, salinity, and osmotic stress in germinating seeds. DIV1 positively regulated seed germination in response to salinity stress by directly regulating the expression of DELAY OF GERMINATION 1-LIKE 3 (DOGL3) and GA-STIMULATED ARABIDOPSIS 4 (GASA4) and indirectly regulating the expression of several germination-associated genes. Moreover, NUCLEAR FACTOR-YC9 (NF-YC9) directly repressed the expression of DIV1 in germinating seeds in response to salinity stress. These results help reveal the function of the NF-YC9-DIV1 module and provide insights into the regulation of ABA and GA signaling in response to salinity stress during seed germination in Arabidopsis., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Competing Interests: Conflict of interest statement. None declared.

Background: Natural populations of Arabidopsis thaliana exhibit phenotypic variations in specific environments and growth conditions. However, this variation has not been explored after seed osmopriming treatments. The natural variation in biomass production and root system architecture (RSA) was investigated across the Arabidopsis thaliana core collection in response to the pre-sawing seed treatments by osmopriming, with and without melatonin (Mel). The goal was to identify and characterize physiologically contrasting ecotypes., Results: Variability in RSA parameters in response to PEG-6000 seed osmopriming with and without Mel was observed across Arabidopsis thaliana ecotypes with especially positive impact of Mel addition under both control and 100 mM NaCl stress conditions. Two ecotypes, Can-0 and Kn-0, exhibited contrasted root phenotypes: seed osmopriming with and without Mel reduced the root growth of Can-0 plants while enhancing it in Kn-0 ones under both control and salt stress conditions. To understand the stress responses in these two ecotypes, main stress markers as well as physiological analyses were assessed in shoots and roots. Although the effect of Mel addition was evident in both ecotypes, its protective effect was more pronounced in Kn-0. Antioxidant enzymes were induced by osmopriming with Mel in both ecotypes, but Kn-0 was characterized by a higher responsiveness, especially in the activities of peroxidases in roots. Kn-0 plants experienced lower oxidative stress, and salt-induced ROS accumulation was reduced by osmopriming with Mel. In contrast, Can-0 exhibited lower enzyme activities but the accumulation of proline in its organs was particularly high. In both ecotypes, a greater response of antioxidant enzymes and proline accumulation was observed compared to mechanisms involving the reduction of Na + content and prevention of K + efflux., Conclusions: In contrast to Can-0, Kn-0 plants grown from seeds osmoprimed with and without Mel displayed a lower root sensitivity to NaCl-induced oxidative stress. The opposite root growth patterns, enhanced by osmopriming treatments might result from different protective mechanisms employed by these two ecotypes which in turn result from adaptive strategies proper to specific habitats from which Can-0 and Kn-0 originate. The isolation of contrasting phenotypes paves the way for the identification of genetic factors affecting osmopriming efficiency., (© 2024. The Author(s).)

As crucial stages in the plant ontogeny, germination and seedling establishment under adverse conditions greatly determine staple crop growth and productivity. In the context of green technologies aiming to improve crop yield, seed priming is emerging as an effective approach to enhance seed vigor and germination performance under salt stress. In this study, we assess the efficiency of seed priming with indole-3-acetic acid (IAA) in mitigating the adverse effects of salt stress on maize (Zea mays L.) seedlings during germination and early seedling stages. In unprimed seeds, salt stress reduced germination indices, and seedling (both radicle and coleoptile) growth, together with decreased tissue hydration. However, seed priming using IAA significantly improved maize salt response, as reflected by the increased seed germination dynamics, early seedling establishment, and water status. Besides, seedlings from IAA-primed seeds showed a higher activity of α-amylase, resulting in increased sugar contents in roots and coleoptiles of salt-stressed plants. Further, IAA-seed priming stimulated the accumulation of endogenous IAA in salt-stressed seedlings, in concomitance with a significant effect on reactive oxygen species detoxification and lipid peroxidation prevention. Indeed, our data revealed increased antioxidant enzyme activities, differentially regulated in roots and coleoptiles, leading to increased activities of the antioxidant enzymes (SOD, CAT and GPX). In summary, data gained from this study further highlight the potential of IAA in modulating early interactions between multiple signaling pathways in the seed, endowing maize seedlings with enhanced potential and sustained tolerance to subsequent salt stress., (© 2024. The Author(s).)

To improve the accuracy of the Hami melon discrete element model, the parameters of the Hami melon seed discrete element model were calibrated by combining practical experiments and simulation tests. The basic physical parameters of Hami melon seeds were obtained through physical experiments, including triaxial size, 100-grain mass, moisture content, density, Poisson's ratio, Young's modulus, shear modulus, angle of repose, suspension speed and various contact parameters. Taking the repose angle of seed simulation as an index, the parameters of each simulation model were significantly screened by the Plackett-Burman test. The results showed that the recovery coefficient, static friction coefficient and rolling friction coefficient of Hami melon seeds had significant effects on repose angle. Based on the steepest climbing test and quadratic regression orthogonal rotation combination test, it was determined that the significant order of the influence of various contact parameters on the angle of repose was static friction coefficient, collision recovery coefficient, and rolling friction coefficient. The optimal parameter combination was obtained through the mathematical regression model between the angle of repose and various contact parameters, namely, the collision recovery coefficient of Hami melon seeds was 0.518, the static friction coefficient of Hami melon seeds was 0.585 and the rolling friction coefficient of Hami melon seeds was 0.337. Under this condition, three static seed-dropping experiments and dynamic rolling accumulation experiments were carried out. The average simulated angle of repose was 31.93°, and the relative error with the actual value was only 1.71%. The average simulated rolling accumulation angle was 51.98°, and the relative error with the actual value was only 1.92%., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Wan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Water deficiency stress reduces yield in grain legumes, primarily due to a decrease in the pods number. Melatonin (ML) and 24-epibrassinolide (EBL) are recognized for their hormone-like properties that improve plant tolerance to abiotic stresses. This study aimed to assess the impact of different concentrations of ML (0, 100, and 200 µM) and EBL (0, 3, and 6 µM) on the growth, biochemical, and physiological characteristics of chickpea plants under water-stressed conditions., Results: The study's findings indicated that under water-stressed conditions, a decrease in seed (30%) and pod numbers (31%), 100-seed weight (17%), total chlorophyll content (46%), stomatal conductance (33%), as well as an increase in H 2 O 2 (62%), malondialdehyde content (40%), and electrolyte leakage index (40%), resulted in a 40% reduction in chickpea plants grain yield. Our findings confirmed that under water-stressed conditions, seed oil, seed oil yield, and seed protein yield dropped by 20%, 55%, and 36%, respectively. The concurrent exogenous application of ML and EBL significantly reduces oxidative stress, plasma membrane damage, and reactive oxygen species (ROS) content. This treatment also leads to increased yield and its components, higher pigment content, enhanced oil and protein yield, and improved enzymatic and non-enzymatic antioxidant activities such as catalase, superoxide dismutase, polyphenol oxidase, ascorbate peroxidase, guaiacol peroxidase, flavonoid, and carotenoid. Furthermore, it promotes the accumulation of osmoprotectants such as proline, total soluble protein, and sugars., Conclusions: Our study found that ML and EBL act synergistically to regulate plant growth, photosynthesis, osmoprotectants accumulation, antioxidant defense systems, and maintain ROS homeostasis, thereby mitigating the adverse effects of water deficit conditions. ML and EBL are key regulatory network components in stressful conditions, with significant potential for future research and practical applications. The regulation metabolic pathways of ML and EBL in water-stressed remains unknown. As a result, future research should aim to elucidate the molecular mechanisms by employing genome editing, RNA sequencing, microarray, transcriptomic, proteomic, and metabolomic analyses to identify the mechanisms involved in plant responses to exogenous ML and EBL under water deficit conditions. Furthermore, the economical applications of synthetic ML and EBL could be an interesting strategy for improving plant tolerance., (© 2024. The Author(s).)

Rapid elongation of coleoptiles from rice seeds to reach the water surface enables plants to survive submergence stress and therefore plays a crucial role in allowing direct seeding in rice cultivation. Gibberellin (GA) positively influences growth in rice, but the molecular mechanisms underlying its regulation of coleoptile elongation under submerged conditions remain unclear. In this study, we performed a weighted gene co-expression network analysis to conduct a preliminarily examination of the mechanisms. Four key modules were identified with high correlations to the GA regulation of submergence tolerance. The genes within these modules were mainly involved in the Golgi apparatus and carbohydrate metabolic pathways, suggesting their involvement in enhancing submergence tolerance. Further analysis of natural variation revealed that the specific hub genes Os03g0337900, Os03g0355600, and Os07g0638400 exhibited strong correlations with subspecies divergence of the coleoptile elongation phenotype. Consistent with this analysis, mutation of Os07g0638400 resulted in a lower germination potential and a stronger inhibition of coleoptile elongation under submerged conditions. The hub genes identified in this study provide new insights into the molecular mechanisms underlying GA-dependent tolerance to submergence stress in rice, and a potential basis for future modification of rice germplasm to allow for direct seeding., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

ABSCISIC ACID INSENSITIVE5 (ABI5), a key regulator of the abscisic acid (ABA) signalling pathway, plays a fundamental role in seed germination and post-germinative development. However, the molecular mechanism underlying the repression function of ABI5 remains to be elucidated. In this study, we demonstrate that the conserved eukaryotic WD40 repeat protein Receptor for Activated C Kinase 1 (RACK1) is a novel negative regulator of ABI5 in Arabidopsis. The RACK1 loss-of-function mutant is hypersensitive to ABA, while this phenotype is rescued by a mutation in ABI5. Moreover, overexpression of RACK1 suppresses ABI5 transcriptional activation activity for ABI5-targeted genes. RACK1 may also physically interact with ABI5 and facilitate its degradation. Furthermore, we found that RACK1 and the two substrate receptors CUL4-based E3 ligases (DWA1 and DWA2) function together to mediate the turnover of ABI5, thereby efficiently reducing ABA signalling in seed germination and post-germinative growth. In addition, molecular analyses demonstrated that ABI5 may bind to the promoter of RACK1 to repress its expression. Collectively, our findings suggest that RACK1 and ABI5 might form a feedback loop to regulate the homeostasis of ABA signalling in acute seed germination and early plant development., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background and Aims: Chinese pistachio (Pistacia chinensis), an important horticultural plant species, holds great ornamental value with beautiful leaves and fruits. Seedling propagation of this tree species is restricted by its erratic seed germination; however, the germination mechanism is ambiguous. The aim of this study was to determine the germination mechanism from a novel perspective based on the multi-omics data., Methods: The multi-omics technique combined with hormone content measurement was applied to seed germination of Chinese pistachio., Key Results: Due to its great accumulation during seed germination, catechin stood out from the identified metabolites in a broadly targeted metabolomic analysis. Exogenous catechin at 10 mg L-1 significantly improved the germination of Chinese pistachio seeds. An interesting result of hormone analysis was that the improving effect of catechin could be attributed to an increase in gibberellic acid 3 (GA3) content rather than a decrease in abscisic acid (ABA) content before germination. Treatments with paclobutrazol (PAC, a GA biosynthesis inhibitor) and PAC + catechin also showed that the promoting effect of catechin on seed germination depends on GA biosynthesis. Transcriptome analysis and qRT‒PCR further revealed that catechin induced the expression of PcGA20ox5 to activate GA biosynthesis. Several transcription factors were induced by catechin and GA treatments, such as TCP, bZIP and C3H, which may play an important regulatory role in GA biosynthesis in a catechin-mediated way., Conclusions: Catechin promotes seed germination via GA biosynthesis in Chinese pistachios. This study proposes a novel mechanism by which catechin promotes seed germination via the GA pathway, which provides new insight into a comprehensive understanding of seed dormancy and germination., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Secondary dormancy is an adaptive trait that increases reproductive success by aligning seed germination with permissive conditions for seedling establishment. Aethionema arabicum is an annual plant and member of the Brassicaceae that grows in environments characterized by hot and dry summers. Aethionema arabicum seeds may germinate in early spring when seedling establishment is permissible. We demonstrate that long-day light regimes induce secondary dormancy in the seeds of Aethionema arabicum (CYP accession), repressing germination in summer when seedling establishment is riskier. Characterization of mutants screened for defective secondary dormancy demonstrated that RGL2 mediates repression of genes involved in gibberellin (GA) signaling. Exposure to high temperature alleviates secondary dormancy, restoring germination potential. These data are consistent with the hypothesis that long-day-induced secondary dormancy and its alleviation by high temperatures may be part of an adaptive response limiting germination to conditions permissive for seedling establishment in spring and autumn., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Plants in habitats with unpredictable conditions often have diversified bet-hedging strategies that ensure fitness over a wider range of variable environmental factors. A striking example is the diaspore (seed and fruit) heteromorphism that evolved to maximize species survival in Aethionema arabicum (Brassicaceae) in which external and endogenous triggers allow the production of two distinct diaspores on the same plant. Using this dimorphic diaspore model, we identified contrasting molecular, biophysical, and ecophysiological mechanisms in the germination responses to different temperatures of the mucilaginous seeds (M+ seed morphs), the dispersed indehiscent fruits (IND fruit morphs), and the bare non-mucilaginous M- seeds obtained by pericarp (fruit coat) removal from IND fruits. Large-scale comparative transcriptome and hormone analyses of M+ seeds, IND fruits, and M- seeds provided comprehensive datasets for their distinct thermal responses. Morph-specific differences in co-expressed gene modules in seeds, as well as in seed and pericarp hormone contents, identified a role of the IND pericarp in imposing coat dormancy by generating hypoxia affecting abscisic acid (ABA) sensitivity. This involved expression of morph-specific transcription factors, hypoxia response, and cell wall remodeling genes, as well as altered ABA metabolism, transport, and signaling. Parental temperature affected ABA contents and ABA-related gene expression and altered IND pericarp biomechanical properties. Elucidating the molecular framework underlying the diaspore heteromorphism can provide insight into developmental responses to globally changing temperatures., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Seed germination and dormancy represent critical phases in the life cycle of plants, tightly regulated by endogenous phytochrome levels and environment signals. High temperatures (HT) induce the overaccumulation of reactive oxygen species (ROS) and increase abscisic acid (ABA), thereby inhibiting seed germination. Our previous findings showed that HT induced the burst of reactive nitrogen species (RNS), increasing the S-nitrosylation modification of HFR1, which effectively blocks seed germination. Importantly, stabilizing HFR1 has been shown to significantly mitigate the inhibitory effect of HT on seed germination. In this study, we reported that HT increased the protein abundance of ABI4, a crucial component in ABA signaling, which in turn activates the expression of RbohD while suppressing the expression of VTC2. This leads to the rapid generation of ROS, thereby inhibiting seed germination. Consistently, the seed germination of abi4 mutant showed insensitivity to HT with lower ROS level during seed germination, whereas transgenic lines overexpressing ABI4 showed reduced germination rates accompanied by elevated ROS levels. Furthermore, we noted that HFR1 interacts with ABI4 to sequester its activity under normal conditions. However, HT-induced ROS triggered the degradation of HFR1, consequently releasing ABI4 activity. This activation of ABI4 promotes RbohD expression, culminating in a ROS burst that suppresses seed germination. Thus, our study unveils a novel function for ABI4 in regulating ROS level and seed germination under HT stress. Throughout this process, HFR1 plays a critical role in restraining ABI4 activity to maintain an optimal endogenous ROS level, thereby ensuring seed germination under favorable environmental conditions., (© 2024 Scandinavian Plant Physiology Society.)

Spatial synchrony may be tail-dependent, meaning it is stronger for peaks rather than troughs, or vice versa. High interannual variation in seed production in perennial plants, called masting, can be synchronized at subcontinental scales, triggering extensive resource pulses or famines. We used data from 99 populations of European beech (Fagus sylvatica) to examine whether masting synchrony differs between mast peaks and years of seed scarcity. Our results revealed that seed scarcity occurs simultaneously across the majority of the species range, extending to populations separated by distances up to 1800 km. Mast peaks were spatially synchronized at distances up to 1000 km and synchrony was geographically concentrated in northeastern Europe. Extensive synchrony in the masting lower tail means that famines caused by beech seed scarcity are amplified by their extensive spatial synchrony, with diverse consequences for food web functioning and climate change biology., (© 2024 John Wiley & Sons Ltd.)

Flowering plants adjust their reproductive period to maximize the success of the offspring. Monocarpic plants, those with a single reproductive cycle that precedes plant senescence and death, tightly regulate both flowering initiation and flowering cessation. The end of the flowering period involves the arrest of the inflorescence meristem activity, known as proliferative arrest, in what has been interpreted as an evolutionary adaptation to maximize the allocation of resources to seed production and the viability of the progeny. Factors influencing proliferative arrest were described for several monocarpic plant species many decades ago, but only in the last few years studies performed in Arabidopsis have allowed to approach proliferative arrest regulation in a comprehensive manner by studying the physiology, hormone dynamics, and genetic factors involved in its regulation. However, these studies remain restricted to Arabidopsis and there is a need to expand our knowledge to other monocarpic species to propose general mechanisms controlling the process. In this work, we have characterized proliferative arrest in Pisum sativum, trying to parallel available studies in Arabidopsis to maximize this comparative framework. We have assessed quantitatively the role of fruits/seeds in the process, the influence of the positional effect of these fruits/seeds in the behavior of the inflorescence meristem, and the transcriptomic changes in the inflorescence associated with the arrested state of the meristem. Our results support a high conservation of the factors triggering arrest in pea and Arabidopsis, but also reveal differences reinforcing the need to perform similar studies in other species., (© 2024 The Author(s). Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.)

Crops generally have seeds larger than their wild progenitors´ and with reduced dormancy. In wild plants, seed mass and allocation to the seed coat (a proxy for physical dormancy) scale allometrically so that larger seeds tend to allocate less to the coats. Larger seeds and lightweight coats might thus have evolved as correlated traits in crops. We tested whether 34 crops and 22 of their wild progenitors fit the allometry described in the literature, which would indicate co-selection of both traits during crop evolution. Deviations from the allometry would suggest that other evolutionary processes contribute to explain the emergence of larger, lightweight-coated seeds in crops. Crops fitted the scaling slope but deviated from its intercept in a consistent way: Seed coats of crops were lighter than expected by their seed size. The wild progenitors of crops displayed the same trend, indicating that deviations cannot be solely attributed to artificial selection during or after domestication. The evolution of seeds with small coats in crops likely resulted from a combination of various pressures, including the selection of wild progenitors with coats smaller than other wild plants, further decreases during early evolution under cultivation, and indirect selection due to the seed coat-seed size allometry., (© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.)

Species functional traits can influence seed dispersal processes and consequently affect species' role in the mutualistic network. Although the effect of animal traits on the structure of the seed dispersal network is well explored, it remains poorly understood how plant and fruit traits contribute to the structure. We here studied the effects of plant and fruit traits on the structure of bird seed dispersal networks across different disturbed habitats in the Meihua Mountain National Nature Reserve, Southeastern China. During the study period, 16, 20, 13, and 15 bird species were recorded foraging on 10, 11, 12, and 8 plant species, resulting in 511, 312, 265, and 201 foraging events in the protected forest, natural forest, village, and bamboo forest, respectively. The composition of these seed dispersal networks is not primarily influenced by a specific group of bulbul species, but rather by the presence of an endangered plant species, Taxus chinensis. As we expected, the structure of the four networks was different among the four disturbed habitats. Furthermore, our results also showed tree height and canopy density were the most important plant traits for structuring the seed dispersal network, while sugar, amylase, dry matter, and alkaloids were identified as significant fruit traits. Overall, our findings highlight the value of integrating trait-based ecology into the framework of the seed dispersal network and provide new insights for mutualistic network conservation in disturbed habitats., (© 2024 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

The protein-repairing enzyme (PRE) PROTEIN L-ISOASPARTYL METHYLTRANSFERASE (PIMT) influences seed vigor by repairing isoaspartyl-mediated protein damage in seeds. However, PIMTs function in other seed traits, and the mechanisms by which PIMT affects such seed traits are still poorly understood. Herein, through molecular, biochemical, and genetic studies using overexpression and RNAi lines in Oryza sativa and Arabidopsis thaliana, we demonstrate that PIMT not only affects seed vigor but also affects seed size and weight by modulating enolase (ENO) activity. We have identified ENO2, a glycolytic enzyme, as a PIMT interacting protein through Y2H cDNA library screening, and this interaction was further validated by BiFC and co-immunoprecipitation assay. We show that mutation or suppression of ENO2 expression results in reduced seed vigor, seed size, and weight. We also proved that ENO2 undergoes isoAsp modification that affects its activity in both in vivo and in vitro conditions. Further, using MS/MS analyses, amino acid residues that undergo isoAsp modification in ENO2 were identified. We also demonstrate that PIMT repairs such isoAsp modification in ENO2 protein, protecting its vital cellular functions during seed maturation and storage, and plays a vital role in regulating seed size, weight, and seed vigor. Taken together, our study identified ENO2 as a novel substrate of PIMT, and both ENO2 and PIMT in turn implicate in agronomically important seed traits., (© 2024 Society for Experimental Biology and John Wiley & Sons Ltd.)

Seed rain and the soil seed bank represent the dispersal of seeds in space and time, respectively, and can be important sources of recruitment of new individuals during plant community regeneration. However, the temporal dynamics of seed rain and the mechanisms by which the seed rain and soil seed bank may play a role in plant community regeneration with increased grazing disturbance remain unclear. Seed rain, soil seed bank, aboveground vegetation, and rodent density were sampled along a grazing gradient in an alpine marsh on the eastern Tibetan Plateau. We described the temporal dynamics of seed dispersal using Bayesian generalized mixed models, and nonmetric multidimensional scaling and the structural equation model were used to examine the effects of grazing disturbance on the relative role of seed rain and soil seed bank on aboveground plant community regeneration. The temporal dynamics of seed rain changed from a unimodal to a bimodal pattern with increased grazing disturbance. Both species diversity and seed density of the seed rain and seed bank increased significantly with increased grazing disturbance. Increased grazing disturbance indirectly increased the similarity of composition between seed rain, seed bank, and aboveground plant community by directly increasing species diversity and abundance of aboveground plant community. However, increased grazing disturbance also indirectly decreased the similarity of seed rain, soil seed bank, and aboveground plant community by directly increasing rodent density. The similarity between seed rain and aboveground plant community was greater than that of the soil seed bank and aboveground plant community with increased grazing disturbance. Grazing disturbance spreads the risk of seed germination and seedling establishment by changing the temporal dynamics of seed dispersal. Plants (positive) and rodents (negative) mediated the role of seed rain and soil seed bank in plant community regeneration. The role of seed rain in plant community regeneration is higher than the seed bank in disturbed alpine marshes. Our findings increase our understanding of the regeneration process of the plant community, and they provide valuable information for the conservation and restoration of alpine marsh ecosystems., (© 2024 The Ecological Society of America.)

Sophora davidii is a cross-pollinated plant with important ecological protection and medicinal value in China, but its seed yield is low due to backward and nonstandard production technology. Therefore, we divide the flowering period of Sophora davidii into initial, full and final flowering period, measuring the floral morphology, pollen viability, stigma receptivity, nectar volume and nectar concentration, foraging behavior of pollinators, fertilization physiology, seed yield and quality through field observation and indoor testing to explore whether the flowering period affects the floral traits, pollinator behavior and seed production of plants. Our results revealed that the nectar volume, nectar concentration, pollen viability and stigma receptivity at full flowering period were the highest. The single visit time and visit time per flower of Chinese honey bees were the longest in the full flowering period, while the number of transfer, visit frequency and number of touching stigma were the least. The visiting number of the bees was the most and the most active in the full flowering period. The bees pollination not only improved the pollen amount, germination rate, pollen tube length and the ovule number of S. davidii , but also their effect was the most obvious in full flowering period. The principal component analysis showed that pollination by Chinese honey bees during the whole flowering period of S. davidii was the best way to produce seeds. We can conclude that flowering period affects flower traits, foraging behavior of pollinators, seed yield and quality of S. davidii .

Pollination is crucial for biodiversity and food security. Heterogeneous agricultural landscapes have a positive effect on pollinator abundance and enhance crop production and quality. In this study, we explored the effects of three landscape features (past crop diversity measured as the Equivalent Richness of crop functional Groups in the previous year [ERGp], semi-natural habitat percentage [SNH], and mean field size [MFS]) and pollinator densities (wild bees [WB] and honey bees [HB]) on pollination and seed quantity and quality in rapeseed crops. Surveying the pollinator density in 20 rapeseed fields revealed a positive relationship with ERGp in the landscape. A pollinator exclusion experiment compared bagged and open-pollinated self-compatible rapeseed plants and revealed insect pollination effectiveness (fruits per flower and number of seeds per pod) and seed quality (oil content). Seed parameters were evaluated in relation to pollinator density (WB-HB) and landscape characteristics. The ERGp emerged as a crucial landscape feature that positively impacted WB density. When insect pollinators were excluded, plants exhibited reduced pollination effectiveness and seed quality. Analysis of open-pollinated plants highlighted ERGp as the most influential variable, positively affecting both sets of parameters. The MFS and SNH showed different but important relationships. Total tocopherol and α-tocopherol were positively correlated with pollinator density in HB, whereas WB showed a positive correlation with γ-tocopherol levels. Increased ERGp positively affected pollinator density and pollination effectiveness, thereby improving oilseed rape production quantity and quality. This study provides new insights into agroecosystem management and pollinator-friendly practices., Competing Interests: Declaration of competing interest The authors declare no competing financial interests or personal relationships that may have influenced the work reported in this study., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Receptor-like kinases (RLKs) constitute a diverse superfamily of proteins pivotal for various plant physiological processes, including responses to pathogens, hormone perception, growth, and development. Their ability to recognize conserved epitopes for general elicitors and specific pathogens marked significant advancements in plant pathology research. Emerging evidence suggests that RLKs and associated components also act as modulators in hormone signaling and cellular trafficking, showcasing their multifunctional roles in growth and development. Notably, STRESS INDUCED FACTOR 2 (SIF2) stands out as a representative with distinct expression patterns in different Arabidopsis organs. Our prior work highlighted the specific induction of SIF2 expression in guard cells, emphasizing its positive contribution to stomatal immunity. Expanding on these findings, our present study delves into the diverse functions of SIF2 expression in root tissues. Utilizing comprehensive physiology, molecular biology, protein biochemistry, and genetic analyses, we reveal that SIF2 modulates abscisic acid (ABA) signaling in Arabidopsis roots. SIF2 is epistatic with key regulators in the ABA signaling pathway, thereby governing the expression of genes crucial for dormancy release and, consequently, Arabidopsis seed germination. This study sheds light on the intricate roles of SIF2 as a multi-functional RLK, underscoring its organ-specific contributions to plant immunity, hormonal regulation, and seed germination., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Abscisic acid (ABA) and gibberellin (GA) are major regulators of seed dormancy, an adaptive trait closely associated with preharvest sprouting. This study examined transcriptional regulation of ABA and GA metabolism genes and modulation of ABA and GA levels in seeds of barley genotypes exhibiting a range of dormancy phenotype. We observed a very strong negative correlation between genetic variation in seed germination and embryonic ABA level (r = 0.85), which is regulated by transcriptional modulation of HvNCED1 and/or HvCYP707A genes. A strong positive correlation was evident between variation in seed germination and GA level (r = 0.64), mediated via transcriptional regulation of GA biosynthesis genes, HvGA20ox2 and/or HvGA3oxs, and GA catabolism genes, HvGA2ox3 and/or HvGA3ox6. Modulation of the ABA and GA levels in the genotypes led to the prevalence of ABA to GA level ratio that exhibited a very strong negative correlation (r = 0.84) with seed germination, highlighting the importance of a shift in ABA/GA ratio in determining genetic variation of dormancy in barley seeds. Our results overall show that transcriptional regulation of specific ABA and GA metabolism genes underlies genetic variation in ABA/GA ratio and seed dormancy, reflecting the potential use of these genes as molecular tools for enhancing preharvest sprouting resistance in barley., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

The decline in seed quality over time due to natural aging or mishandling requires assessing seed vigor for resilience in adverse conditions. Accelerated aging (AA) methods simulate seed deterioration by subjecting seeds to high temperatures and humidity. Saturated salt accelerated aging (SSAA) is an AA method adopted for small seeds like lettuce ( Lactuca sativa ). In this study, we subjected seeds of two lettuce cultivars ('Muir' and 'Bauer') to SSAA by sealing them in a box containing 40 g/100 mL of a sodium chloride (NaCl) solution in a dark growth chamber at 41 °C for 24, 48, and 72 h with a control. We monitored their vigor using embedded computer cameras, tracking the projected canopy size (PCS) daily from sowing to harvest. The cultivar 'Muir' exhibited consistent PCS values across the treatments, while 'Bauer' showed PCS variations, with notable declines after prolonged aging. The germination rates dropped significantly after 48 and 72 h of SSAA. A nonlinear regression model revealed a strong relationship between PCS and shoot dry weight across harvests and cultivars ( R 2 = 0.93, RMSE = 0.15, p < 0.001). The research found that the projected canopy size and shoot dry weight increased over time with significant differences in treatments for the cultivar 'Bauer' but not for 'Muir,' with the canopy size being a strong predictor of dry weight and no significant impact from the SSAA treatments. This study highlights cultivar-specific responses to aging and demonstrates the efficacy of our imaging tool in predicting lettuce dry weight despite treatment variations. Understanding how aging affects different lettuce varieties is crucial for seed management and crop sustainability.

The survival and growth of young plants hinge on various factors, such as seed quality and environmental conditions. Assessing seedling potential/vigor for a robust crop yield is crucial but often resource-intensive. This study explores cost-effective imaging techniques for rapid evaluation of seedling vigor, offering a practical solution to a common problem in agricultural research. In the first phase, nine lettuce ( Lactuca sativa ) cultivars were sown in trays and monitored using chlorophyll fluorescence imaging thrice weekly for two weeks. The second phase involved integrating embedded computers equipped with cameras for phenotyping. These systems captured and analyzed images four times daily, covering the entire growth cycle from seeding to harvest for four specific cultivars. All resulting data were promptly uploaded to the cloud, allowing for remote access and providing real-time information on plant performance. Results consistently showed the 'Muir' cultivar to have a larger canopy size and better germination, though 'Sparx' and 'Crispino' surpassed it in final dry weight. A non-linear model accurately predicted lettuce plant weight using seedling canopy size in the first study. The second study improved prediction accuracy with a sigmoidal growth curve from multiple harvests ( R 2 = 0.88, RMSE = 0.27, p < 0.001). Utilizing embedded computers in controlled environments offers efficient plant monitoring, provided there is a uniform canopy structure and minimal plant overlap.

Drought poses significant risks to maize cultivation by impairing plant growth, water uptake and yield; nano priming offers a promising avenue to mitigate these effects by enhancing plant water relations, stress tolerance and overall productivity. In the current experiment, we tested a hypothesis that seed priming with iron oxide nanoparticles (n-Fe 2 O 3 ) can improve maize performance under water stress by improving its growth, water relations, yield and biochemical attributes. The experiment was conducted on a one main plot bisected into two subplots corresponding to the water and drought environments. Within each subplot, maize plants were raised from n-Fe 2 O 3 primed seeds corresponding to 0 mg. L - 1 (as control treatment), 25, 50, 75, and 100 mg. L - 1 (as trial treatments). Seed priming with n-Fe 2 O 3 at a concentration of 75 mg. L - 1 improved the leaf relative water content, water potential, photosynthetic water use efficiency, and leaf intrinsic water use efficiency of maize plants by 13%, 44%, 64% and 17%, respectively compared to control under drought stress. The same treatments improved plant biochemical attributes such as total chlorophyll content, total flavonoids and ascorbic acid by 37%, 22%, and 36%, respectively. Seed priming with n-Fe 2 O 3 accelerated the functioning of antioxidant enzymes such as SOD and POD and depressed the levels of leaf malondialdehyde and hydrogen peroxide significantly. Seed priming with n-Fe 2 O 3 at a concentration of 75 mg. L - 1 improved cob length, number of kernel rows per cob, and 100 kernel weight by 59%, 27% and 33%, respectively, under drought stress. Seed priming with n-Fe 2 O 3 can be used to increase maize production under limited water scenarios., (© 2024. The Author(s).)

Background and Aims: Seed heteromorphism is a plant strategy that an individual plant produces two or more distinct types of diaspores, which have diverse morphology, dispersal ability, ecological functions and different effects on plant life history traits. The aim of this study was to test the effects of seasonal soil salinity and burial depth on the dynamics of dormancy/germination and persistence/depletion of buried trimorphic diaspores of a desert annual halophyte Atriplex centralasiatica., Methods: We investigated the effects of salinity and seasonal fluctuations of temperature on germination, recovery of germination and mortality of types A, B, C diaspores of A. centralasiatica in the laboratory and buried diaspores in situ at four soil salinities and three depths. Diaspores were collected monthly from the seedbank from December 2016 to November 2018, and the number of viable diaspores remaining (not depleted) and their germinability were determined., Results: Non-dormant type A diaspores were depleted in the low salinity "window" in the first year. Dormant diaspore types B and C germinated to high percentages at 0.3 and 0.1 mol L -1 soil salinity, respectively. High salinity and shallow burial delayed depletion of diaspore types B and C. High salinity delayed depletion time of the three diaspore types and delayed dormancy release of types B and C diaspores from autumn to spring. Soil salinity modified the response of diaspores in the seedbank by delaying seed dormancy release in autum and winter and by providing a low-salt concentration window for germination of non-dormant diaspores in spring and early summer., Conclusions: Buried trimorphic diaspores of annual desert halophyte A. centralasiatica exhibited diverse dormancy/germination behavior in respond to seasonal soil salinity fluctuation. Prolonging persistence of the seedbank and delaying depletion of diaspores under salt stress in situ primarily is due to inhibition of dormancy-break. The differences in dormancy/germination and seed persistence in the soil seedbank may be a bet-hadging strategy adapted to stressful temporal and spatial heterogeneity, and allows A. centralasiatica to persist in the unpredictable cold desert enevironment., (© 2024. The Author(s).)

Early season carrot (Daucus carota) production is being practiced in Punjab, Pakistan to meet the market demand but high temperature hampers the seed germination and seedling establishment which cause marked yield reduction. Seed priming with potassium nitrate breaks the seed dormancy and improves the seed germination and seedling growth potential but effects vary among the species and ecological conditions. The mechanism of KNO 3 priming in high temperature stress tolerance is poorly understood yet. Thus, present study aimed to evaluate high temperature stress tolerance potential of carrot seeds primed with potassium nitrate and impacts on growth, physiological, and antioxidant defense systems. Carrot seeds of a local cultivar (T-29) were primed with various concentration of KNO 3 (T 0 : unprimed (negative control), T 1 : hydroprimed (positive control), T 2 : 50 mM, T 3 :100mM, T 4 : 150 mM, T 5 : 200 mM, T 6 : 250 mM and T 7 : 300 mM) for 12 h each in darkness at 20 ± 2℃. Seed priming with 50 mM of KNO 3 significantly enhanced the seed germination (36%), seedling growth (28%) with maximum seedling vigor (55%) and also exhibited 16.75% more carrot root biomass under high temperature stress as compared to respective control. Moreover, enzymatic activities including peroxidase, catalase, superoxidase dismutase, total phenolic contents, total antioxidants contents and physiological responses of plants were also improved in response to seed priming under high temperature stress. By increasing the level of KNO 3 , seed germination, growth and root biomass were reduced. These findings suggest that seed priming with 50 mM of KNO 3 can be an effective strategy to improve germination, growth and yield of carrot cultivar (T-29) under high temperature stress in early cropping. This study also proposes that KNO 3 may induces the stress memory by heritable modulations in chromosomal structure and methylation and acetylation of histones that may upregulate the hormonal and antioxidant activities to enhance the stress tolerance in plants., (© 2024. The Author(s).)

Background: Hydrogen gas (H 2 ), a novel and beneficial gaseous molecule, plays a significant role in plant growth and development processes. Hydrogen-rich water (HRW) is regarded as a safe and easily available way to study the physiological effects of H 2 on plants. Several recent research has shown that HRW attenuates stress-induced seed germination inhibition; however, the underlying modes of HRW on seed germination remain obscure under non-stress condition., Results: In this current study, we investigated the possible roles of gibberellin (GA) and abscisic acid (ABA) in HRW-regulated seed germination in wax gourd (Benincasa hispida) through pharmacological, physiological, and transcriptome approaches. The results showed that HRW application at an optimal dose (50% HRW) significantly promoted seed germination and shortened the average germination time (AGT). Subsequent results suggested that 50% HRW treatment stimulated GA production by regulating GA biosynthesis genes (BhiGA3ox, BhiGA2ox, and BhiKAO), whereas it had no effect on the content of ABA and the expression of its biosynthesis (BhiNCED6) and catabolism genes (BhiCYP707A2) but decreased the expression of ABA receptor gene (BhiPYL). In addition, inhibition of GA production by paclobutrazol (PAC) could block the HRW-mediated germination. Treatment with ABA could hinder HRW-mediated seed germination and the ABA biosynthesis inhibitor sodium tungstate (ST) could recover the function of HRW. Furthermore, RNA-seq analysis revealed that, in the presence of GA or ABA, an abundance of genes involved in GA, ABA, and ethylene signal sensing and transduction might involve in HRW-regulated germination., Conclusions: This study portrays insights into the mechanism of HRW-mediated seed germination, suggesting that HRW can regulate the balance between GA and ABA to mediate seed germination through ethylene signals in wax gourd., (© 2024. The Author(s).)

Dragon fruit (Selenicereus undatus), known for its captivating appearance and remarkable nutritional profile, has garnered considerable attention in recent years. Despite its popularity, there's a dearth of research on optimal conditions for seed germination and early growth stages such as seedling shoot length, which are crucial for optimal crop yield. This study aims to bridge this gap by evaluating various growing media's performance on dragon fruit germination and early growth stages. Dragon fruit seeds were obtained from local markets in Pakistan and evaluated in five different growing media: cocopeat, peat moss, sand, vermiculite, and compost. Germination parameters were observed for 45 days, including seed germination percentage, mean germination time, and mean daily germination percentage, among others while early growth was monitored for 240 days. Statistical analysis was conducted using ANOVA and Tukey's HSD test. Significant differences were found among the growing media regarding germination percentage, mean germination time, and mean daily germination. Vermiculite exhibited the highest germination rate (93.33%), while compost showed the least (70%). Peat moss and sand media facilitated rapid germination, while compost showed slower rates. Stem length was significantly influenced by the growth media, with compost supporting the longest stems. Vermiculite emerged as the most effective medium for dragon fruit seed germination, while compost showed slower but steady growth. These findings provide valuable insights for optimizing dragon fruit cultivation, aiding commercial growers and enthusiasts in achieving higher yields and quality. Further research could explore additional factors influencing dragon fruit growth and development., (© 2024. The Author(s).)

Background: Seed aging, a natural and inevitable process occurring during storage. Oats, an annual herb belonging to the Gramineae family and pooideae. In addition to being a healthy food, oats serve as ecological pastures, combating soil salinization and desertification. They also play a role in promoting grassland agriculture and supplementing winter livestock feed. However, the high lipid and fat derivatives contents of oat seeds make them susceptible to deterioration, as fat derivatives are prone to rancidity, affecting oat seed production, storage, development, and germplasm resource utilization. Comparative studies on the effects of aging on physiology and cytological structure in covered and naked oat seeds are limited. Thus, our study aimed to determine the mechanism underlying seed deterioration in artificially aged 'LongYan No. 3' (A. sativa) and 'BaiYan No. 2' (A. nuda) seeds, providing a basis for the physiological evaluation of oat seed aging and serving as a reference for scientifically safe storage and efficient utilization of oats., Results: In both oat varieties, superoxide dismutase and catalase activities in seeds showed increasing and decreasing trends, respectively. Variance analysis revealed significant differences and interaction in all measured indicators of oat seeds between the two varieties at different aging times. 'LongYan No. 3' seeds, aged for 24-96 h, exhibited a germination rate of < 30%, Conductivity, malondialdehyde, soluble sugar, and soluble protein levels increased more significantly than the 'BaiYan No. 2'. With prolonged aging leading to cell membrane degradation, reactive oxygen species accumulation, disrupted antioxidant enzyme system, evident embryo cell swelling, and disordered cell arrangement, blocking the nutrient supply route. Simultaneously, severely concentrated chromatin in the nucleus, damaged mitochondrial structure, and impaired energy metabolism were noted, resulting in the loss of 'LongYan No. 3' seed vitality and value. Conversely, 'BaiYan No. 2' seeds showed a germination rate of 73.33% after 96 h of aging, consistently higher antioxidant enzyme activity during aging, normal embryonic cell shape, and existence of the endoplasmic reticulum., Conclusions: ROS accumulation and antioxidant enzyme system damage in aged oat seeds, nuclear chromatin condensation, mitochondrial structure damage, nucleic acid metabolism and respiration weakened, oat seed vigor decreased. 'LongYan No. 3' seeds were more severely damaged under artificial aging than 'BaiYan No. 2' seeds, highlighting their heightened susceptibility to aging effects., (© 2024. The Author(s).)

Background and Aims: Intra- and transgenerational plasticity may provide substantial phenotypic variation to cope with environmental change. Since assessing the unique contribution of the maternal environment to the offspring phenotype is challenging in perennial, outcrossing plants, little is known about the evolutionary and ecological implications of transgenerational plasticity and its persistence over the life cycle in these species. We evaluated how intra- and transgenerational plasticity interplay to shape the adaptive responses to drought in two perennial Mediterranean shrubs., Methods: We used a novel common garden approach that reduced within-family genetic variation in both the maternal and offspring generations by growing the same maternal individual in two contrasting watering environments, well-watered and drought, in consecutive years. We then assessed phenotypic differences at the reproductive stage between offspring reciprocally grown in the same environments., Key Results: Maternal drought had an effect on offspring performance only in Helianthemum squamatum. Offspring of drought-stressed plants showed more inflorescences, less sclerophyllous leaves and higher growth rates in both watering conditions, and heavier seeds under drought, than offspring of well-watered maternal plants. Maternal drought also induced similar plasticity patterns across maternal families, showing a general increase in seed mass in response to offspring drought, a pattern not observed in the offspring of well-watered plants. In contrast, both species expressed immediate adaptive plasticity, and the magnitude of intragenerational plasticity was larger than the transgenerational plastic responses., Conclusions: Our results highlight that adaptive effects associated with maternal drought can persist beyond the seedling stage and provide evidence of species-level variation in the expression of transgenerational plasticity. Such differences between co-occurring Mediterranean species in the prevalence of this form of non-genetic inheritance may result in differential vulnerability to climate change., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Lentil is a significant legume that are consumed as a staple food and have a significant economic impact around the world. The purpose of the present research on lentil was to assess the hydrothermal time model's capacity to explain the dynamics of Lens culinaris L. var. Markaz-09 seed germination, as well as to ascertain the germination responses at various sub-optimal temperatures (T) and water potentials (Ψ). In order to study lentil seed germination (SG) behavior at variable water potentials (Ψs) and temperatures (Ts). A lab experiment employing the hydrothermal time model was created. Seeds were germinated at six distinct temperatures: 15 0 С, 20 0 С, 25 0 С, 30 0 С, 35 0 С, and 40 0 С, with five Ψs of 0, -0.3, -0.6, -0.9, and - 1.2 MPa in a PEG-6000 (Polyethylene glycol 6000) solution., Results: The results indicated that the agronomic parameters like Germination index (GI), Germination energy (GE), Timson germination index (TGI), were maximum in 25 0 C at (-0.9 MPa) and lowest at 40 0 C in 0 MPa. On other hand, mean germination time (MGT) value was highest at 15 0 C in -1.2 MPa and minimum at 40 0 C in (-0.6 MPa) while Mean germination rate (MGR) was maximum at 40 0 C in (0 MPa) and minimum at 15 0 C in (-0.6 MPa)., Conclusions: The HTT model eventually defined the germination response of Lens culinaris L. var. Markaz-09 (Lentil) for all Ts and Ψs, allowing it to be employed as a predictive tool in Lens culinaris L. var. Markaz-09 (Lentil) seed germination simulation models., (© 2024. The Author(s).)

Arthraxon hispidus is an introduced, rapidly spreading, and newly invasive grass in the eastern United States, yet little is known about the foundational biology of this aggressive invader. Germination responses to environmental factors including salinity, pH, osmotic potential, temperature, and burial depth were investigated to better understand its germination niche. Seeds from six populations in the Mid-Atlantic US germinated 95% with an average mean time to germination of 3.42 days of imbibition in the dark at 23°C. Germination occurred across a temperature range of 8-37°C and a pH range of 5-10 (≥83%), suggesting that neither pH nor temperature will limit germination in many environments. Arthraxon hispidus germination occurred in high salinity (342 mM NaCl) and osmotic potentials as low as -0.83MPa. The NaCl concentration required to reduce germination by 50% exceeded salinity concentrations found in soil and some brackish water saltmarsh systems. While drought adversely affects A. hispidus, 50% germination occurred at osmotic potentials ranging from -0.25 to -0.67 MPa. Given the climatic conditions of North America, drought stress is unlikely to restrict germination in large regions. Finally, emergence greatly decreased with burial depth. Emergence was reduced to 45% at 1-2 cm burial depths, and 0% at 8 cm. Emergence depths in concert with adequate moisture, germination across a range of temperatures, and rapid germination suggests A. hispidus' seed bank may be short-lived in moist environments, but further investigation is warranted. Given the broad abiotic tolerances of A. hispidus and a widespread native range, A. hispidus has the potential to germinate in novel territories beyond its currently observed invaded range., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Beall et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)