Browsing by Author "Prasad, P. V. Vara"

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Assessing cold stress resilience in wild chickpea accessions using physiological, biochemical, and reproductive traits
(Springer Nature, 2025) Kaur, Sarbjeet; Padhiar, Deeksha; Singh, Mohar; Parida, Swarup K.; Jha, Uday C.; Sharma, Kamal Dev; Prasad, P. V. Vara; Siddique, Kadambot H. M.; Nayyar, Harsh
Domesticated chickpea (Cicer arietinum L.) exhibits high sensitivity to temperatures below 20/10 °C during its reproductive phase resulting in substantial loss of flowers, pods and crop yields. With the aim to add new sources of cold tolerance and elucidate mechanism of cold-tolerance in wild species of chickpea, the present study evaluated 36 wild accessions of three Cicer species (Cicer judaicum, Cicer pinnatifidum, Cicer reticulatum) at the reproductive stage for yield, and reproductive, physiological and biochemical traits under cold stress (15/7 °C) for two consecutive years. Cluster analysis based on yield-related traits such as pod number, seed weight, and total seed count categorized these accessions as cold-tolerant and cold-sensitive. Six C. judaicum accessions (ILWC 256, ICC 13852, ILWC 263, ILWC 20, ILWC 223, and ILWC 30) were tolerant to cold whereas the remaining ones were cold-sensitive. Under cold stress, cold-tolerant accessions exhibited lower impairment of physiological processes as compared to the cold-sensitive accessions e.g. lower tissue damage and electrolyte leakage, and higher chlorophyll content, carotenoid content, chlorophyll fluorescence, and leaf water content, thereby resulting in higher photosynthetic efficiency and carbohydrate accumulation in cold-tolerant accessions. At the biochemical level, the tolerant accessions demonstrated significantly higher amounts of cryoprotectants and enhanced activities of enzymatic and non-enzymatic antioxidants resulting in substantially lower levels of reactive oxygen species. Cold-tolerant accessions also accumulated more proline and trehalose compared to their sensitive counterparts. Slight disruptions in physiological processes, low oxidative stress and accumulation of cryoprotectants under cold stress were associated with higher pollen viability, pollen germination, pollen load, ovule receptivity, pod set, number of pods and seed yield in cold-tolerant accessions while opposite was true for cold-sensitive accessions. The wild chickpea accessions exhibiting high seed yield under cold stress are promising candidates for breeding programs aimed at cold tolerance.
Deciphering the dynamics of enzymes associated with the synthesis of cryoprotectants during cold acclimation in contrasting chickpea genotypes
(Springer Nature Publishing AG, 2025) Padhiar, Deeksha; Kaur, Sarbjeet; Rani, Anju; Jha, Uday Chand; Prasad, P. V. Vara; Sharma, Kamal Dev; Kumar, Sanjeev; Parida, Swarup K.; Siddique, Kadambot H. M.; Nayyar, Harsh
Chickpea, a vital legume crop, is highly susceptible to cold stress, especially during its reproductive phase, resulting in significant flower and pod abortions and reduced seed yield. Our previous study demonstrated that cold acclimation is effective in enhancing cold tolerance but benefits only cold-tolerant (CT) genotypes, while cold-sensitive (CS) genotypes remain unaffected. In this extended study aimed at probing the detailed mechanisms of this differential response, we further examined the expression profiles of enzymes involved in the synthesis and breakdown of osmolytes (pyrroline-5-carboxylate synthase, proline dehydrogenase (PDH), betaine aldehyde dehydrogenase) and sugars (sucrose synthase, acid invertase, trehalose-6-phosphate synthase, trehalose-6-phosphate phosphatase, and trehalase activity), along with the expression of various antioxidants (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase) in both CT and CS genotypes. Seeds of two contrasting chickpea genotypes, cold-tolerant ICC 17258 and cold-sensitive ICC 15567, were planted in pots during the first week of November in an outdoor field environment. After 40 days, the plants were transferred to walk-in growth chambers for cold acclimation at specific temperatures. Initially, the plants were exposed the plants to 25/18℃ (pre-acclimation stage; PAS) for 2 days, followed by a 21-day cold acclimation period with progressively decreasing temperatures over seven days for each cold acclimation stage (CAS): CAS1 (21/13℃), CAS2 (18/10℃), and CAS3 (15/8℃). Subsequently, the plants were subjected to cold stress at 13/7℃ for 15 days and then exposed to 30/23℃ (12 h day/night) until maturity. Our findings demonstrated that the expression of various enzymes involved in the synthesis of osmolytes and sugars in leaves, anthers, and ovules was significantly upregulated during the cold acclimation process in the CT chickpea genotypes but not in the CS genotypes. This enhanced metabolic activity, coupled with elevated levels of enzymatic antioxidants during the acclimation process, contributed to improved leaf water status, photosynthetic efficiency, and ultimately, superior reproductive performance (pollen germination, pollen viability, stigma receptivity, and ovule viability) under cold stress conditions compared to CS genotypes. The enhanced cold tolerance observed in the CT genotypes is likely attributable to their genetic predisposition and efficient stress defense mechanisms facilitated by the upregulated expression of cold-responsive enzymes.
Differential resilience of chickpea's reproductive organs to cold stress across developmental stages: insights into antioxidant strategies for enhanced fertility
(Frontiers Media S.A., 2025) Padhiar, Deeksha; Kaur, Sarbjeet; Jha, Uday Chand; Prasad, P. V. Vara; Sharma, Kamal Dev; Kumar, Sanjeev; Parida, Swarup Kumar; Siddique, Kadambot H M; Nayyar, Harsh
Chickpea is highly sensitive to cold stress during its reproductive stages, leading to significant reductions in potential pod formation due to decreased reproductive success. This study aimed to investigate the specific responses of anthers and ovules to cold stress, explore the role of oxidative stress and antioxidant mechanisms, and understand the relationship between oxidative stress and reproductive function to enhance our understanding of chickpea responses to cold stress. Chickpea seeds of contrasting genotypes—cold-tolerant (ICC 17258, ICC 16349) and cold-sensitive (ICC 15567, GPF 2)—were sown outdoors in early November under optimal conditions (25.5/15.4°C mean day/night temperatures). At 50 days after sowing, plants were subjected to 13/7°C cold stress (12 h light/dark in walk-in growth chambers. Cold stress significantly increased membrane damage and reduced cellular viability in anthers and ovules, particularly in cold-sensitive (CS) genotypes. Oxidative damage was more pronounced in anthers, particularly at anthesis (stage 2), as indicated by elevated malondialdehyde and hydrogen peroxide levels. Cold-tolerant (CT) genotypes exhibited increased antioxidant activity under stress, especially at pre-anthesis (stage 1), followed by declines at later stage, although responses varied by genotype. Anthers exhibited higher overall antioxidants activity than ovules, while ovules demonstrated notably high catalase activity. Among the antioxidants studied, ascorbate peroxidase and glutathione reductase were most prominent in the CT genotype, along with higher levels of ascorbate (AsA) and glutathione (GSH), highlighting the critical role of the AsA–GSH cycle in conferring cold tolerance to chickpea. Exogenous supplementation with 1 mM ascorbate (AsA) and glutathione (GSH) significantly stimulated pollen germination in cold-stressed plants under in vitro conditions, with a greater effect observed in CS genotypes. Furthermore, antioxidant activity strongly correlated with key reproductive traits such as pollen germination and ovule viability. This study revealed that the anthers and ovules exhibited distinct responses to cold stress, with significant genotypic differences across key reproductive stages. These insights provide a deeper understanding of cold tolerance mechanisms in chickpea and provide vital clues for breeding strategies to enhance resilience and reproductive success under cold stress.
A next-generation combinatorial genomic strategy scans genomic loci governing heat stress tolerance in chickpea
(John Wiley & Sons, 2025) Mohanty, Jitendra K.; Yadav, Antima; Narnoliya, Laxmi; Thakro, Virevol; Nayyar, Harsh; Dixit, Girish P.; Jha, Uday Chand; Prasad, P. V. Vara; Agarwal, Pinky; Parida, Swarup K.
In the wake of rising earth temperature, chickpea crop production is haunted by the productivity crisis. Chickpea, a cool season legume manifests tolerance in several agro-physiological level, which is complex quantitative in nature, and regulated by multiple genes and genetic networks. Understanding the molecular genetic basis of this tolerance and identifying key regulators can leverage chickpea breeding against heat stress. This study employed a genomics-assisted breeding strategy utilizing multi-locus GWAS to identify 10 key genomic regions linked to traits contributing to heat stress tolerance in chickpea. These loci subsequently delineated few key candidates and hub regulatory genes, such as RAD23b, CIPK25, AAE19, CK1 and WRKY40, through integrated genomics, transcriptomics and interactive analyses. The differential transcript accumulation of these identified candidates in contrasting chickpea accessions suggests their potential role in heat stress tolerance. Differential ROS accumulation along with their scavengers' transcript abundance aligning with the expression of identified candidates in the contrasting chickpea accessions persuade their regulatory significance. Additionally, their functional significance is ascertained by heterologous expression and subsequent heat stress screening. The high confidence genomic loci and the superior genes and natural alleles delineated here has great potential for swift genomic interventions to enhance heat resilience and yield stability in chickpea.
Nitric oxide-mediated modulation of reproductive resilience under cold stress in chickpea
(Frontiers Media S.A., 2025) Kaur, Sarbjeet; Padhiar, Deeksha; Jha, Uday Chand; Kumar, Sanjeev; Sharma, Kamal Dev; Parida, Swarup Kumar; Siddique, Kadambot H. M.; Prasad, P. V. Vara; Nayyar, Harsh
Chickpeas are particularly sensitive to cold stress during the reproductive phase, which can significantly impair pod set and yield. This study examined the role of sodium nitroprusside (SNP), a nitric oxide (NO) donor, in mitigating cold-induced reproductive damage in cold-tolerant (CT) and cold-sensitive (CS) chickpea genotypes. After 100 days of outdoor growth, plants were subjected to cold stress (15/8°C day/night; 12 h photoperiod) for 21 days in walk-in growth chambers during the reproductive stage of development. Control plants were maintained at 25/15°C day/night temperature. SNP treatment (1 mM) was applied exogenously each time, first two days prior to stress onset and then at seven-day intervals (three applications total). Cold stress significantly lowered endogenous NO levels in leaves, anthers, and ovules, particularly in CS genotypes, thereby leading to reduced pollen viability and germination. SNP treatment restored NO and improved reproductive performance, with stronger responses in the CS than the CT genotype. For instance, pollen germination increased by 57.9% in CS versus 17.6% in CT, and pollen viability increased by 28.0% and 13.1%, respectively. Enhanced anther function resulted in a 157.2% increase in pod set and 62.0% higher seed yield in CS. SNP also improved physiological traits, including a 43.9% increase in cellular viability, 18.6% in stomatal conductance, and 41.9% in chlorophyll content in CS genotypes. Cryoprotectants (proline, trehalose, and sucrose) accumulated in anthers, reinforcing cold resilience, while oxidative stress was simultaneously alleviated through reduced malondialdehyde, hydrogen peroxide, and electrolyte leakage, together with the upregulation of both enzymatic (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APx), and glutathione reductase (GR)) and non-enzymatic (ascorbic acid (ASC) and reduced glutathione (GSH)) components. Notably, CS genotypes showed more pronounced improvements from SNP application than CT genotypes, particularly in terms of reproductive success and yield-related traits. These findings highlight the potential of NO donors, such as SNP, to enhance cold tolerance in chickpeas, with promising implications for safeguarding productivity under low-temperature stress, especially in sensitive cultivars.
Non-coding RNAs (ncRNAs) in plant: Master regulators for adapting to extreme temperature conditions
(Elsevier B.V., 2023) Jha, Uday Chand; Nayyar, Harsh; Roychowdhury, Rajib; Prasad, P. V. Vara; Parida, Swarup K.; Siddique, Kadambot H. M.
Unusual daily temperature fluctuations caused by climate change and climate variability adversely impact agricultural crop production. Since plants are immobile and constantly receive external environmental signals, such as extreme high (heat) and low (cold) temperatures, they have developed complex molecular regulatory mechanisms to cope with stressful situations to sustain their natural growth and development. Among these mechanisms, non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs), small-interfering RNAs (siRNAs), and long-non-coding RNAs (lncRNAs), play a significant role in enhancing heat and cold stress tolerance. This review explores the pivotal findings related to miRNAs, siRNAs, and lncRNAs, elucidating how they functionally regulate plant adaptation to extreme temperatures. In addition, this review addresses the challenges associated with uncovering these non-coding RNAs and understanding their roles in orchestrating heat and cold tolerance in plants.
Response of physiological, reproductive function and yield traits in cultivated chickpea (Cicer arietinum L.) under heat stress
(Frontiers Media S.A., 2022) Devi, Poonam; Jha, Uday Chand; Prakash, Vijay; Kumar, Sanjeev; Parida, Swarup K.; Paul, Pronob J.; Prasad, P. V. Vara; Sharma, Kamal Dev; Siddique, Kadambot H.M.; Nayyar, Harsh
Under global climate change, high-temperature stress is becoming a major threat to crop yields, adversely affecting plant growth, and ultimately resulting in significant yield losses in various crops, including chickpea. Thus, identifying crop genotypes with increased heat stress (HS) tolerance is becoming a priority for chickpea research. Here, we assessed the response of seven physiological traits and four yield and yield-related traits in 39 chickpea genotypes grown in normal-sown and late-sown environments [to expose plants to HS (>32/20°C) at the reproductive stage] for two consecutive years (2017-2018 and 2018-2019). Significant genetic variability for the tested traits occurred under normal and HS conditions in both years. Based on the tested physiological parameters and yield-related traits, GNG2171, GNG1969, GNG1488, PantG186, CSJ515, RSG888, RSG945, RVG202, and GNG469 were identified as promising genotypes under HS. Further, ten heat-tolerant and ten heat-sensitive lines from the set of 39 genotypes were validated for their heat tolerance (32/20°C from flowering to maturity) in a controlled environment of a growth chamber. Of the ten heat-tolerant genotypes, GNG1969, GNG1488, PantG186, RSG888, CSJ315, and GNG1499 exhibited high heat tolerance evidenced by small reductions in pollen viability, pollen germination, and pod set %, high seed yield plant-1 and less damage to membranes, photosynthetic ability, leaf water status, and oxidative processes. In growth chamber, chlorophyll, photosynthetic efficiency, pollen germination, and pollen viability correlated strongly with yield traits. Thus, GNG1969, GNG1488, PantG186, RSG888, CSJ315, and GNG1499 genotypes could be used as candidate donors for transferring heat tolerance traits to high-yielding heat-sensitive varieties to develop heat-resilient chickpea cultivars.