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Male Idesia polycarpa, which display distinct morphological and physiological traits, exhibit greater adaptability to stressful environments than females. However, the connection between this adaptability and rhizosphere processes remains unclear. Here, we investigate the differences in root bacterial community structures between male and female plants at different developmental stages, identifying bacterial strains associated with plant sex through functional predictions. This study aims to inform the optimal allocation of male and female plants during cultivation and provide a theoretical basis for sex identification and breeding. Samples from seven-year-old male and female plants were collected during the flowering (May) and fruit ripening (October) stages. Rhizosphere nutrient content and bacterial diversity were analyzed using Illumina high-throughput sequencing technology. The results demonstrate that total nitrogen (TN), total carbon (TC), and available potassium (AK) varied between sexes at different times. No significant differences between male and female plants were observed in the Shannon, Simpson, and Chao1 indexes during the flowering period. However, the Chao1 and Shannon indexes were significantly higher at fruit maturity in male rather than female plants. The predominant phyla of rhizosphere bacteria were Pseudomonadota, Acidobacteriota, and Actinomycetes. Interestingly, from flowering to fruit ripening, the dominant phyla in both male and female plants shifted from Actinomycetes to Pseudomonadota. A significant correlation was observed between pH and AK and rhizosphere bacteria (p < 0.05), with metabolism being the main functional difference. This study provides preliminary insights into the functional predictions and analyses of bacteria associated with Idesia polycarpa. The above findings lay the groundwork for further investigation into the sex-specific differences in microbial flora across different developmental stages, elucidating the mechanisms underlying flora changes and offering theoretical support for the high-quality management of Idesia polycarpa. [ABSTRACT FROM AUTHOR]

Abstract [Objective] This study aims to explore the flowering characteristics and flower fragrance components and their release patterns of Rhus chinensis, so as to provide a basis for further development and utilization of floral fragrance of R. chinensis. [Methods] Scanning electron microscope was used to observe pollen morphology. Headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) techniques were used to analyze the main floral scent components in different flowering stages and daily change pattern. [Results] A total of 92 floral substances (29 terpenes, 19 aldehydes, 15 esters, 14 alcohols, 5 ketones, 4 olefins, 2 aromatic hydrocarbons, and 1 each of phenols, alkanes, acids, and others) were detected in different flowering periods. Its relative content was increased and then decreased, reaching a maximum (3.60 μg/g) at the full-flowering stage, with significant differences among the flowering stages. A total of 84 floral aroma substances were detected during full flowering stage. The release showed a parabolic daily variation trend, which was higher during the day than at night and reached the maximum at 18:00 (4.80 μg/g), and then continued to decrease and reached the lowest at 6:00, with 2.58 μg/g. Terpenes were the main floral substances of R. chinensis, with a relative content of about 70% of the total floral components. [Conclusion] R. chinensis is rich in floral components, with a clear diurnal rhythm. Terpenes are its main floral substances.

The escalation in the intensity, frequency, and duration of high-temperature (HT) stress is currently unparalleled, which aggravates the challenges for crop production. Yet, the stage-dependent responses of reproductive organs to HT stress at the morphological, physiological, and molecular levels remain inadequately explored in pivotal staple crops. This review synthesized current knowledge regarding the mechanisms by which HT stress induces abnormalities and aberrations in reproductive growth and development, as well as by which it alters the morphology and function of florets, flowering patterns, and the processes of pollination and fertilization in maize (Zea mays L.). We identified the stage-specific sensitivities to HT stress and accurately defined the sensitive period from a time scale of days to hours. The microspore tetrad phase of pollen development and anthesis (especially shortly after pollination) are most sensitive to HT stress, and even brief temperature spikes during these stages can lead to significant kernel loss. The impetuses behind the heat-induced impairments in seed set are closely related to carbon, reactive oxygen species, phytohormone signals, ion (e.g. Ca2+) homeostasis, plasma membrane structure and function, and others. Recent advances in understanding the genetic mechanisms underlying HT stress responses during maize sexual reproduction have been systematically summarized. [ABSTRACT FROM AUTHOR]

The impact of water deficit severity and the specific growth stages at which water stress is applied have been found to have significant implications for both tomato yield and fruit quality. Recent findings have highlighted the influence of water deficits during the reproductive phase on tomato fruit quality. This study aimed to assess the effects of deficit irrigation on tomato fruit quality and overall plant productivity. Cherry tomatoes (Solanum lycopersicum var. cerasiforme) were grown in a greenhouse from August to November 2022. Three distinct watering regimes were implemented: Daily watering (T1), watering every 3 days (T2) and watering every 7 days (T3), starting from the flowering stage and continuing through subsequent plant development stages. The mean soil metric potentials (SMP) were -4.9, -29.7 and -52.8 kPa for T1, T2 and T3, respectively. Various traits of fruit size, fruit biomass, total soluble solids (TSS), water content, glucose content and lycopene content were measured. Additionally, the overall plant biomass and root-to-shoot ratio were evaluated. The results revealed that traits of the fruit size, such as diameter, length, volume and fresh weight, were most favorable when plants were subjected to the T2 watering regime, while higher and lower watering frequencies led to smaller fruit sizes. Interestingly, the TSS concentration had the most pronounced response to drought stress, indicating increased fruit sweetness. However, the fruit water content, glucose content and lycopene content remained unaffected by the different watering regimes. Furthermore, plants subjected to the T3 with the minimum SMP at -196.4 kPa exhibited enhanced development of the root system, prioritizing resource acquisition such as water and mineral nutrients over shoot components. In conclusion, this study provided valuable insights for agricultural practitioners, offering a range of alternatives that can inform optimal irrigation strategies that effectively enhance the quality of cherry tomato yields. [ABSTRACT FROM AUTHOR]

Drought stress is one of the most important limiting factors for plant growth and soil fertility, which causes crop yield reduction. In order to investigate the relative expression of genes related to drought stress tolerance, four genotypes (including two sensitive and two resistant genotypes to moisture stress) of bread wheat as factor A were subjected to a factorial experiment on basis randomized complete block design with three replications under normal and drought stress at the beginning of flowering stage as factor B in the research farm of Azerbaijan Shahid Madani University. The results of analysis of variance showed a significant difference at least at 1% probability level between drought stress levels according to most studied traits. Based on the results from the comparison of means of traits, the high tolerance of Eroum cultivar to drought stress was due to the higher increase in MDA and H2O2 and lower decrease in traits of chlorophyll a, total chlorophyll content, carotenoid content. In addition, the Mihan cultivar was more tolerant to drought stress because of the higher increase of proline, carotenoid, POX, and CAT, due to drought stress. The expression of genes in the examined samples was performed by semi-quantitative polymerase chain reaction in three replicates. Glutathione peroxidase gene (GAPDH) was used as housekeeping gene. Examining the relative expression level of antioxidant genes showed that the high tolerance of Mihan cultivar to drought stress can probably be attributed to the high activity of catalase and ascorbate peroxidase enzymes and the high tolerance of Arum cultivar to the higher activity of antioxidant enzymes proline synthetase, peroxidase and attributed to superoxide dismutase. Considering that the antioxidant genes catalase, ascorbate peroxidase, proline synthetase, peroxidase, and superoxide dismutase in tolerant cultivars showed a significant increase in expression under stress and normal conditions compared to sensitive cultivars under the same stress and normal conditions; so, this genes may induce tolerance to drought stress in plants under stress conditions. [ABSTRACT FROM AUTHOR]

Flowering regulation is a reflection of plant self-adaptation to the environment and is the main determinant of plant yield. The quantitative trait loci (QTL) mapping of agronomic traits associated with the flowering stage of Agropyron Gaertn. was conducted using a cross-pollinated (CP) hybrid population with a total of 113 plant lines between A. mongolicum Keng Z2098 and A. cristatum (L.) Gaertn. Z1842 under four different environmental conditions and the genetic map constructed of 1,023 single-nucleotide polymorphism (SNP) markers. The results showed that 28 QTLs were detected on seven linkage groups. Each QTL explained 0.39–18.46% of the phenotypic variation, with a logarithm of odds (LOD) value ranging from 2.52 to 30.51. Specifically, QTLs were identified for various characteristics: one QTL identified for tiller number (TN), two for plant height (PH), three for days-to-flowering (DTF), five for flag leaf length (FLL), three for flag leaf width (FLW), three for spike length (SL), eight for spike width (SW), one for spikelet number per spike (SNS), and two for flower number per spike (FNS). One stable QTL controlling the SW was detected in two environments at the same loci and was located at 26 cM (Marker29867–Marker26864) on chromosome 5, showing a positive genetic effect. The two QTL enrichment regions suggested that the QTLs might contribute to trait correlation or pleiotropic genes. The identified QTLs potentially offer utility for marker-assisted breeding selection. [ABSTRACT FROM AUTHOR]

Nymphaea 'Eldorado', a valuable water lily, is a well-known fragrant plant in China. Studying the temporal and spatial characteristics of the floral components of this plant can provide a reference for the further development and utilization of water lily germplasm resources. In this study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS) was used to explore the types and relative contents of floral components at different flowering stages (S1: bud stage; S2: initial-flowering stage; S3: full-flowering stage; S4: end-flowering stage) and in different floral organs of N. 'Elidorado', combined with the observation of the microscopic structure of petals. A total of 60 volatile organic compounds (VOCs) were detected at different flowering stages, and there were significant differences in floral VOCs at different flowering stages and in different flower organs. The volatile compounds of N. 'Eldorado' can be divided into seven chemical classes,, namely, alkenes, alcohols, esters, aldehydes, ketones, alkanes, and others; the most common were alkenes and alkanes. A total of 39, 44, 47, and 42 volatile compounds were detected at S1, S2, S3, and S4. The VOCs present in high concentrations include benzaldehyde, benzyl alcohol, benzyl acetate, trans-α-bergamotene, α-curcumene, cis-α-farnesene, and so on. The types and total contents of volatiles at the full-flowering stage were higher than at other flowering stages. Comparing the VOCs in different parts of flower organs, it was found that the contents of alcohols, esters, and aldehydes were greatest in the petals, the alkenes in stamens were abundant with a relative content of up to 54.93%, and alkanes in the pistil were higher than in other parts. The types and total contents of volatiles in the stamens of N. 'Eldorado' were higher than those in other flower organs; they were the main part releasing fragrance. The observation of petal microstructure revealed that the size and quantity of the papillae on the epidermises of petals, the number of intracellular plastids, and the aggregates of floral components (osmophilic matrix granules) were significantly higher at the full-flowering stage than at the other flowering stages. This study suggested the main flowering stage and location at which the floral VOCs are released by N. 'Eldorado' and provided a reference for guiding the breeding of this water lily, exploring genetic patterns and developing related products. [ABSTRACT FROM AUTHOR]

Introduction: Lentil is a rich source of protein, fiber, minerals, antioxidants, folate, zinc, selenium, iron, and low amounts of fat and carbohydrates. Increasing water shortage and drought stress will be a major threat to global lentil production. The present study was conducted to determine the morphophysiological traits and grain of yield under normal and drought stress conditions, investigate tolerance indices and identify drought tolerance in some lentil genotypes. Materials and methods: In this experiment, twenty - four lentil genotypes were evaluated in the research farm of Shahrekord Faculty of Agriculture in two drought-stress environments and the normal conditions of the region in two separate randomized complete block designs with three replications experiments. In the 50% flowering stage, drought stress was done by completely stopping irrigation for the genotypes. Sampling was done at the end of the growing season. In this experiment, morphophysiological and yield traits were measured. Results and discussion: The results of composite data analysis showed that the effect of environment, genotype and the interaction effect of genotype × environment were significant on most traits. The share of these sources of variation in diversity of triats was different and environment placed on the most role in the diversity of seed yield (55.27%), genotype in the diversity of 100 seed weight (64.6%) and the number of single seed pods (53.9%). Seed yield in normal agricultural conditions has a positive correlation with most of the traits. In addition, under stress conditions, more traits had a significant correlation with grain yield. STI and GMP indices were highly correlated with yield in both environments and these indices can be used to select the superior genotype. Examining the main components of the indicators showed that the first component and two components justify 97.66% of the changes, the first component was introduced as a semi-tolerant component and the second component as a tolerant component. The results of the cluster analysis put the genotypes in three general groups. The results of cluster analysis based on STI and GMP indices put the genotypes in three separate groups. Conclusion: One of the main goals of production programs in arid and semi-arid regions is the screening of germplasm in different stages of plant growth. The results of the present research showed that drought stress in the reproductive stage reduces the morphophysiological traits and yield of lentil genotypes. Based on the results of seed yield, Kimia genotype with the lowest yield loss is known as the tolerant variety and C113 variety with the highest yield loss is known as the sensitive variety. Based on the results of seed yield, Kimia genotype with the lowest yield loss is known as the tolerant variety and C113 variety with the highest yield loss is known as the sensitive variety. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.), a forage legume known for its moderate salt–alkali tolerance, offers notable economic and ecological benefits and aids in soil amelioration when cultivated in saline–alkaline soils. Nonetheless, the limited stress resistance of alfalfa could curtail its productivity. This study investigated the salt tolerance and growth-promoting characteristics (in vitro) of four strains of plant growth-promoting rhizobacteria (PGPR) that were pre-selected, as well as their effects on alfalfa at different growth stages (a pot experiment). The results showed that the selected strains belonged to the genera Priestia (HL3), Bacillus (HL6 and HG12), and Paenibacillus (HG24). All four strains exhibited the ability to solubilize phosphate and produce indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Among them, except for strain HG24, the other strains could tolerate 9% NaCl stress. Treatment with 100 mM NaCl consistently decreased the IAA production levels of the selected strains, but inconsistent changes (either enhanced or reduced) in terms of phosphate solubilization, ACC deaminase, and exopolysaccharides (EPS) production were observed among the strains. During the various growth stages of alfalfa, PGPR exhibited different growth-promoting effects: at the seedling stage, they enhanced salt tolerance through the induction of physiological changes; at the flowering stage, they promoted growth through nutrient acquisition. The current findings suggest that strains HL3, HL6, and HG12 are effective microbial inoculants for alleviating salt stress in alfalfa plants in arid and semi-arid regions. This study not only reveals the potential of indigenous salt-tolerant PGPR in enhancing the salt tolerance of alfalfa but also provides new insights into the mechanisms of action of PGPR. [ABSTRACT FROM AUTHOR]

Male Idesia polycarpa, which display distinct morphological and physiological traits, exhibit greater adaptability to stressful environments than females. However, the connection between this adaptability and rhizosphere processes remains unclear. Here, we investigate the differences in root bacterial community structures between male and female plants at different developmental stages, identifying bacterial strains associated with plant sex through functional predictions. This study aims to inform the optimal allocation of male and female plants during cultivation and provide a theoretical basis for sex identification and breeding. Samples from seven-year-old male and female plants were collected during the flowering (May) and fruit ripening (October) stages. Rhizosphere nutrient content and bacterial diversity were analyzed using Illumina high-throughput sequencing technology. The results demonstrate that total nitrogen (TN), total carbon (TC), and available potassium (AK) varied between sexes at different times. No significant differences between male and female plants were observed in the Shannon, Simpson, and Chao1 indexes during the flowering period. However, the Chao1 and Shannon indexes were significantly higher at fruit maturity in male rather than female plants. The predominant phyla of rhizosphere bacteria were Pseudomonadota, Acidobacteriota, and Actinomycetes. Interestingly, from flowering to fruit ripening, the dominant phyla in both male and female plants shifted from Actinomycetes to Pseudomonadota. A significant correlation was observed between pH and AK and rhizosphere bacteria (p < 0.05), with metabolism being the main functional difference. This study provides preliminary insights into the functional predictions and analyses of bacteria associated with Idesia polycarpa. The above findings lay the groundwork for further investigation into the sex-specific differences in microbial flora across different developmental stages, elucidating the mechanisms underlying flora changes and offering theoretical support for the high-quality management of Idesia polycarpa.

High temperature around flowering has a serious impact on the growth and development of maize. However, few maize genes related to flowering under heat stress have been confirmed, and the regulatory mechanism is unclear. To reveal the molecular mechanism of heat tolerance in maize, two maize hybrids, ZD309 and XY335, with different heat resistance, were selected to perform transcriptome and metabolomics analysis at the flowering stage under heat stress. In ZD309, 314 up-regulated and 463 down-regulated differentially expressed genes (DEGs) were detected, while 168 up-regulated and 119 down-regulated DEGs were identified in XY335. By comparing the differential gene expression patterns of ZD309 and XY335, we found the "frontloaded" genes which were less up-regulated in heat-tolerant maize during high temperature stress. They included heat tolerance genes, which may react faster at the protein level to provide resilience to instantaneous heat stress. A total of 1062 metabolites were identified via metabolomics analysis. Lipids, saccharides, and flavonoids were found to be differentially expressed under heat stress, indicating these metabolites' response to high temperature. Our study will contribute to the identification of heat tolerance genes in maize, therefore contributing to the breeding of heat-tolerant maize varieties. [ABSTRACT FROM AUTHOR]

Background: Salinity is a major limitation for rice farming due to climate change. Since salt stress adversely impact rice plants at germination, seedling, and reproductive stages resulting in poor crop establishment and reduced grain yield, enhancing salt tolerance at these vulnerable growth stages will enhance rice productivity in salinity prone areas. Methods and results: An introgression line (ILs) population from a cross between a high yielding cultivar 'Cheniere' and a salt tolerant donor 'TCCP' was evaluated to map quantitative trait loci (QTLs) for traits associated with salt tolerance at germination, seedling, and reproductive stages. Using a genotyping-by-sequencing based high density SNP linkage map, a total of 7, 16, and 30 QTLs were identified for five germination traits, seven seedling traits, and ten reproductive traits, respectively. There was overlapping of QTLs for some traits at different stages indicating the pleiotropic effects of these QTLs or clustering of linked genes. Candidate genes identified for salt tolerance were OsSDIR1 and SERF for the seedling stage, WRKY55 and OsUBC for the reproductive stage, and MYB family transcription factors for all three stages. Gene ontology analysis revealed significant GO terms related to nucleotide binding, protein binding, protein kinase activity, antiporter activity, active transmembrane transporter activity, calcium-binding protein, and F- box protein interaction domain containing protein. Conclusions: The colocalized QTLs for traits at different growth stages would be helpful to improve multiple traits simultaneously using marker-assisted selection. The salt tolerant ILs have the potential to be released as varieties or as pre-breeding lines for developing salt tolerant rice varieties. [ABSTRACT FROM AUTHOR]

Context. As global temperatures increase, heat waves of >30°C for at least 3 days are projected to become more frequent during reproductive development of wheat, causing reductions in grain yield. Breeding for tolerance is difficult under field conditions owing to the unpredictable timing and intensity of natural heat events and the narrow developmental windows of sensitivity. Aims. We report on a series of experiments designed to explore genetic variability for floret sterility induced by natural heat waves in the field by targeting a sensitive development stage. Methods. Our method involved sowing late, and the use of auricle distance to identify main tillers exposed to heat events at a sensitive developmental stage (booting). Key results. Substantial genetic variation was found for tolerance of grain set to natural heat waves, with a broad-sense heritability estimate of 0.94 for heat-exposed stems compared with 0.72 for non-stressed controls. An auricle distance of 1-3 cm was established as a phenotypic marker for tagging stems at the sensitive stage of development, and the optimal number of spikes to assess was determined as 10-15 per plot. A validation study with durum lines previously classified as tolerant/intolerant under glasshouse conditions showed agreement in ranking of genotypes at the extremes of tolerance. Conclusions. We demonstrate that it is possible to screen wheat genotypes for stage-specific tolerance to natural heat waves in the field. Implications. The protocol described could provide a low-cost method for evaluating heat tolerance in wheat, with relevance to commercial field production conditions. The approach allows tolerance to be assessed at a single stage of reproductive development, which should allow greater heritability in field assessments. [ABSTRACT FROM AUTHOR]

Nymphaea ‘Eldorado’, a valuable water lily, is a well-known fragrant plant in China. Studying the temporal and spatial characteristics of the floral components of this plant can provide a reference for the further development and utilization of water lily germplasm resources. In this study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS) was used to explore the types and relative contents of floral components at different flowering stages (S1: bud stage; S2: initial-flowering stage; S3: full-flowering stage; S4: end-flowering stage) and in different floral organs of N. ‘Elidorado’, combined with the observation of the microscopic structure of petals. A total of 60 volatile organic compounds (VOCs) were detected at different flowering stages, and there were significant differences in floral VOCs at different flowering stages and in different flower organs. The volatile compounds of N. ‘Eldorado’ can be divided into seven chemical classes,, namely, alkenes, alcohols, esters, aldehydes, ketones, alkanes, and others; the most common were alkenes and alkanes. A total of 39, 44, 47, and 42 volatile compounds were detected at S1, S2, S3, and S4. The VOCs present in high concentrations include benzaldehyde, benzyl alcohol, benzyl acetate, trans-α-bergamotene, α-curcumene, cis-α-farnesene, and so on. The types and total contents of volatiles at the full-flowering stage were higher than at other flowering stages. Comparing the VOCs in different parts of flower organs, it was found that the contents of alcohols, esters, and aldehydes were greatest in the petals, the alkenes in stamens were abundant with a relative content of up to 54.93%, and alkanes in the pistil were higher than in other parts. The types and total contents of volatiles in the stamens of N. ‘Eldorado’ were higher than those in other flower organs; they were the main part releasing fragrance. The observation of petal microstructure revealed that the size and quantity of the papillae on the epidermises of petals, the number of intracellular plastids, and the aggregates of floral components (osmophilic matrix granules) were significantly higher at the full-flowering stage than at the other flowering stages. This study suggested the main flowering stage and location at which the floral VOCs are released by N. ‘Eldorado’ and provided a reference for guiding the breeding of this water lily, exploring genetic patterns and developing related products.

• Sanqi flowers have a higher quality under organic vs conventional management. • The flavonoid biosynthesis pathway was positively influenced by organic management. • The full blooming stages is the best time to harvest the Sanqi flowers. The simulative habitat cultivation of Panax notoginseng (Sanqi) under pine forests using organic management (OM) enhances the quality of Sanqi roots. However, the impact of the OM on the quality of Sanqi flowers remains unknown. The Sanqi flowers cultivated under OM compared with those cultivated under CM (conventional management) exhibited higher levels of flavonoids, saponins, and polysaccharides, as well as dry/fresh weight. Principal component analysis demonstrated that metabolites were predominantly influenced by the cultivation patterns followed by the flowering stage. Several of the differentially abundant metabolites and expressed genes were upregulated in Sanqi flowers cultivated under OM. The flavonoid biosynthesis pathway was highly affected by the cultivation systems and flowering stages, mediated by the essential genes C4H, HCT, C3′H, DFR, and FLS. Flavonoid levels peaked at full bloom, indicating that this is the optimum stage for harvesting Sanqi flowers. Our findings are of great value for developing optimal cultivation and harvest practices. [ABSTRACT FROM AUTHOR]

Heat stress at the flowering stage significantly impacts rice grain yield, yet the number of identified genes associated with rice heat tolerance at this crucial stage remains limited. This study focuses on elucidating the function of the heat-induced gene reduced heat stress tolerance 1 (OsRHS). Overexpression of OsRHS leads to reduced heat tolerance, while RNAi silencing or knockout of OsRHS enhances heat tolerance without compromising yield, as assessed by the seed setting rate. OsRHS is localized in the cytoplasm and mainly expressed in the glume and anther of spikelet. Moreover, OsRHS was found to interact with the HSP protein cHSP70-4, and the knockout of cHSP70-4 resulted in increased heat tolerance. Complementation assays revealed that the knockout of cHSP70-4 could restore the compromised heat tolerance in OsRHS overexpression plants. Additional investigation reveals that elevated temperatures can amplify the bond between OsRHS and cHSP70-4 within rice. Furthermore, our findings indicate that under heat stress conditions during the flowering stage, OsRHS plays a negative regulatory role in the expression of many stress-related genes. These findings unveil the crucial involvement of OsRHS and cHSP70-4 in modulating heat tolerance in rice and identify novel target genes for enhancing heat resilience during the flowering phase in rice., (© 2024 John Wiley & Sons Ltd.)