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The present experiment was conducted during winter (rabi) seasons of 2019–20 and 2020–21 at the ICAR-Indian Grassland and Fodder Research Institute, Jhansi, Uttar Pradesh to study the genetic diversity amongst oat (Avena sativa L.) lines for micronutrients and agro-morphological traits. For study, 150 oat accessions collected from different sources were evaluated for two years and four micronutrients (Zn, Cu, Fe and Mn) and 9 agro-morphological traits were recorded. Genotypes IG02122 (464.0 mg/kg), IG02156 (48.1 mg/kg), IG03271 (136.0 mg/kg), and IG03213 (22.0 mg/kg) had maximum Fe, Zn, Mn and Cu content in fodder (harvested at 50% flowering). Genotype IG0280 had both high Zn (36.97 mg/kg) and Mn (114.33 mg/kg); IG03233 had high Cu (18.0 mg/kg) and Mn (124.0 mg/kg); and IG02131 had high Cu (18.33 mg/kg) and Fe (369.0 mg/kg) content. Analysis of variance (ANOVA) highlighted significant genotypic differences (P

Photosynthesis is crucial for sustaining life on this planet and necessary for plant growth and development. Abiotic stresses such as high and low temperatures, and excess, or deficit of water limit the crucial plant processes, thus threatening the global food security. However, recent molecular approaches allowed elucidation of the photosynthetic components/compounds and their efficiency under stress conditions. In the present scenario, these approaches are not enough to reduce the yield penalty due to the reduction in photosynthetic efficiency. Therefore, comprehensive data on plant behavior and stress crosstalk networks could assist in understanding the in-depth mechanism of photosynthesis. In recent years, information regarding crosstalk, signaling characterization of candidate genes, and responses to multiple stressors have advanced our knowledge to understand the mechanism of photosynthesis. Therefore, in this review, we provide a comprehensive overview of various studies conducted on photosynthesis under multiple abiotic stress factors that affect the photosynthetic efficiency of a plant. We also discuss the role of crosstalk signaling compounds (plant growth regulators and micro RNAs) for an in-depth understanding of the photosynthesis mechanism. Finally, based on our gathered data set, the mechanism of damage and adaptive response of photosynthesis under multiple stressors are explained to enhance the scientific community's knowledge toward boosting photosynthesis and to accelerate stress tolerance strategies for crop improvement.

Global crop production is facing a myriad of challenges and obstacles to achieving food security in the near future. Among all the challenges, heat stress (HS) is one of them. In HS, the temperature is a prime factor responsible for affecting the optimum growth of plants. Higher temperatures lead to changes in plants' functional processes and negatively affect plant productivity. In most plants, the reproductive stage is the sensible one and is greatly hampered by HS. However, some of the mechanisms were developed to mitigate the drastic impacts of HS. Although, there is a massive gap in achieving the sustainability goal under the climate change scenario. By considering these facts, the present analysis deals with the impact of HS on vital processes such as water and nutritional status, assimilate partitioning, photosynthetic activity, yield, and oxidative damages. This review further discussed the molecular mechanisms of heat shock proteins (HSPs) including sHSPs, HSP60, HSP70, HSP90, and HSP100 in HS tolerance. This review also highlights the advanced molecular techniques such as genome editing, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), and omics that open exciting avenues in several directions related to heat stress tolerance mechanisms. Further, this gathered information helps in the understanding of recent advances in HS tolerance through HSPs, which could used in developing future strategies for warming temperatures. Moreover, this information supports the crop breeding program for developing high-temperature tolerant lines.

Nitrogen is a vital nutrient for agricultural, and a defieciency of it causes stagnate cotton growth and yield penalty. Farmers rely heavily on N over-application to boost cotton output, which can result in decreased lint yield, quality, and N use efficiency (NUE). Therefore, improving NUE in cotton is most crucial for reducing environmental nitrate pollution and increasing farm profitability. Well-defined management practices, such as the type of sources, N-rate, application time, application method, crop growth stages, and genotypes, have a notable impact on NUE. Different N formulations, such as slow and controlled released fertilizers, have been shown to improve N uptake and, NUE. Increasing N rates are said to boost cotton yield, although high rates may potentially impair the yield depending on the soil and environmental conditions. This study comprehensively reviews various factors including agronomic and environmental constraints that influence N uptake, transport, accumulation, and ultimately NUE in cotton. Furthermore, we explore several agronomic and molecular approaches to enhance efficiency for better N uptake and utilization in cotton. Finally, this objective of this review to highlight a comprehensive view on enhancement of NUE in cotton and could be useful for understanding the physiological, biochemical and molecular mechanism of N in cotton.

The impact of elevated temperature at the reproductive stage of a crop is one of the critical limitations that influence crop growth and productivity globally. This study was aimed to reveal how sowing time and changing field temperature influence on the regulation of oxidative stress indicators, antioxidant enzymes activity, soluble sugars (SS), and amino acids (AA) in Indian Mustard. The current study was carried out during the rabi 2017–2018 and 2018–2019 where, five varieties of mustard viz. Pusa Mustard 25 (PM-25) (V1), PM-26 (V2), BPR-541-4 (V3), RH-406 (V4), and Urvashi (V5) were grown under the field conditions on October 30 (normal sowing; S1), November 18 (late sowing; S2) and November 30 (very late sowing; S3) situations. The S1 and S3 plants, at mid-flowering stage, showed a significant variation in accumulation of SS (8.5 and 17.3%), free AA (235.4 and 224.6%), and proline content (118.1 and 133%), respectively, and played a crucial role in the osmotic adjustment under stress. The results showed that S3 sowing, exhibited a significant induction of the hydrogen peroxide (H2O2) (110.2 and 86.6%) and malondialdehyde (23.5 and 47.5%) concentrations, respectively, which indicated the sign of oxidative stress in plants. Interestingly, the polyphenol oxidase, peroxidase, superoxide dismutase, and catalase enzyme activities were also significantly increased in S3 plants compared to S1 plants, indicating their significant roles in ameliorating the oxidative stress. Furthermore, the concentration of fatty acid levels such as palmitic, stearic, oleic, and linoleic acids level also significantly increased in S3 plants, which influenced the seed and oil quality. The study suggests that the late sowing significantly impaired the biochemical mechanisms in Indian mustard. Further, the mustard variety V4 (RH-406) was found to be effective for cultivation as well as environmental stress adoption in Indian soils, and it could be highly useful in breeding for developing heat-tolerant genotypes for ensuring the food security.

The efficiency with which plants use nutrients to create biomass and/or grain is determined by the interaction of environmental and plant intrinsic factors. The major macronutrients, especially nitrogen (N), limit plant growth and development (1.5–2% of dry biomass) and have a direct impact on global food supply, fertilizer demand, and concern with environmental health. In the present time, the global consumption of N fertilizer is nearly 120 MT (million tons), and the N efficiency ranges from 25 to 50% of applied N. The dynamic range of ideal internal N concentrations is extremely large, necessitating stringent management to ensure that its requirements are met across various categories of developmental and environmental situations. Furthermore, approximately 60 percent of arable land is mineral deficient and/or mineral toxic around the world. The use of chemical fertilizers adds to the cost of production for the farmers and also increases environmental pollution. Therefore, the present study focused on the advancement in fertilizer approaches, comprising the use of biochar, zeolite, and customized nano and bio-fertilizers which had shown to be effective in improving nitrogen use efficiency (NUE) with lower soil degradation. Consequently, adopting precision farming, crop modeling, and the use of remote sensing technologies such as chlorophyll meters, leaf color charts, etc. assist in reducing the application of N fertilizer. This study also discussed the role of crucial plant attributes such as root structure architecture in improving the uptake and transport of N efficiency. The crosstalk of N with other soil nutrients plays a crucial role in nutrient homeostasis, which is also discussed thoroughly in this analysis. At the end, this review highlights the more efficient and accurate molecular strategies and techniques such as N transporters, transgenes, and omics, which are opening up intriguing possibilities for the detailed investigation of the molecular components that contribute to nitrogen utilization efficiency, thus expanding our knowledge of plant nutrition for future global food security.

Field crops are subjected to drought at different growth stages and cause for substantial yield loss in major crops, thus threaten to global food security. The crop researcher have evaluated numerous physiological, biochemical and molecular strategies to combat drought stresses but these approaches are not enough in present scenario. Therefore, it is argued that plants can be primed by assorted organic and in-organic promoters for excelling fortitude under stress conditions. Hence, seed priming with different agents is an auspicious area of research in stress biology and crop stress management, for conferring tolerance when plants are subjected to drought stress. However, the adaptation and tolerance mechanisms of drought stress are complex and quantitative in nature, which have been explored at physiological, biochemical and molecular levels thoroughly in this review. The concept of stress memory and its implication in future generation has also been discussed. Finally, in this review the challenges and opportunities of seed priming with effective application in crop stress management along with expanding the knowledge on deep understanding of drought stress tolerance to reduce the future yield gap are discussed thoroughly.

Seed priming technique has a marvelous potential in enhancing seed germination and crop establishment under limited soil moisture conditions, which ultimately increases yield. Therefore, we investigated the effects of seed priming on physiology, growth, yield and antioxidant defense system of pearl millet (Pennisetum glaucum L.) under rain-fed condition. The experiments were conducted under laboratory as well as field conditions comprising three treatments i.e., non-primed seeds (control, T0), priming with tap water (hydropriming) (T1) and priming with 2% KNO3 2% for 6 hours at 25°C followed by shade drying (T2). The results showed that chlorophyll content (10.37–14.15%) and relative water content (RWC) (12.70–13.01%) increased whereas proline (-19.44 to -25%) and soluble sugar (-15.51 to -29.13%) contents decreased on account of seed priming in pearl millet under field conditions. The seed priming significantly improved the plant height, final plant stand and grain weight which resulted in increased yield. Enhanced activities of superoxide dismutase (SOD) (5.89 to 8.10 unit/g/seed/min), catalase (CAT) (22.54 to 39.67 µmol/min/g/seed) and ascorbate peroxidase (APX) (8.92 to 22.10 µmol/cm/min/g) and concomitant decrease in H2O2 and malondialdehyde (MDA) content suggests their role in imparting oxidative tolerance at initial stages of growth in primed seed. The lab studies suggest that the improved yield might be attributes to increased seed germination and seedling vigor. It is recommended that the hydropriming (tap water) or KNO3 (2%) priming of seeds for 6 hours under ambient conditions is effective to enhance growth and yield of pearl millet under rainfed conditions.

Wheat is a widely grown cereal crop that provides >20% daily protein intake and calories worldwide. Drought stress drastically affects the crucial physiological (relative water content; RWC), biochemical (proline content), and molecular attributes in wheat plants from germination to maturity stage and ultimately reduces the yield and quality traits. Given this, the present work was conducted to know the effect of salt seed priming on wheat crop. For this, we have used two wheat variety HUW-468 (V1), and HUW-510 (V2) primed with water (T2), Mg(NO3)2 (T3), ZnSO4 (T4), and combinations of Mg(NO3)2 and ZnSO4 salt (T5) with non-primed seed (T1) under water stress (W1) and control (W0) conditions. We have observed significant differences in plant height (84 to 90 cm), leaf number, total leaf area (431.82 to 505.46 cm2 plant−1), relative water content, chlorophyll content (4.78 to 5.86 mg g−1fresh weight), membrane stability index (MSI) (56.25 to 61.42%), superoxide dismutase (SOD) activity (133.47 to 150.10), MDA content, proline content (101.64 to 100.46), nitrate reductase activity (NRA), and nutrient (N, Zn, and Fe) contents under control and stress conditions. These results concluded that seed priming with a combination of Mg(NO3)2 and ZnSO4 salt is best for improved wheat crop traits under drought stress compared to individual salt and non-priming treatments. Overall, this analysis elucidated that seed priming strengthens the antioxidant capacity under drought conditions by enhancing antioxidant enzymes and alleviating oxidative stress.

Plant growth regulators are naturally biosynthesized chemicals in plants that influence physiological processes. Their synthetic analogous trigger numerous biochemical and physiological processes involved in the growth and development of plants. Nowadays, due to changing climatic scenario, numerous biotic and abiotic stresses hamper seed germination, seedling growth, and plant development leading to a decline in biological and economic yields. However, plant growth regulators (PGRs) can potentially play a fundamental role in regulating plant responses to various abiotic stresses and hence, contribute to plant adaptation under adverse environments. The major effects of abiotic stresses are growth and yield disturbance, and both these effects are directly overseen by the PGRs. Different types of PGRs such as abscisic acid (ABA), salicylic acid (SA), ethylene (ET), and jasmonates (JAs) are connected to boosting the response of plants to multiple stresses. In contrast, PGRs including cytokinins (CKs), gibberellins (GAs), auxin, and relatively novel PGRs such as strigolactones (SLs), and brassinosteroids (BRs) are involved in plant growth and development under normal and stressful environmental conditions. Besides, polyamines and nitric oxide (NO), although not considered as phytohormones, have been included in the current review due to their involvement in the regulation of several plant processes and stress responses. These PGRs are crucial for regulating stress adaptation through the modulates physiological, biochemical, and molecular processes and activation of the defense system, upregulating of transcript levels, transcription factors, metabolism genes, and stress proteins at cellular levels. The current review presents an acumen of the recent progress made on different PGRs to improve plant tolerance to abiotic stress such as heat, drought, salinity, and flood. Moreover, it highlights the research gaps on underlying mechanisms of PGRs biosynthesis under stressed conditions and their potential roles in imparting tolerance against adverse effects of suboptimal growth conditions.

Abiotic stressors are major constraints that affect agricultural plant physio-morphological and biochemical attributes, resulting in a loss of normal functioning and, eventually, a severe decline in crop productivity. The co-occurrence of different abiotic stresses, rather than a specific stress situation, can alter or trigger a wide range of plant responses, such as altered metabolism, stunted growth, and restricted development. Therefore, systematic and rigorous studies are pivotal for understanding the impact of concurrent abiotic stress conditions on crop productivity. In doing so, this review emphasizes the implications and potential mechanisms for controlling/managing combined abiotic stresses, which can then be utilized to identify genotypes with combined stress tolerance. Furthermore, this review focuses on recent biotechnological approaches in deciphering combined stress tolerance in plants. As a result, agronomists, breeders, molecular biologists, and field pathologists will benefit from this literature in assessing the impact of interactions between combined abiotic stresses on crop performance and development of tolerant/resistant cultivars.