Publications of NIPGR Scientists
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Item Exploring the synergistic effects of drought and heat stress on chickpea seed development: Insights into nutritional quality and seed yield(Elsevier B.V., 2024) Awasthi, Rashmi; Devi, Poonam; Jha, Uday Chand; Sharma, Kamal Dev; Roorkiwal, Manish; Kumar, Sanjeev; Pareek, Ashwani; Siddique, Kadambot H.M.; Prasad, PV Vara; Parida, Swarup K.; Nayyar, HarshGrowing chickpea (Cicer arietinum L.) faces significant challenges due to rising temperatures and drought stress, particularly during the reproductive and seed-filling phases. This study investigated the single and joint impacts of drought and heat stress on seed development, focusing on the responses of drought-tolerant (DT) and droughtsensitive (DS) chickpea genotypes. Initially raised in an outdoor environment (mean day and night temperature of 27 and 16±1 ◦C, respectively, light intensity of 1230–1440 µmol m− 2 s − 1 , relative humidity of 70/43 %) until seed filling (around 110–113 days after sowing) commenced. The plants were subsequently exposed to single or combined heat and drought stress under controlled conditions until maturity. Control pots were maintained at day and night temperature of 25 and 15 ◦C, respectively with 500 µmol m− 2 s − 1 light, 60–65 % RH, and regular irrigation, and drought-stressed pots were kept at 50 % field capacity under the same conditions of light and humidity. Heat stress in pots was gradually increased to 32(day)/20 ◦C (night) under regular irrigation, while combined stress pots experienced both drought (50 % field capacity) and heat stress conditions 32(day)/20 ◦C (night) under the same light and humidity conditions with irrigation. All stress treatments adversely affected cell membranes, photosynthesis, and water regulation, with more pronounced effects under combined stress. While heat stress increased stomatal conductance, drought and combined stress significantly reduced it. Seed filling rate and duration decreased under all stress conditions, especially combined stress. The stresses in combination severely reduced seed weight and pod numbers compared to individual stresses. Enzyme activities involved in starch and sucrose synthesis and hydrolysis substantially decreased under the combined stress. Seed composition elements (starch, storage proteins, sugars, fat, crude fiber, and ash) exhibited significant reductions across all stress treatments, particularly for the combined stress. Thus, under combined stresses, starch, proteins, and soulube sugars were markedly decreased to 13–20 %, 6.4–12.4 %, and 3–5 % in seeds, compared to 37–39 %, 21–24 %, and 6 % in control seeds. The DT genotype outperformed the DS genotype for all traits under individual and combined stress conditions. Principal component analysis revealed a complex interplay among various physiological responses (membrane damage, chlorophyll, chlorophyll fluorescence, relative leaf water content, and stomatal conductance), seed yield, and seed composition under the combined stress. This study highlighted that combined heat and drought stress severely impacted chickpea yield and nutritional traits, such as seed starch and protein content, compared to individual stresses underscoring the need to develop cultivars tolerant to this stress combination.Item High temperature stress responses and wheat: Impacts and alleviation strategies(Elsevier B.V., 2021) Mishra, Divya; Shekhar, Shubhendu; Chakraborty, Subhra; Chakraborty, NiranjanOver the past century, the average surface temperature and recurrent heatwaves have been steadily rising, affecting the yield potential of most food crops including bread wheat, the second most important caloric source, but is particularly vulnerable to the impacts of elevated temperatures. Significantly, the past decade has witnessed tremendous advancements in multiomics approaches to extract the key regulators that influence the adaptive responses to high temperature stress (HTS). With the help of genetic engineering technologies, transgenic wheat plants have been developed showing resistance to HTS without hampering productivity. In this review, we described the effect of rising temperature at a global scale and the drastic impacts on crops, particularly on wheat production. Also, this review is focused on accomplishing a deeper understanding of the genetic and molecular basis of HTS responses of crop plants, wheat in particular along with current strategies and technologies to generate thermotolerant varieties. Collective strategy and identified thresholds of HTS tolerance and susceptibility will contribute to the value-added modelling of wheat growth and yield under predictable future climate conditions.Item Regulation of small RNA-mediated high temperature stress responses in crop plants(Springer Nature Publishing AG, 2022) Singh, Roshan Kumar; Prasad, Ashish; Maurya, Jyoti; Prasad, ManojThroughout their life cycle, plants have to regulate their gene expression at various developmental phases, physiological changes, and in response to biotic or environmental stress. High temperature is one the most common abiotic stress for crop plants, that results in impaired morphology, physiology, and yield. However, plants have certain mechanisms that enable them to withstand such conditions by modulating the expression of stress-related genes. Small RNA (sRNA)-regulated gene expression is one such mechanism which is ubiquitous in all eukaryotes. The sRNAs mainly include micro RNAs (miRNAs) and small interfering RNAs (siRNAs). They are primarily associated with the gene silencing either through translation inhibition, mRNA degradation, or DNA methylation. During high temperature stress the increased or decreased level of miRNAs altered the protein accumulation of target transcripts and, therefore, regulate stress responses. Several reports are available in plants which are genetically engineered through expressing artificial miRNAs resulted in thermotolerance. sRNAs have also been reported to bring the epigenetic changes on chromatin region through RNA-dependent DNA methylation (RdDM). The present article draws a brief illustration of sRNA origin, their functional mechanisms, role in high temperature stress, and possible application for developing stress tolerant crop plants.Item Wheat 2-Cys peroxiredoxin plays a dual role in chlorophyll biosynthesis and adaptation to high temperature(John Wiley & Sons, 2021) Mishra, Divya; Shekhar, Shubhendu; Chakraborty, Subhra; Chakraborty, NiranjanThe molecular mechanism of high temperature stress (HTS) response, in plants, has so far been investigated using transcriptomics, while the dynamics of HTS‐responsive proteome remain unexplored. We examined the adaptive responses of the resilient wheat cultivar ‘Unnat Halna’ and dissected the HTS‐responsive proteome landscape. This led to the identification of 55 HTS‐responsive proteins (HRPs), which are predominantly involved in metabolism and defense pathways. Interestingly, HRPs included a 2‐cysteine peroxiredoxin (2CP), designated Ta2CP, presumably involved in stress perception and adaptation. Complementation of Ta2CP in yeast and heterologous expression in Arabidopsis demonstrated its role in thermotolerance. Both Ta2CP silencing and overexpression inferred the involvement of Ta2CP in plant growth and chlorophyll biosynthesis. We demonstrated that Ta2CP interacts with protochlorophyllide reductase b, TaPORB. Reduced TaPORB expression was found in Ta2cp‐silenced plants, while upregulation was observed in Ta2CP‐overexpressed plants. Furthermore, the downregulation of Ta2CP in Taporb‐silenced plants and reduction of protochlorophyllide in Ta2cp‐silenced plants suggested the key role of Ta2CP in chlorophyll metabolism. Additionally, the transcript levels of AGPase1 and starch were increased in Ta2cp‐silenced plants. More significantly, HTS‐treated Ta2cp‐silenced plants showed adaptive responses despite increased reactive oxygen species and peroxide concentrations, which might help in rapid induction of high‐temperature acclimation.Item Physiological plasticity to high temperature stress in chickpea: Adaptive responses and variable tolerance(Elsevier B.V., 2019) Pareek, Akanksha; Rathi, Divya; Mishra, Divya; Chakraborty, Subhra; Chakraborty, NiranjanHigh temperature stress (HTS) is one of the most crucial factors that limits plant growth and development, and reduces crop yields worldwide. Cool-season crops, particularly the legumes, are severely affected by increasing ambient temperature associated with global climate change. We characterized the HTS-induced modulations of morpho-physicochemical traits and gene expression of several chickpea genotypes and the metabolic profile of the tolerant cultivar. Higher water use efficiency and photosynthetic capacity, minimal membrane lipid peroxidation in conjunction with increased abundance of osmolytes and secondary metabolites depicted thermotolerance of ICC 1205. The adaptive responses were accompanied by high transcript abundance of heat shock proteins and antioxidant enzymes. To integrate stress-responsive signalling and metabolic networks, the HTS-induced physicochemical analysis was further extended to metabolite profiling of the thermotolerant cultivar. The screening of the metabolome landscape led to the identification of 49 HTS-responsive metabolites that include polycarboxylic acid, sugar acids, sugar alcohols and amino acids which might confer thermotolerance in chickpea. The present study, to our knowledge, is the most comprehensive of its kind in dissecting cultivar-specific differential adaptive responses to HTS in chickpea, which might potentiate the identification of genetic traits extendible to improvement of thermotolerance of crops.
