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Free proline, termed proline, is a biomarker used for diagnosing drought stress in plants. A previously developed proline–ninhydrin reaction-based paper sensor could quickly and easily detect proline, but it was limited by low sensitivity. In this study, we developed an enclosed multilayer paper-based microfluidic sensor with high sensitivity for the quantitative detection of proline in plants. The multilayer paper-based sensor was manufactured using simple wax printing and origami methods, and contained an internal mixing channel to allow good mixing of the proline with ninhydrin, increasing the proline–ninhydrin reactivity and providing accurate and sensitive proline detection. By preloading ninhydrin onto the sample loading area, uniform coloration of the sensing window was achieved, allowing quantitative analysis of various proline concentrations using a constant reaction time. Only the sensing window and sample loading area were exposed to limit sample evaporation and contamination from the external environment. The LOD of the fabricated sensor was 23 μM, which is approximately 29-fold lower than that of the previously proposed paper sensor (657 μM). Samples were extracted from A. thaliana plants subjected to drought stress for proline detection. The proline concentrations measured using the developed paper sensor and a spectrophotometric method were not statistically significant at a confidence level of 95%. Therefore, the developed sensor can be applied to measure proline concentrations precisely in the field with a low detection limit. The developed paper-based sensor can be used to detect the early stages of drought in plants and thus improve crop productivity. Image 1 • An enclosed multilayer paper-based microfluidic sensor for proline quantification is manufactured. • The enclosed multilayer sensor structure avoids sample evaporation and contamination. • The sensor detects proline with a LOD of 23 μM. • The sensor is suitable for the early detection of drought stress in plants. • The measured proline concentration is similar to that measured by spectrometry. [ABSTRACT FROM AUTHOR]

Drought is a climate problem which has become a major constraint on crop production and causing social and economic devastation to local farmers worldwide. This climate issue has been the most destructive factors for rice cultivation and therefore requires scientist to be more responsive to this problem. In this study, we investigated the effect of drought stress at an early vegetative stage on plant growth, physiology and root anatomy of a few selected known tolerance rice varieties. Rice seeds were first germinated on moisturized filter papers before transplanted into polybags filled with topsoils. Drought treatment was imposed 4 weeks after transplanting until the first sign of rolled leaves were seen. In this study, drought had no major impact on plant height but reduced dry matter accumulation was seen in all varieties. Drought exposure had also triggered changes in the overall content of chlorophyll but not in the composition of chlorophyll a and b. Meanwhile, plants subject to drought in some parameters had better root morphology and structure compared to normal irrigation, especially in Kuku Belang, Apami and Huma Wangi Lenggong. However, depending on the variety, the responses varied in different order of magnitude. [ABSTRACT FROM AUTHOR]

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This document is an editorial from the journal Frontiers in Plant Science titled "The role of lipids in abiotic stress responses." It discusses the importance of lipids in plant responses to environmental stress, such as drought and high temperatures. The editorial highlights the complex relationship between lipids and stress adaptation in plants and emphasizes the need for further research in lipidomics and lipid signaling pathways. The document also mentions specific research papers included in the journal issue, which explore topics such as lipid remodeling in maize hybrids under drought, lipid modulation in peanuts under heat stress, the effect of temperature on lipid accumulation in microalgae, and the identification and expression analysis of KCS genes in soybean in response to abiotic stress. Overall, understanding the role of lipids in stress response is crucial for developing resilient and stress-tolerant crops. [Extracted from the article]

Context: Cannabis is a herbaceous annual plant that belongs to the Cannabaceae family, which is used in the production of fibre, paper, oil and pharmaceutical products. Aims: The aim of this study was to identify drought-tolerant ecotypes and medicinal and industrial populations. Methods: Due to the medicinal and industrial importance of cannabis, 12 cannabis ecotypes were collected from different regions of Iran. Then, their agronomic and phytochemical characteristics were evaluated under different soil moisture conditions. Key results: The soil moisture levels had significant effects (P < 0.01) on the studied traits except for the 1000 seed weight. Based on duration of the growth period, the Tabas and Dasht-e-Moghan ecotypes were identified as early and late maturing ecotypes, respectively. Also, the highest stem dry weight and stem height/diameter ratio and the lowest seed yield were related to the Dasht-e-Moghan ecotype, which is valuable for fibre production. Based on seed yield (relative reduction) and some tolerance indexes, the Tabas and Tabrize ecotypes were shown to be the most tolerant and sensitive ecotypes, respectively. As soil moisture decreased, tetrahydrocannabinol levels increased and cannabidiol levels decreased. The highest amount of tetrahydrocannabinol was related to the Qom ecotype at 50% soil moisture and the highest amount of cannabidiol was related to the Rasht ecotype at 100% soil moisture. Conclusions: Generally, these ecotypes had different responses to soil moisture. Some ecotypes were valuable in terms of the production of pharmaceutical metabolites and some in terms of fibre production. Implications: Tolerant and sensitive ecotypes might be considered in production and also breeding programs. Cannabis is a herbaceous annual plant that belongs to the Cannabaceae family, and is used in the production of fibre, paper and oil. This plant has been used for the treatment of rheumatism, epilepsy, asthma, skin burns, gastrointestinal activity, osteoporosis, schizophrenia, cardiovascular disorders, cancer and metabolic syndrome-related disorders. Generally, our findings showed that these ecotypes had different responses to soil moisture, and some ecotypes were valuable in terms of the production of pharmaceutical metabolites and some in terms of fibre production. [ABSTRACT FROM AUTHOR]

Betulin and oleanolic acid are pentacyclic triterpene compounds with a broad range of biological and medicinal properties. Herein, we demonstrated that 2-year-old white birch saplings were capable of synthesizing betulin and oleanolic acid, and the accumulation of these compounds was significantly affected by seasonal and environmental factors. Indeed, the triterpenes accumulated mainly in the stem bark, with little in the root bark and leaves. From May to October, betulin and oleanolic acid stem bark accumulation displayed an inverted 'V' curve, peaking in late July to late August (warmest summer months in Haerbin, China). Interestingly, low nitrogen levels promoted root bark and leaf accumulation of oleanolic acid, while high nitrogen amounts were more favorable to oleanolic acid and betulin accumulation in the stem bark. Moderate and mild drought during the accumulation peak period promoted oleanolic acid and betulin accumulation in the stem bark. Serious shortage of soil moisture inhibited the accumulation of both triterpenes. From July to August, high nitrogen (N3) treatment increased lupeol synthase (BPW) and beta-amyrin synthase (BPY) gene expression in the stem bark. Water stress, especially mild and moderate, induced BPW and BPY expression and downregulated cycloartenol synthase (BPX) in the stem bark. This study provides a strong basis for understanding triterpenoid synthesis in birch at the molecular level. [ABSTRACT FROM AUTHOR]

[Objective] Scutellaria baicalensis Georgi (SBG) is a Chinese medicine. This paper studies the combined effect of initial soil water content and progressive drought on physiological traits and quality of SBG. [Method] The pot experiment was conducted in a mobile water shelter. The initial soil water content in the pots were controlled at 40%, 60% and 80% of the field capacity (FC) to represent severe, moderate, and mild drought, respectively. In each treatment, we measured the biomass, photosynthetic characteristics, osmotic substances, activities of antioxidant enzymes and active ingredients of the plants. [Result] ① No significant difference in biomass accumulation was found between the treatments. ② During the stress period, baicalin content was significantly higher in the 80%FC treatment, baicalein content was significantly higher in the 40%FC treatment and the baicalin content decreased with initial soil water treatment in the order of 40%FC>60%FC>80%FC. When the soil water content was 40%FC and 60%FC, the baicalin content was 17.3% and 11.3% higher than that when soil water content was 80%FC. Change in soil water contents did not have a significant impact on baicalein content. ③ Net photosynthetic rate, transpiration rate, stomatal conductance and intercellular carbon dioxide concentration all decreased as the plants grew, regardless of the soil water treatments. 8-10 d after the onset of water stress, the net photosynthetic rate did not show significant differences between the 60%FC and 80%FC treatments. ④ Under water stress, the content of malondialdehyde and proline in all treatments increased as the plants grew. The proline content was the highest in the 80%FC treatment, reaching 121.66 µg/g. ⑤ The activities of POD and CAT responded to water stress similarly, both increasing gradually as water stress persisted. The impact of soil water on activity of SOD was ranked in the order of 40%FC>60%FC>80%FC. ⑥ The active ingredients were higher in the 40%FC and 60%FC treatments. [Conclusion] Severe progressive drought with the soil water content kept at 40%FC reduced photosynthesis and increased baicalein content, osmolytes and activity of antioxidant enzymes. Mild and severe droughts by keeping the soil water content at 40%FC and 60%FC can improve accumulation of active ingredients in SBG. [ABSTRACT FROM AUTHOR]

Drought stress is one of the most important abiotic stresses which causes many yield losses every year. This paper presents a comprehensive review of recent advances in international drought research. First, the main types of drought stress and the commonly used drought stress methods in the current experiment were introduced, and the advantages and disadvantages of each method were evaluated. Second, the response of plants to drought stress was reviewed from the aspects of morphology, physiology, biochemistry and molecular progression. Then, the potential methods to improve drought resistance and recent emerging technologies were introduced. Finally, the current research dilemma and future development direction were summarized. In summary, this review provides insights into drought stress research from different perspectives and provides a theoretical reference for scholars engaged in and about to engage in drought research. [ABSTRACT FROM AUTHOR]

[Objective] Crops often suffer from interval drought and rehydration (rainfall or irrigation) during the whole growth period, especially in arid and semi-arid areas. Under drought stress, the growth and development of crops are inhibited, and the yield is reduced; meanwhile, the plants drought tolerance will be induced. In order to compensate loss of yield or growth induced by drought stress, crop often shows compensatory after rehydration, which produces compensation or even over compensation effect on yield. The compensation effect of post drought is the result of crop's positive response to drought stress and compensatory growth after rehydration. It can effectively improve crop yield and water use efficiency in crop production in arid areas. [Methods] Source sink relationship is widely used to explain the crop yield formation, and regulating the source sink relationship is one of key way to improve crop yield. The compensation effect of post drought is highly related to the source sink response of crops. Based on the current research progress, this paper tries to explain the compensation effect of post drought in source and ink way. [Results] Under the drought stress, in the source, the stomata were closed, photosynthesis was decreased and soluble carbohydrate accumulation was increased, while sink activity was often increased. After rehydration, the metabolism of soluble carbohydrate in the source (leaf) was enhanced, which enhanced the photosynthesis and the ability of carbohydrate synthesis; meanwhile, the sink activity (grain) was maintained at a high level, and the rate of assimilate unloading and accumulation was accelerated; the assimilate in the flow remained at a high level. During this process, the activities of sucrose invertase (INV), ell wall invertase (CW-INV) and fructan exohydrolases (1-FEH w3) play important roles in the source sink response to the compensation effect of post-drought. [Conclusion] This paper integrated the mechanism of compensation effect of post drought in the perspective of source sink relationship, which provides a theoretical basis for understanding the mechanism of compensation effect of post drought and improving crop water efficient in arid areas. [ABSTRACT FROM AUTHOR]

Atriplex canescens is widely cultivated as drought and salt-tolerant fodder in arid regions of Northwest China, which is used for photoremediation of degraded land and soil and water conservation. To explore the growth performance of A. canescens when exposed to drought and salt stress, seedlings were treated with a range of drought stress (WC1: 75 ± 3.6%, WC2: 49 ± 2.9% and WC3: 27 ± 2.5% of soil water content) and the corresponding drought stress with additional sodium salt supplementation (NaCl:Na2SO4 = 1:1 with the total concentration of Na+ set to 150 mM). The findings of this paper indicated that moderate sodium salt could stimulate the growth of A. canescens and effectively alleviate the deleterious impact of drought stress by increasing the turgor potential (ψt) and relative water content (RWC) and decreasing the leaf water osmotic potential (ψs). Furthermore, the photosynthetic capacity was improved and the negative effects of drought stress on photosystem II (PSII) were mitigated. The extra 150 mM sodium salt also markedly increased the contribution of Na+ to ψs and the contribution of betaine to ψs. In summary, these results indicate that A. canescens can adapt to drought stress by accumulating enough Na+ for osmotic adjustment (OA). Additionally, this paper is aimed to provide a fundamental basis for the utilization and cultivation of A. canescens as a favored pasture crop in the Qaidam basin, thus increasing the ecological and environmental benefits for arid regions worldwide. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Shanxi Agricultural Sciences is the property of Shanxi Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Wheat (Triticum aestivum L.) is one of the most widely grown and vital cereal crops, containing a high percentage of basic nutrients such as carbohydrates and proteins. Drought stress is one of the most significant limitations on wheat productivity. Due to climate change influences plant development and growth, physiological processes, grain quality, and yield. Drought stress has elicited a wide range of plant responses, namely physiological and molecular adaptations. Biopriming is one of the recent attempts to combat drought stress. Mitigating the harmful impact of abiotic stresses on crops by deploying extreme-habitat-adapted symbiotic microbes. The purpose of this study was to see how biopriming Triticum aestivum grains affected the effects of inoculating endophytic fungi Aspergillus fumigatus ON307213 isolated from stressed wheat plants in four model agricultural plants (Gemmiza-7, Sids-1, Sakha8, and Giza 168). And its viability in reducing drought stress through the use of phenotypic parameters such as root and shoot fresh and dry weight, shoot and root length, and so on. On a biochemical and physiological level, enzymatic parameters such as catalase and superoxidase dismutase are used. Total phenolics, flavonoids, and photosynthetic pigments are non-enzymatic parameters. Making use of molecular techniques such as reverse transcriptase polymerase chain reaction (RT-PCR). Results: It has been found that using Aspergillus fumigatus as a biological biopriming tool can positively impact wheat plants experiencing drought stress. The total biomass of stressed wheat plants that had been bio-primed rose by more than 40% as compared to wheat plants that had not been bio-primed. A. fumigatus biopriming either increased or decreased the amount of enzymatic and non-enzymatic substances on biochemical scales, aside from the noticeable increase in photosynthetic pigment that occurs in plants that have been bio-primed and stressed. Drought-resistant genes show a biopriming influence in gene expression. Conclusions: This is the first paper to describe the practicality of a. fumigatus biopriming and its effect on minimizing the degrading effects of drought through water limitation. It suggests the potential applications of arid habitat-adapted endophytes in agricultural systems. [ABSTRACT FROM AUTHOR]

Salt and heat tolerance are important traits for a germinating seed. Not all plants harbor the traits, but mutualistic bacteria can help in salt and heat stress tolerance. In order to determine the potential to tolerate the stress, 12 isolates from tomato rhizosphere were investigated. The germination tests were taken on germination paper with different temperatures spanning from 35 and 45 °C with the bacterial inoculum. The salt tolerance was tested using bile salt and sodium chloride. The pH tolerance was tested on pH 3 and pH 5. Among all the isolates, Bacillus subtilis (MBM 5) was found to be of significant importance. It was identified using 16S rDNA sequencing method. Homology analysis of the 16S rDNA showed it to be B. subtilis and submitted to Genebank with accession number OP777493.1. The germination stage of tomato seedlings treated with a strain of Bacillus subtilis at drought condition (pH-3 and 5, 7 and 9; temperature 15°C, 25°C, 35°C and 45°C) showed significant improvement from the control treatment. The germinating seeds were able to withhold a higher acidity after inoculation of the bacterial strain at time intervals of 3 to 12 hours. Tomato plants benefited from inoculum treatment, with a significant increase in stem bulk and root length. The results of this investigation support the idea that B. subtilis (MBM 5) can be utilized to fertilize tomato seeds and produce other bioproducts. [ABSTRACT FROM AUTHOR]

Common purslane (Portulaca oleracea) is a halophyte, consumed not only as an edible vegetable but also as a traditional medicine. This plant can adapt to extreme salinity and drought conditions and their effects on plant growth, yield and quality were elucidated, but the effects on seed germination was still unclear. Seed germination is an important stage for establishing P. oleracea seedlings that contribute to plant yield and productivity. Thus, the objective of the present study was to examine the individual effects of salinity and drought stress at different levels on the characteristics of seed germination, which the seeds suffered from −0.22, −0.45, −0.89, and −1.78 MPa osmotic stresses induced by polyethylene glycol (PEG), or from 50, 100, 200, and 400 mM NaCl stresses with equivalent osmotic pressures. The seeds sown in petri dishes containing filter paper layers that were flooded with NaCl or PEG-6000 solutions for the treatments and germination parameters were determined daily for 15 days. Data showed that germination percentage (GP), germination rate (GR), germination energy (GE), and mean germination time (MGT) were significantly decreased with increasing levels of salt and osmotic stresses, suggesting that the salinity and drought stress reduced the germination capability of seeds. Moreover, the seeds maintained germination with PEG osmotic pressure above −0.22 MPa, but not with NaCl concentration greater than 50 mM that induced a similar osmotic pressure, suggesting that the ion toxicity effect on the seed germination might be higher than the osmotic effects. [ABSTRACT FROM AUTHOR]

It is estimated that 40–70%, 80–90% and 50–90% of the conventional macronutrients N, P and K applied to the soil are lost, respectively, resulting in considerable loss of resources. Compared to conventional fertilizers, nanofertilizers have the advantages of controlled release, high nutrient utilization, low cost and relatively low environmental pollution due to their small size (1–100 nm) and high specific surface area. The application of nanofertilizers is an up-and-coming field of agricultural research and is an attractive and economical substitute for common fertilizers which can boost global food productivity sustainably. Foliar fertilization is a popular way to satisfy the needs of higher plants. Because of its small application dose, faster nutrient uptake than soil application and relatively less environmental pollution, foliar fertilization is more popular among plants. It can be seen that nanofertilizers and foliar fertilization are the hotspots of attention at present and that current research on the foliar application of nanofertilizers is not as extensive as that on soil application. Based on this background, this paper provides an overview of various applications of foliar spraying of nanofertilizers in agriculture, including applications in improving crop yield and quality as well as mitigating heavy metal stress, salt stress and drought stress. [ABSTRACT FROM AUTHOR]

Drought is the most important natural disaster affecting crop growth and development. Crop rhizosphere microorganisms can affect crop growth and development, enhance the effective utilization of nutrients, and resist adversity and hazards. In this paper, six spring wheat varieties were used as research material in the dry farming area of the western foot of the Greater Khingan Mountains, and two kinds of water control treatments were carried out: dry shed rain prevention (DT) and regulated water replenishment (CK). Phenotypic traits, including physiological and biochemical indices, drought resistance gene expression, soil enzyme activity, soil nutrient content, and the responses of potential functional bacteria and fungi under drought stress, were systematically analyzed. The results showed that compared with the control (CK), the leaf wilting, drooping, and yellowing of six spring wheat varieties were enhanced under drought (DT) treatment. The plant height, fresh weight (FW), dry weight (DW), net photosynthetic rate (Pn) and stomatal conductance (Gs), soil total nitrogen (TN), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP), organic carbon (SOC), and soil alkaline phosphatase (S-ALP) contents were significantly decreased, among which, FW, Gs and MBC decreased by more than 7.84%, 17.43% and 11.31%, respectively. By contrast, the soil total phosphorus (TP), total potassium (TK), and soil catalase (S-CAT) contents were significantly increased (p < 0.05). TaWdreb2 and TaBADHb genes were highly expressed in T.D40, T.L36, and T.L33 and were expressed at low levels in T.N2, T.B12, and T.F5. Among them, the relative expression of the TaWdreb2 gene in T.L36 was significantly increased by 2.683 times compared with CK. Soil TN and TP are the most sensitive to drought stress and can be used as the characteristic values of drought stress. Based on this, a drought-tolerant variety (T.L36) and a drought-sensitive variety (T.B12) were selected to further analyze the changes in rhizosphere microorganisms. Drought treatment and cultivar differences significantly affected the composition of the rhizosphere microbial community. Drought caused a decrease in the complexity of the rhizosphere microbial network, and the structure of bacteria was more complex than that of fungi. The Shannon index and network modular number of bacteria in these varieties (T.L36) increased, with rich small-world network properties. Actinobacteria, Chloroflexi, Firmicutes, Basidiomycota, and Ascomycota were the dominant bacteria under drought treatment. The beneficial bacteria Bacillus, Penicillium, and Blastococcus were enriched in the rhizosphere of T.L36. Brevibacillus and Glycomyce were enriched in the rhizosphere of T.B12. In general, drought can inhibit the growth and development of spring wheat, and spring wheat can resist drought hazards by regulating the expression of drought-related genes, regulating physiological metabolites, and enriching beneficial microorganisms. [ABSTRACT FROM AUTHOR]

Climate change is affecting all regions of the world with different climates, and the scale of damage is increasing due to the occurrence of various natural disasters. In particular, maize production is highly affected by abnormal climate events such as heat waves and droughts. Increasing temperatures can accelerate growth and shorten the growing season, potentially reducing productivity. Additionally, enhanced temperatures during the ripening period can accelerate the process, reducing crop yields. In addition, drought stress due to water deficit can greatly affect seedling formation, early plant growth, photosynthesis, reproductive growth, and yield, so proper water management is critical to maize growth. Maize, in particular, is tall and broad-leaved, so extreme drought stress at planting can cause leaves to curl and stunt growth. It is important to understand that severe drought can have a detrimental effect on the growth and reproduction of maize. In addition, high temperatures caused by drought stress can inhibit the induction of flowering in male flowers and cause factors that interfere with pollen development. It is therefore important to increase the productivity of all food crops, including maize, while maintaining them in the face of persistent drought caused by climate change. This requires a strategy to develop genetically modified crops and drought-tolerant maize that can effectively respond to climate change. The aim of this paper is to investigate the effects of climate change and drought tolerance on maize growth. We also reviewed molecular breeding techniques to develop drought-tolerant maize varieties in response to climate change. [ABSTRACT FROM AUTHOR]

Copyright of Folia Pomeranae Universitatis Technologiae Stetinensis Agricultura Alimentaria Piscaria et Zootechnica is the property of West Pomeranian University of Technology in Szczecin and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Legumes play a significant role in the alleviation of food insecurity, maintaining soil fertility, and achieving sustainable crop production under adverse environmental conditions. The increased demand in legume production contemplates that attention on the genetic improvement of these crops through various means such as genetic engineering and mutation breeding should take a centre stage in global agriculture. Therefore, this paper provides a succinct analysis of the currently available literature on morphological and physiological traits in polyploidised leguminous plants to counter the adverse effects of drought stress. The effects of colchicine on various morphological and physiological traits of polyploidised legumes compared to their diploid counterparts were examined. Numerous reports revealed variations in these traits, such as improved root and shoot growth, plant biomass, chloroplastidic content, protein, RNA, and DNA. The differences observed were also associated with the strong relationship between plant ploidy induction and colchicine application. Furthermore, the analysis indicated that polyploidisation remains dose-dependent and may be achievable within a shorter space of time as this antimitotic chemical interferes with chromosome separations in somatic plant cells. The efficiency of this process also depends on the advancement of treatment conditions (in vitro, in vivo, or ex vitro) and the successful regeneration of polyploidised plants for adaptation under drought stress conditions. As such, the improvement in metabolite profile and other essential growth characteristics serves as a clear indication that induced polyploidy needs to be further explored to confer resilience to environmental stress and improve crop yield under drought stress conditions in leguminous plants. [ABSTRACT FROM AUTHOR]

Purpose: Seed orientation is widely known to affect shoot growth, but the effects on root growth and crop drought tolerance are unclear. Thus, one germination paper experiment, two soil pot experiments and one field experiment were conducted to study the effects of seed orientation (Brush-up, Brush-down, Crease-up and Crease-down) on crop root and shoot growth under two water treatment levels (full and deficit) using winter wheat (Triticum aestivum L.) as an example. Methods: Seedling root traits, early shoot growth, mature root distribution, soil water consumption, root/shoot ratio, harvest index and grain yield were measured. Results: The results showed that under full irrigation, the control Brush-up orientation allowed for the highest grain production, mainly due to shoot growth. However, Crease-down resulted in the highest yield under limited-water supplies because root biomass was optimally related to grain yield in the pots, and a reasonably deep root system (lower root biomass and longer specific root length) benefitted yield production in the field. The higher shoot biomass, lower root/shoot ratio and higher harvest index also contributed to a higher grain yield under deficit irrigation, suggesting that sowing seeds lying flat with the crease down can optimize root and shoot growth and improve drought tolerance. Conclusions: To our knowledge, this is the first report verifying that seed orientation can significantly regulate root growth under dry conditions, providing a possible new mechanism underlying crop drought tolerance. [ABSTRACT FROM AUTHOR]

Global agricultural demand and the impact of fluctuating climatic conditions including global warming have catastrophically limited crop productivity and immensely outstretched the market value of agricultural products leading to acute inflation. The effect of desiccation or drought stress in plants is manifested at three levels viz. morphological, biochemical, and molecular and plants possess their own molecular and signaling arsenal to combat or ameliorate various stresses. For decades, stress-tolerant cultivars have been investigated and modulation of polyamine (PA) signaling was found to play a major role in attenuating environmental stresses including drought as major abiotic stress. PA metabolism pathways with their ability to crosstalk with both primary and secondary metabolic pathways have been correlated with several other responses such as seed germination, plant growth, development, defense, hormonal regulation, stress tolerance, and crop yield. Recent transcriptomic and metabolomic approaches have expanded the knowledge on the regulation of stress-induced biochemical, molecular, and physiological alterations. To fully comprehend the intricate biochemical network of plant stress physiology, it is necessary to identify exact responses against specific stress stimuli, interpret concurrent epigenetic alterations, and use molecular switching. The present review encompasses recent updates on drought tolerance mechanisms mediated by diverse polyamines playing significant roles in metabolic regulation, oxidative stress management, and systematic stress-reversal signaling. Besides, the drought stress-reversal role of polyamines and their cross-talks with other signaling molecules have also been documented. Gene, enzyme, and transcription factor (TF) functional features were retrieved from the published papers involving transgenic or mutant plants with over-expression or loss-of-function investigations. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSE) were simultaneously colonized in the root cells of maize. Single AMF and DSE symbiosis have been proven to improve the drought tolerance of maize. However, the effects of both fungi coexisting in maize roots under drought stress are not yet known. In this study, pot experiments of maize seedlings were conducted through four inoculation treatments (single AMF inoculation of Rhizophagus irregularis, single DSE inoculation of Exophiala pisciphila, co-inoculation of AMF + DSE and non-mycorrhizal inoculation) under well-watered (WW) and drought-stressed (DS) conditions. AMF and DSE colonization status, maize physiology and aquaporin gene expression in maize roots were investigated. The objective of this paper was to evaluate whether AMF and DSE had competitive, independent or synergistic effects on regulating the drought tolerance of maize. When maize seedlings of three inoculation treatments were subjected to drought stress, single AMF inoculation had the highest shoot and root dry weight, plant height, root length, osmotic root hydraulic conductivity and hydrostatic root hydraulic conductivity in maize seedlings. However, co-inoculation of AMF + DSE induced the highest stomatal conductance in maize leaves and the lowest H2O2 and O2•− concentration, membrane electrolyte leakage, intercellular CO2 concentration and gene expression level of ZmPIP1;1, ZmPIP1;2, ZmPIP2;1, ZmPIP2;5 and ZmPIP2;6. In addition, co-inoculation of AMF + DSE also obviously down-regulated the GintAQPF1 and GintAQPF2 expression in R. irregularis compared with single AMF inoculation treatment. Under DS stress, there were competitive relationships between AMF and DSE with regard to regulating mycorrhizal colonization, maize growth, root hydraulic conductivity and the gene expression of aquaporins in R. irregularis, but there were synergistic relationships with regard to regulating membrane electrolyte leakage, oxidative damage, photosynthesis and the aquaporin gene expression of maize seedlings. The obtained results improve our knowledge about how the mechanisms of AMF and DSE coexist, promoting the drought tolerance of host plants. [ABSTRACT FROM AUTHOR]

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[Objective) The present paper aimed to obtain the complete sequence of SsREMO-la gene, conduct tissue-specific expression, qPCR expression analysis, sub-cellular localization study, and the phenotypic changes of Arabidopsis thaliana with SsREMO-la gene transfer and the expression pattern of CAT-1 gene. (Method) The complete sequence of SsREMO-la gene was obtained by PCR, purification, cloning and sequencing from Hainan sugarcane wild species (Sp-24). Drought stress was applied to the normal growth of the seedlings. Young leaves, roots and stems at 0, 1, 2, 3, 4 and 5 days after the stress treatment were collected for tissue-specific expression analysis and qPCR analysis. The tissue location and function of SsREMO-1a were analyzed by tobacco sub-cellular mapping and gene transformation techniques. PB1221-SSREMO-1a-GFP fusion expression vector was constructed and transformed into tobacco for cell localization analysis. The over-ex- pression vector pCAMBIA 1304-SsREMO-la was constructed, and SsREMO-1a was introduced into A. thaliana by agrobacterium transformation. The phenotypes of plants at 0, 1, 2, 3, 4 and 5 days after drought stress and the expression of CAT-1 gene were observed. [Result] The full length of SsREMO-1a gene was 738 bp, and the open code frame (ORF) was 564 bp, encoding 187 amino acids. Tissue-specific expression showed that SsREMO-1a was expressed in roots, stems and leaves. qPCR results showed that the gene was induced by drought stress and showed significantly up-regulated expression. The results of sub-cellular localization showed that SsREMO-1a protein was localized on the cell membrane. A total of 11 transgenic A. thaliana lines were obtained, and the drought resistance identification showed that the transgenic plants could improve the drought resistance of the plants. The expression of CAT-1 gene in transgenic plants was significantly in- creased. [Conclusion] SsREMO-1a can improve the drought resistance of plants and regulate CAT-1 gene to some extent. [ABSTRACT FROM AUTHOR]

【Objective】The paper aims to explore the effect of drought stress on endogenous hormones in Camellia reticulata and the molecular mechanism of plant hormone signal transduction pathway responding to drought stress.【Method】The pot seedlings of half-one-year-old wild C.reticulata were used as experimental materials, and 20% PEG-6000 was used to simulate severe drought stress. The contents of auxin (IAA), zeatin nucleoside (ZR), gibberellin (GA) and abscisic acid (ABA) in roots and leaves of C.reticulata at 0, 24, 72 hours and 48 hours after rewater (re48 hours) under drought stress, and at the same time, the leaves were sequenced by transcriptome to screen differential genes.【Result】Under drought stress, the endogenous hormones in C.reticulata were all affected. The IAA content in leaves first increased and then decreased and then increased after rehydration, while the IAA content in roots continued to decrease and did not recover after rewater. The change trend of ZR content in leaves was the same as IAA, while that in roots was opposite to that in leaves.GA content in leaves increased continuously during stress and rewater, while GA content in roots increased during stress and decreased after rewater. The change trend of ABA content in leaves was similar to IAA, and ABA content in roots continued to increase during stress, and then decreased after rewater, which was similar to the change trend of GA content in roots.A total of 33 349 differentially expressed genes were screened from the transcriptome sequencing results of C.reticulata, which were significantly enriched in plant hormone transduction, phenylpropionic acid biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, photosynthesis and other pathways at four time points. Drought stress induced the expression of 46 differential genes in plant hormone signal transduction pathway. Four gene modules were identified by weighted gene co-expression network analysis (WGCNA), and the transcription group was correlated with the contents of the four hormones. Two key gene modules with high correlation with hormone response were screened, including 2769 and 2502 genes respectively. The top 5% genes in the key modules were selected for co-expression analysis, and six key genes (SDH1-1, PETC, VHA-A3, FtsH, chlD, TL17) and five transcription factors (IAA9, NAC, Trihelix, SWI/SNF, NF-YB) were obtained.【Conclusion】Drought stress affects the changes of endogenous hormone content and the expression of related pathway genes. In the study, two co-expression modules closely related to drought stress response are also identified. It is found that genes such as SDH1-1, PETC, VHA-A3, FtsH, chlD, TL17 and transcription factors such as IAA9, NAC, Trihelix, SWI/SNF, NF-YB play an important role in the response of endogenous hormones in C.reticulata under drought stress. [ABSTRACT FROM AUTHOR]

Bromus sterilis L. (barren brome) is one of the most economically important noxious grass weeds in the winter cereal fields of Europe. Its ecological behaviour in this agro-climatic region should be assessed for effective weed control strategies. The present study was conducted to assess the dormancy and germination response of the B. sterilis population from the Czech Republic under thermal, light, and stress conditions. The dormancy loss experiment revealed that seeds exposed to the light regime showed a remarkably lower percentage of germination, and under alternating temperatures of 10/20 °C in dark conditions, rapid loss of primary dormancy was observed. This population was found to germinate across a wide temperature range of 5-35 °C, with the highest germination rate at 25 °C (T50 = 1.14 days in dark, 1.21 days in light) and the germination time increased with decreasing temperatures below 25 °C. Further, due to fitness advantage, herbicide-resistant (R) biotypes were found to be more stress-tolerant than susceptible (S) biotypes under salinity and drought conditions. In the highest stress conditions, the germination of S biotypes was negligible, while R biotypes can germinate under high stress, but germination decreased below 25 °C. The current findings may add value to effective weed control strategies using prediction models based on seed dormancy and germination values under different hydrothermal conditions. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effect of traffic stress by soil compaction on zoysiagrass by analyzing the aerial and underground parts and hyperspectral analysis. Zoysiagrass plants were subjected to a compaction strength gradient from 35 to 80 kgf/cm² to confirm the compaction resistance and recoverable limit and measure the physiological change during stress. Changes in leaf color, photosynthesis, and hyperspectral reflectance due to continuous weak and strong traffic stress were measured, and vegetation indices were evaluated for the critical traffic stress injury assessment. As a result, the stem of the zoysiagrass was severely damaged up to 70 kgf/cm² based on soil hardness. The recoverable limit strength of soil compaction was 55 kgf/cm² under weak response pressure conditions. Collectively, our results show that the damage of weak compaction strength on the zoysiagrass was quickly recovered after the stop of traffic stress, especially since the growth of the underground part was increased by weak traffic stress. However, if the compaction strength above 65 kgf/cm² lasted for a long time, the growth of the underground part is limited by lowering the energy supply for the recovery occurred, in turn, the recovery occurred slowly after the compaction was stopped. Among the vegetation indices obtained from hyperspectral data, pigment specific simple ratio for chlorophyll a (PSSRa), pigment specific simple ratio for chlorophyll b (PSSRb), and pigment specific simple ratio for carotenoids (PSSRc) were effective in evaluating the damage of traffic stress. [ABSTRACT FROM AUTHOR]

The Pentatricopeptide repeat (PPR) superfamily is a large gene family in plants that regulates organelle RNA metabolism, which is important for plant growth and development. However, a genome-wide analysis of the PPR gene family and its response to abiotic stress has not been reported for the relict woody plant Liriodendron chinense. In this paper, we identified 650 PPR genes from the L. chinense genome. A phylogenetic analysis showed that the LcPPR genes could roughly be divided into the P and PLS subfamilies. We found that 598 LcPPR genes were widely distributed across 19 chromosomes. An intraspecies synteny analysis indicated that duplicated genes from segmental duplication contributed to the expansion of the LcPPR gene family in the L. chinense genome. In addition, we verified the relative expression of Lchi03277, Lchi06624, Lchi18566, and Lchi23489 in the roots, stems, and leaves and found that all four genes had the highest expression in the leaves. By simulating a drought treatment and quantitative reverse transcription PCR (qRT-PCR) analysis, we confirmed the drought-responsive transcriptional changes in four LcPPR genes, two of which responded to drought stress independent of endogenous ABA biosynthesis. Thus, our study provides a comprehensive analysis of the L. chinense PPR gene family. It contributes to research into their roles in this valuable tree species' growth, development, and stress resistance. [ABSTRACT FROM AUTHOR]

Key message: This paper sheds light on the evolution and expression patterns of MADS genes in Setaria and Panicum virgatum. SiMADS51 and SiMADS64 maybe involved in the ABA-dependent pathway of drought response. The MADS gene family is a key regulatory factor family that controls growth, reproduction, and response to abiotic stress in plants. However, the molecular evolution of this family is rarely reported. Here, a total of 265 MADS genes were identified in Setaria italica (foxtail millet), Setaria viridis (green millet), and Panicum virgatum (switchgrass) and analyzed by bioinformatics, including physicochemical characteristics, subcellular localization, chromosomal position and duplicate, motif distribution, genetic structure, genetic evolvement, and expression patterns. Phylogenetic analysis was used to categorize these genes into M and MIKC types. The distribution of motifs and gene structure were similar for the corresponding types. According to a collinearity study, the MADS genes have been mostly conserved during evolution. The principal cause of their expansion is segmental duplication. However, the MADS gene family tends to shrink in foxtail millet, green millet, and switchgrass. The MADS genes were subjected to purifying selection, but several positive selection sites were also identified in three species. And most of the promoters of MADS genes contain cis-elements related to stress and hormonal response. RNA-seq and quantitative Real-time PCR (qRT-PCR) analysis also were examined. SiMADS genes expression levels are considerably changed in reaction to various treatments, following qRT-PCR analysis. This sheds fresh light on the evolution and expansion of the MADS family in foxtail millet, green millet, and switchgrass, and lays the foundation for further research on their functions. [ABSTRACT FROM AUTHOR]

Introduction: Soil microbial communities are key to functional processes in terrestrial ecosystems, and they serve as an important indicator of grasslands status. However, the responses of soil microbial communities and functional potential to drought stress in semiarid alpine grasslands remain unclear. Methods: Here, a field experiment was conducted under ambient precipitation as a control, -20% and -40% of precipitation to explore the responses of soil microbial diversity, community composition, and predicted functional potential to drought stress in a semiarid alpine grassland located in the northwest of China. Moreover, 16S rRNA gene and ITS sequencing were used to detect bacterial and fungal communities, and the PICRUST and FUNGuild databases were used to predict bacterial and fungal functional groups. Results: Results showed drought stress substantially changes the community diversity of bacteria and fungi, among which the bacteria community is more sensitive to drought stress than fungi, indicating that the diversity or structure of soil bacteria community could serve as an indicator of alpine grasslands status. However, the fungal community still has difficulty maintaining resistance under excessive drought stress. Our paper also highlighted that soil moisture content, plant diversity (Shannon Wiener, Pieiou, and Simpson), and soil organic matter are the main drivers affecting soil bacterial and fungal community composition and predicted functional potential. Notably, the soil microbial functional potential could be predictable through taxonomic community profiles. Conclusions: Our research provides insight for exploring the mechanisms of microbial community composition and functional response to climate change (longer drought) in a semiarid alpine grassland. [ABSTRACT FROM AUTHOR]

This paper aims to compare the effect of different soil configurations on plant growth under long-term drought to provide a theoretical basis for soil reclamation and vegetation restoration in the contiguous area between Shanxi, Shaanxi, and Inner Mongolia, China. With the widely distributed montmorillonite-enriched sandstone in this area as the soil structure ameliorator and the sandy soil as the test soil, indoor simulation and soil column tests were conducted to study the water holding capabilities of different reconstructed soils configurations. The drought stress test of alfalfa on these soils explored the correlation between the growth of alfalfa and soil water in various configurations. The soil–water characteristic curve and soil texture were analyzed to determine plant survival. The results showed that the addition of montmorillonite-enriched sandstone with high water holding capacity and water diffusion rates could increase the water content of the sandy soil. The treatments with 20 and 30 cm montmorillonite-enriched sandstone at the depths of 20–40 cm and 20–50 cm demonstrated the longest survival time (60 days and 59 days), the highest germination (34% and 35%), and the highest water holding capacity (22.6% and 27.3%), indicating that soils with higher water holding capacity and lower diffusion rates could be used as a reservoir, in combination with other soil materials with high water content, and that the addition of the montmorillonite-enriched sandstone layer at 20–30 cm in the sandy soil is the optimal choice for topsoil reclamation in open-mining areas. [ABSTRACT FROM AUTHOR]

In this paper, the author discusses the effects of drought stress on pearl millet genotypes during the vegetative stage of development and the plant's mechanisms for survivability under stress with various nitrogen treatment regimes. A total of six treatment conditions were imposed on plants, i.e., N0 (no Nitrogen-0 mM), N0+PEG-10%, LN (low Nitrogen-2.5 mM), LN+PEG-10%, HN (high Nitrogen-7.0 mM), and HN+PEG-10%. Five days of moderate drought stress caused significant morphophysiological changes, as evidenced by a reduction in fresh and dry biomass, as well as relative water content (RWC), relative electrolyte leakage, and chlorophyll fluorescence,. A significant reduction in plant biomass and RWC when compared to the controls was seen. Reactive oxygen species (ROS) and lipid peroxidation (MDA) levels increased in the shoot in response to drought stress along with a loss of membrane integrity. A nitrogen treatment regime regulated the drought stress. In relation to N0-treated batches, proline accumulation increased in various N-treated batches. Results revealed that GHB-538 is less tolerant to drought stress in different N treatment conditions, while RHB-234 and 223 showed better tolerance to drought under nitrogen treatments. The significance of this study is to uncover the regulatory role of nitrogen over the drought stress in pearl millet. [ABSTRACT FROM AUTHOR]

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Bacterial endophytes present within plant tissues play an important role in maintaining host plant fitness, nutrient supply and mainly to mitigate water deficit stress. In this investigation, it was hypothesized that bacterial endophytes inhabiting the tissues of drought tolerant plants would ameliorate drought stress in maize seed germination. In this study 54 bacterial endophytes were isolated from drought adopted plants collected across different drought prone areas of Karnataka. These endophytes were screened for Osmotolerance using Polyethylene glycol (PEG MW-8000) at 15 and 20 per cent. Out of 54 isolates, five bacterial isolates (P7L1, P2L2, P6R1, P3L2 and P7R1) showed growth in the presence of 20 per cent PEG. These five bacterial isolates were inoculated to pre-germinated maize seeds and incubated in paper towel dipped with 15 per cent PEG. All the five endophytes inoculated seedlings showed increased growth of maize seedlings compared to un-inoculated seedling. However, the P7L1 isolate inoculated seedlings showed significantly increased seedling length than other isolates inoculated seedlings indicating its efficiency against water deficit stress This bacterium isolate was identified as Pseudomonas tolaasii using 16S rRNA gene sequence and its presence in the inoculated seedling was confirmed by re-isolation of bacterium after 10 days of seedling growth and comparing culture with inoculated mother culture both morphologically as well as by 16Sr RNA. [ABSTRACT FROM AUTHOR]

Background: The behavior of Abscisic acid (ABA) as a stress phytohormone may be involved in mechanisms leading to tolerance and survival in adverse environmental conditions such as drought stress. Methods: Here, we evaluated ABA-mediated responses at physio-biochemical and molecular levels in drought-stressed seedlings of two different Desi-type chickpea genotypes (10 as a tolerant genotype and 247 as a sensitive one). Results: Under drought stress, two chickpea genotypes showed a decrease in their relative water content (RWC), and the intense decrease was related to the sensitive genotype (73.9%) in severe stress. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) concomitant with the severity of stress increased in genotypes and the higher increase was in the sensitive genotype (5.8-fold and 3.43-fold, respectively). In the tolerant genotype, the enhanced accumulation of total phenolic content (1.75-fold) and radical scavenging action, based on 1,1-diphenyl-2-picrylhydrazyl test (DPPH), (1.69-fold) were simultaneous with ABA accumulation (1.53-fold). In the tolerant genotype, transcriptional analysis presented upregulation of Zeaxanthin epoxidase (ZEP) (1.35-fold), 9-cis-epoxycarotenoid dioxygenase (NCED) (5.16-fold), and Abscisic aldehyde oxidase (AAO) (1.52-fold compared to control conditions) genes in severe stress in comparison with mild stress. The sensitive genotype had a declining trend in total chlorophyll (up to 70%) and carotenoid contents (36%). The main conclusion to be drawn from this investigation is that ABA with its regulatory effects can affect drought tolerance mechanisms to alleviate adverse effects of unsatisfactory environmental conditions. Conclusions: In this paper, we tried to indicate that drought stress induces overexpression of genes triggering ABA-mediated drought responses simultaneously in two genotypes while more increment expression was related to the tolerant genotype. At first thought, it seems that the tolerant genotype compared to the sensitive genotype has a genetically inherent ability to cope with and drop adverse effects of drought stress through over-accumulation of ABA as drought. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to analyze the impact of varying degrees of drought stress treatments on the physiological parameters of Indigofera pseudotinctoria, preliminarily evaluate the drought-resistant physiological responses of these materials, and provide a foundational reference for the selection and genetic improvement of drought-resistant germplasm in I. pseudotinctoria. [Method] 36 wild J. pseudotinctoria germplasm resources collected in Chongqing area were used as experimental materials. Pot cultivation was used to start drought treatment when 1. pseudotinctoria seedlings grew to the 90th day, and measure the content of osmoregulatory substances, relative water content, and antioxidant enzyme activity in the leaves of I. pseudotinctoria under 0 days of stress (control group CK, the relative soil water content was 80%-85% of the field water capacity), 7 days of stress (moderate drought, soil relative moisture content was 40%-50% of the field water capacity), and 14 days of stress (severe drought, soil relative moisture content was 20%-25% of the field water capacity). Drought resistance coefficients, membership functions and cluster analysis were applied for a comprehensive evaluation of drought resistance. [Result] Under drought stress conditions, we observed a wide variation in physiological responses among the 36 1. pseudotinctoria germplasms, leading to significant differences in their drought resistance capabilities. Comparative analysis of mean values for various parameters showed that, in comparison to the control group, osmotic adjustment substances such as malondialdehyde (MDA), soluble protein (SP), and proline (Pro) increased with the severity of drought. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) exhibited a convex trend as drought severity intensified, while relative water content (RWC) decreased with increasing drought stress. Among the seven parameters measured, peroxidase (POD) activity showed the largest coefficient of variation, while relative water content (RWC) displayed the smallest variation. Using membership function analysis, comprehensive D-value assessment, and cluster analysis, we categorized the drought resistance of the 36 1. pseudotinctoria germplasms into two distinct groups: Drought-resistant (comprising 8 germplasms) and sensitive (comprising 28 germplasms). Further examination of physiological indicators between these two groups revealed that drought-resistant germplasms exhibited higher antioxidant enzyme activity and osmotic adjustment substance Pro content compared to their sensitive counterparts. Conclusion] Under drought stress conditions, the physiological responses of the 36 1. pseudotinctoria germplasm resources displayed significant diversity and variation. Among the 36 1. pseudotinctoria germplasms, 8 germplasms were classified as drought-resistance by a comprehensive evaluation analysis. [ABSTRACT FROM AUTHOR]

Key message: PtrANR1 positively regulates plant drought tolerance by increasing proline level and reducing ROS accumulation. PtrANR1 directly activates PtrAUX1 expression to promote root growth and improve plant drought tolerance. Citrus quality and yield are severely declined under drought stress. To date, the effects of MADS-box family transcription factors (TFs) on plant drought resistance have made some progress. However, whether MADS-box family TFs are associated with citrus drought response has remained unclear. The current paper identified a MADS-box family gene PtrANR1 encoding anthocyanidin reductase from trifoliate orange. PtrANR1 exhibits high identities with ANR1 proteins found in various plants. PtrANR1 possesses two conserved domains known as MADS and kertanin-like domains. PtrANR1 is a nuclear protein which has transactivation activity. A significant induction of PtrANR1 transcript was detected in leaves and roots of trifoliate orange treated with PEG6000 and ABA. Under drought stress, Arabidopsis ectopic overexpressing PtrANR1 exhibited obviously elevated contents of proline, ABA and IAA, better developed root, enhanced antioxidant enzyme activities, as well as notably reduced accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS) compared with WT plants. However, opposite change trends of these physiological indices were detected in PtrANR1 homolog silencing lemon. Furthermore, transgenic Arabidopsis displayed significantly increased expression levels in genes associated with ABA, IAA and proline production, IAA polar transport, ROS elimination and drought response. However, these genes exhibited noticeably decreased transcript levels in PtrANR1 homolog silencing lemon. Moreover, PtrANR1 could increase IAA content and promote root growth by binding to GArG-box in the promoter of PtrAUX1 to activate its transcript. These findings indicated that PtrANR1 had a beneficial impact on plant drought resistance through promoting root development, increasing proline accumulation and scavenging of ROS. [ABSTRACT FROM AUTHOR]

The root system is vital for anchorage, mobilizing water and nutrients and symbiosis with soil microbes, which influence adaptation and crop performance. However, root traits are not widely used in crop variety development because root phenotyping is difficult and there is limited understanding of the genetics of root traits. The available genetic variation and emerging root phenotyping and genotyping technologies present opportunities for integrating root traits in breeding. Selection efficiency for root traits can be enhanced by integrating shovelomics, digital imaging, crop modelling and gene sequencing systems. Therefore, the objectives of this review are to discuss critical root traits and their vital functions, genetic variation present for root traits, opportunities and challenges in root phenotyping and integration of genomic tools in breeding for improved root systems. The information presented in the paper will guide crop breeders in developing a new generation of crop varieties with desirable yield and root traits. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper highlights the evolution and impact of the SWAP model (Soil – Water – Atmosphere – Plant), which was initiated by R.A. Feddes and colleagues fifty years ago, in 1974. Since then, the SWAP model has played a crucial role in the advancement of agrohydrology. This paper highlights some major advances that have been made, especially focussing on the last fifteen years. The domain of the SWAP model deals with the simulation of the soil water balance in both unsaturated and saturated conditions. The model solves the Richards equation using the water retention and hydraulic conductivity functions as described by the Van Genuchten – Mualem equations. Bimodal extensions of the Van Genuchten - Mualem relationships have been implemented, as well as modifications near saturation and addressing hysteresis. An important sink term in the Richards equation is root water uptake. Crop development plays an important role in a robust simulation of root water uptake. That is why a link has been made with the dynamic crop growth model WOFOST. Instead of using a prescribed crop development, a distinction between potential and actual crop development is calculated by reducing the potential photosynthesis as a result of water or oxygen stress. Since the early days of SWAP, empirical and macroscopic concepts have been used to simulate root water uptake. Recently two process-based concepts of root water uptake and oxygen stress have also been implemented. Another important sink-source term in the Richards equation is the interaction with artificial drains. In SWAP, drainage can be simulated by either using prescribed or simulated drain heads and simulation of controlled drainage with subirrigation is possible. Finally, we briefly elaborate on three studies using SWAP: water stresses in agriculture in the Netherlands, regional water productivity in China, and controlled drainage with subirrigation. We finish discussing promising developments for the near future.

The paper is dealing with the effects of the late drought stress on the productivity and yield components of 12 varieties and 7 lines of winter bread wheat, which differ in morphophysiological characteristics. It was found that drought stress created in the late period decreased productivity, number of spikes per sheaf, number of spikelets per spike, number and mass of grains per spike and mass of 1000 grains by 19.9%, 7.7%, 4.9%, 12.8%, 21,6%, and 10.01%, respectively. As can be seen, of the components directly affected by water stress, the productivity and grain mass per spike were the most depressed, while number of spikes per unit area and number of spikelets per spike was relatively stable. Under late drought stress, Gobustan and Gyrmyzy gul 1 varieties, 7thWON-SA No.465 and Ferrigineum 2/19 lines manifested the highest productivity (557, 515, 607, and 549 g/m², respectively). Under drought stress, the most depressed values for 1000-grain mass were found for the genotypes Tale 38, Gyrmyzy gul 1, 12thIWWYT No.8, and Ferrigineum 2/19, while the least depressed values were found for Sonmez 01, Gobustan, 4thFEFWSN No.50 and 7thWON-SA No.477. [ABSTRACT FROM AUTHOR]

The plant is an important component of the riparian ecosystem, which could reflect both the environmental and functional characteristics of the riparian zone. Studies on species composition, diversity, community structure, distribution pattern, and adaptation strategies of plant communities in the riparian zone of the Three Gorges Reservoir (TGR) will help to explore the maintaining mechanism of the plant communities' ecological function under severe water-level fluctuation. The paper reviewed the plant community characteristics, functional traits as well as their eco-physiological responses and environmental adaptations in this special ecological zone. Based on this, future research orientations in this field were also prospected, which may focus on the maintenance mechanism of the plant community, suitable plants selection and their adaptation mechanism, the relationship between plant functional traits and ecosystem functions, plant niche in the riparian zone, and the connectivity of riparian zone to the surrounding environment. The results can promote the correlational research on plant communities in the riparian zone and deepen the understanding of ecosystem services the riparian ecotone provides. [ABSTRACT FROM AUTHOR]

Many studies have shown that abiotic stresses could severely impact crop growth and yield, but a comprehensive review from a bibliometric perspective is lacking. This study explores how the research direction of rice under drought, waterlogging or both stresses has evolved over the past three decades, based on bibliometric analysis using Vosviewer 1.6.15 and HistCite Pro. Data were collected from the academic database of Web of Science. The results showed that 12 journals had a high number of publications and highly local citations. Meanwhile, the three journals of Field Crops Research, Journal of Experimental Botany and Plant Physiology could be the most influential leaders in this field. The author Arvind Kumar had the highest contribution to the output of articles, and Lizhong Xiong had a greater impact on the field. China, and Chinese institutions, were dominant in terms of the number of articles, but Japan, Germany, UK and institutions in USA and Japan had a higher quality of publications on average. Scholars are concerned with using transgenic methods for improving rice productivity with increasing abiotic stress tolerance; the research topics of rice cultivars, irrigation, water-use efficiency and soil fertility may be gradually shifting from a single theme to intertwining with the themes of genomics and abiotic/biotic resistance with climate change in the future. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)