Publications of NIPGR Scientists
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Item Differential regulation of nitric oxide mediated by phytoglobin1 plays a role in resistance during Botrytis cinerea infection in Arabidopsis thaliana(Springer Nature Publishing AG, 2026) Jaiswal, Rekha; Saini, Deepak; Swain, Jagannath; Gupta, Kapuganti JagadisBotrytis cinerea is a prominent necrotrophic pathogen responsible for gray mold disease, affecting a wide range of plant species, including economically vital crops such as tomatoes, grapes, strawberries, etc. Nitric oxide (NO) is considered as a crucial player in plant responses to biotic stress. NO homeostasis is regulated by phytoglobin (Pgb1), a potential scavenger of NO. However, the role of the Pgb1-NO cycle in regulating defense response against B. cinerea remains largely unknown. In the current study, we investigated the defense response of Arabidopsis thaliana against B. cinerea infection using antisense (Pgb1 AS) and overexpression (Pgb1 OE) lines, which produce differential levels of NO. The Pgb1 AS line accumulated higher NO levels and conferred resistance against B. cinerea infection, with reduced ROS levels, reduced cell death, and increased stomatal closure. Conversely, Pgb1 OE showed reduced NO levels accompanied by increased susceptibility. The elevated NO level in Pgb1 AS was associated with increased nitrate reductase (NR) activity and upregulation of NIA1 and NIA2 gene expression. Interestingly, ethylene-mediated defense pathway genes such as ERF1, ACS2, and ACS6 were upregulated while pathogen-related genes such as PR1, PR2, PR5, and NPR1 were downregulated in Pgb1 AS line. The elevated expression of ethylene genes corresponded with the higher ethylene levels in Pgb1 AS. Overall, our results confirmed the crucial role of phytoglobin-modulated NO in defense against B. cinerea infection by activating the ethylene-mediated defense pathway.Item Nitric oxide-mediated modulation of photorespiratory enzymes and photochemical components in leaves of pea plants (Pisum sativum)(John Wiley & Sons, 2026) Saini, Deepak; Bharath, Pulimamidi; Gahir, Shashibhushan; Pandey, Jayendra; Vemula, Chandra Kaladhar; Gupta, Kapuganti Jagadis; Subramanyam, Rajagopal; Raghavendra, Agepati SThe photorespiratory metabolism safeguards photosynthesis against abiotic and biotic stress. Nitric oxide (NO) and reactive oxygen species (ROS) levels rise in plants during abiotic stress. Low concentrations of NO or ROS are beneficial as signalling molecules, but they can be toxic to plant cells at high concentrations. ROS are known to modulate photorespiration; however, it is unclear whether NO affects photorespiratory enzymes and photochemical components simultaneously. We therefore used sodium nitroprusside (SNP) under dark, moderate light (ML), or high light (HL) conditions to simultaneously investigate its impact on photorespiratory enzymes and photochemical components. The NO levels were increased upon SNP exposure in Pisum sativum leaves, particularly under HL conditions. The NO release in leaves was confirmed when the NO scavenger cPTIO (2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt) was present, since it decreased the majority of elevated NO. The nitrosative/oxidative stress in Pisum sativum leaves was confirmed by the increase in nitrosothiols and tyrosine-nitrated proteins, as well as reduced aconitase activity after SNP exposure at HL. The protein levels, mRNA levels, and the enzyme activities of the following four photorespiratory enzymes: glycolate oxidase (GO), hydroxypyruvate reductase (HPR), glycerate kinase (GK), and phosphoglycolate phosphatase (PGLP) were markedly increased under elevated NO conditions. Catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) also showed increased activity, elevated protein and transcript levels upon exposure to SNP. Parallel studies on chlorophyll a fluorescence confirmed that NO restricted electron transport at both PSII and PSI, inhibited photosynthesis and respiration, and damaged photosynthetic pigments. We concluded from this study that NO at high concentrations upregulated photorespiratory enzymes while inhibiting photochemical components such as photosystem II and I (PSII/PSI) simultaneously.Item The interactions of nitric oxide with intracellular redox status and the influence of molecular hydrogen(Elsevier B.V., 2026) Hancock, J T; Corpas, F J; Kolbert, Zs; Silveira, N M; Gupta, Kapuganti JagadisNitric oxide (NO) has a wide range of effects in both animals and plants. It accumulates in cells, especially during stress responses, leading to signalling events. Many of these downstream signals rely on S-nitrosation of proteins, or nitration of proteins, but NO also interacts with a range of other cellular components, including lipids, but also other small reactive compounds. A well-known example of such a NO reaction is with the reactive oxygen species (ROS) superoxide, producing peroxynitrite. One characteristic of cells which is crucial to the control of cellular activity is the intracellular redox state, and this is maintained by compounds such as glutathione (GSH), but also impinged upon by ROS, reactive sulphur compounds such as hydrogen sulfide (H2S), and potentially by hydrogen gas (H2). Into this mix is NO, and here the potential influence of NO on cellular redox is discussed.Item Chickpea chitinases responsive to Helicoverpa herbivory and phytohormone signaling: genome-wide identification, field expression profiling, and structure-guided prioritization(BioMed Central Ltd, 2026) Konda, Aravind Kumar; Annapragada, Harika; G K, Sujayanand; Singh, Pooja; Bhuvanachandra, Bhoopal; Chinnasamy, Hariharan V; Dixit, Girish Prasad; Gupta, Kapuganti Jagadis; Matheshwaran, SaravananBackground: Chitinases can contribute to plant defence against fungal pathogens and insect herbivores, but their family organization, inducible deployment, and putative ligand-recognition behaviour remain poorly resolved in chickpea. We combined genome-wide identification, field expression profiling under controlled Helicoverpa armigera infestation, hormone treatments, and structure-guided comparison of representative proteins to prioritize defence-associated chickpea chitinases. Results: We identified 28 chickpea chitinase loci (Car_Chits), comprising 22 glycosyl hydrolase family 18 (GH18) genes and 6 GH19 genes. Local duplication, especially tandem duplication within GH18, was the main contributor to family expansion, and interpretable duplicate pairs were retained mainly under purifying selection. Promoter scans indicated broad enrichment of defence- and hormone-associated cis-elements. Field quantitative real-time PCR (qRT-PCR) profiling of 11 candidate genes in field-grown plants subjected to controlled H. armigera infestation and hormone treatments showed treatment-specific temporal regulation. Car_Chit-4 (GH19) was strongly induced by salicylic acid (7.81-fold at 0.5 h; q < 0.05) but transiently repressed shortly after H. armigera feeding (0.15-fold at 0.5 h; q = 0.030). Car_Chit-19 (GH18) was the clearest herbivory-responsive gene, with late induction at 8 h (1.62-fold; q = 0.050) and 48 h (1.85-fold; q = 0.050). Jasmonic acid caused broad early repression across several genes, followed by delayed induction of Car_Chit-4 at 24 h. Seven Car_Chit-(GlcNAc)₄ complexes were modelled, docked, and simulated for 100 ns. GH18 proteins generally showed more favourable predicted MM-PBSA binding energies than GH19 proteins, but the structural metrics were interpreted as relative ligand-recognition indicators rather than direct evidence of anti-herbivore function. Car_Chit-17 had the most favourable predicted binding energy (ΔG_bind = - 18.51 ± 6.75 kcal/mol), whereas Car_Chit-14 and Car_Chit-27 retained the most stable ligand poses and Car_Chit-19 displayed the most stable protein scaffold. Conclusions: Chickpea chitinases show differentiated temporal responses to herbivory and hormone signalling. The study supports a working model in which GH19 Car_Chit-4 marks a rapid salicylic-acid-responsive arm, whereas GH18 Car_Chit-19 marks a delayed herbivory-responsive arm. A tiered prioritization framework separates expression-deployed candidates from structure-guided biochemical candidates, explaining why different genes emerge from qRT-PCR and molecular modelling analyses. The structural analyses provide complementary prioritization of Car_Chit-17, Car_Chit-14, and Car_Chit-27 for biochemical characterization. Together, these results provide a resource for dissecting chitinase-mediated defence in chickpea and for selecting candidates for functional validation.Item Cross-species expression of OsDJ-1C from rice enhances tolerance to salinity and drought stress in tomato(Elsevier B.V., 2026) Mishra, Manjari; Chatterjee, Yajnaseni; Gupta, Brijesh Kumar; Tomar, Surabhi; Babuta, Priyanka; Gupta, Kapuganti Jagadis; Pareek, Ashwani; Singla-Pareek, Sneh LataAbiotic stresses such as salinity and drought induce the accumulation of methylglyoxal (MG), a highly cytotoxic dicarbonyl compound that disrupts cellular metabolism in plants. MG detoxification is primarily mediated by the glutathione-dependent glyoxalase pathway, classically comprising the enzymes glyoxalase I and II. In contrast, glyoxalase III (GLYIII) catalyzes detoxification of MG in a single-step without requiring glutathione. In the present study, we investigated the functional role of OsDJ-1C, a rice GLYIII enzyme, by heterologous overexpression in tomato (Solanum lycopersicum). Transgenic lines exhibited significantly enhanced stress tolerance through a more efficient antioxidant defense mechanism under stress conditions. This improvement was driven by increased GLYIII-mediated detoxification of MG, leading to effective suppression of reactive oxygen species (ROS) accumulation. Reduced ROS levels in the overexpression lines resulted in greater internal oxygen availability and enhanced cellular respiration than wild-type plants. Furthermore, transgenic plants maintained higher pyruvate levels than the wild-type controls, thereby sustaining tricarboxylic acid (TCA) cycle flux and ATP production under stress. Overall, these findings reveal a conserved, cross-species function of OsDJ-1C in enhancing abiotic stress tolerance emphasizing its relevance for improving agricultural sustainability and food security under changing climatic conditions.Item Modulation of nitric oxide mediated by Phytoglobin1 plays a role in salinity tolerance via reduced nitro-oxidative stress in Arabidopsis(Elsevier B.V., 2026) Swain, Jagannath; Babuta, Priyanka; Pandey, Sonika; Samant, Sanjib Bal; Yadav, Reena; Manbir; Hebelstrup, Kim H.; Igamberdiev, Abir U.; Singla-Pareek, Sneh Lata; Pareek, Ashwani; Gupta, Kapuganti JagadisSalinity is one of the major abiotic stresses that induces nitro-oxidative stress, which severely diminishes plant growth, development, and survival by altering various metabolic pathways. Phytoglobin (Pgb) is a nitric oxide (NO) scavenger that plays an important role in various stresses. However, the role of differential levels of phytoglobin1 in regulation of salinity stress induced nitro-oxidative stress in plants is not known. Here we characterized the role of Pgb-mediated NO in salinity tolerance by regulation of nitro-oxidative stress using Pgb1 overexpressing (Pgb1-OE) and silencing lines (pgb1-AS) of Arabidopsis. We found that imposing salinity leads to enhanced expression of Pgb1. NO measurement by both chemiluminescence and DAF-FM-DA suggested that salinity stress induces NO production. Pgb1-OE lines showed reduced levels of NO which is accompanied by reduced ROS, superoxide and H2O2 levels. On the contrary, pgb1-AS lines showed increased NO and ROS under salt stress. Further, gene expression analysis revealed an elevated expression of antioxidant genes in Pgb1-OE line in comparison to WT and pgb1-AS lines under salinity stress. Pgb1-OE lines showed enhanced survival which is correlated with reduced peroxynitrite and tyrosine nitration and opposing effect was observed in pgb1-AS lines along with increased cell death. Taken together, our study revealed that modulation of Pgb1 enhances tolerance to salinity-induced nitro-oxidative stress.Item OsLdh3 interacts with OsGAPC3 and OsLos2 to maintain the glycolytic continuum for tolerance to multiple abiotic stresses in rice(Oxford University Press, 2026) Chatterjee, Yajnaseni; Babuta, Priyanka; Gupta, Kapuganti Jagadis; Pareek, Ashwani; Singla-Pareek, Sneh LataLactate dehydrogenases are oxidoreductases present in almost all living organisms. They catalyze the interconversion of pyruvate and L-lactate with simultaneous oxidation of NADH and reduction of NAD+. Since their function remains largely unexplored in rice, in this study we deciphered the role of the rice lactate dehydrogenase, OsLdh3. OsLdh3 showed optimum enzyme activity at pH 6.6 for the forward reaction (pyruvate to L-lactate) and pH 9 for the reverse reaction (L-lactate to pyruvate). Protein-protein interaction studies revealed that OsLdh3 interacts with the glycolytic enzymes glyceraldehyde 3-phosphate dehydrogenaseC3 (OsGAPC3) and Enolase2 (OsLos2), suggesting its role in regulating glycolytic flux. Further, overexpression of OsLdh3 in rice showed enhanced abiotic stress tolerance by exhibiting elevated NAD+ levels and OsGAPC3 activity, thereby facilitating an improved glycolytic continuum and higher pyruvate accumulation. Consequently, these lines also showed increased mitochondrial respiration and ATP synthesis, and reduced reactive oxygen species (ROS) accumulation. Further, enhanced photosynthetic efficiency and reduced yield penalty of the stress-imposed OsLdh3 overexpression lines underscore its importance in crop productivity under adverse climatic conditions. Thus, our findings show that OsLdh3 enhances stress tolerance in rice by regulating redox homeostasis and respiration, reducing ROS levels, and maintaining energy balance. This makes OsLdh3 a promising candidate gene for developing climate-resilient rice cultivars with reduced yield gap.Item Expression analysis of ROS-related genes during the germination of chickpea (Cicer Arietinum L.) seeds(Springer Nature Publishing AG, 2026) Babuta, Priyanka; Samant, Sanjib Bal; Saini, Deepak; Gupta, Kapuganti JagadisSeed germination is a critical physiological process that transforms a quiescent seed into a metabolically active seedling and is also a crucial factor in determining maximum crop production. This transition is influenced by various intrinsic and extrinsic factors. Interestingly, reactive oxygen species (ROS) plays an important role in breaking seed dormancy by oxidation of biomolecules, weakening of the testa and degradation of endosperm. Similarly, molecular internal oxygen is also considered vital for the transition of dormancy to seed germination. However, it is essential to establish a correlation between the internal oxygen and the generation of ROS during seed germination. This chapter details protocols for imaging internal oxygen concentrations using VisiSens and fluorescent detection of ROS using H2DCFDA in chickpea seeds, complemented by qPCR analysis of key ROS-related genes (RBOH, AOX 1, UCP 1, and NADH dehydrogenase). These findings from these methods help advance our understanding of the inverse relationship between molecular oxygen and ROS dynamics during seed germination.Item Method for the measurement of ethylene during hypoxia in rice plants(Springer Nature Publishing AG, 2025) Jaiswal, Rekha; Gupta, Kapuganti Jagadis; Praveen, AfsanaEthylene is a versatile phytohormone that is involved in the regulation of both growth and development such as senescence, and also it can act as a signaling hormone during hypoxia. Ethylene acts alone or in interaction with different phytohormones and proteins to regulate numerous cellular processes. Accumulating evidence suggest that endogenous ethylene production and emission into atmosphere are modulated by various biotic and abiotic stresses. Since it is a gaseous hormone, a precise detection, particularly under low-oxygen (hypoxic) conditions, is important for understanding its role in regulatory processes and stress signaling pathways. Currently, measurement practices such as gas chromatography, electrochemical sensing, and optical sensing are widely employed to detect ethylene. These methods are distinct from each other in terms of sensitivity, time response, selectivity, and cost. However, each method has its own advantages and limitations. Gas chromatography (GC) is one of the best techniques that is applied for the separation and measurement of ethylene due to its volatile and supersensitive nature. In this chapter, we describe a detailed GC-based procedure specifically optimized for measuring ethylene levels during hypoxic stress application in (Oryza sativa) rice plants.Item Method for the measurement of ethylene during pathogen infection in arabidopsis(Springer Nature Publishing AG, 2025) Jaiswal, Rekha; Gupta, Kapuganti Jagadis; Praveen, AfsanaEthylene is a gaseous phytohormone that plays an important role as a signaling molecule during pathogen attack, influencing disease resistance and defense responses in plants. A precise measurement of ethylene production upon pathogen challenge is essential to elucidate its role in plant–pathogen interactions. Gas chromatography (GC) is among the most accurate and sensitive techniques for detecting and quantifying ethylene emissions due to its selectivity and effectiveness with gaseous molecules. In this chapter, we provide a detailed procedure employing GC specifically adapted for measuring ethylene levels during pathogen infection (Botrytis cinerea) in Arabidopsis leaflets. Arabidopsis leaflets infected by the necrotrophic pathogen Botrytis cinerea exhibit increased ethylene emission, facilitating the activation of defense pathways and secondary metabolites such as camalexin. The present GC method captures ethylene dynamics at early infection stages, ensuring precise quantification critical for dissecting the molecular mechanisms of plant immunity.