Publications of NIPGR Scientists

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    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 S
    The 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.
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    Photosynthetic adaptation in poplar under abiotic and biotic stress: integrating molecular, physiological, and biotechnological perspectives
    (MDPI AG, 2025) Wang, Dong; Jewaria, Pawan Kumar; Xiao, Jianwei
    In the context of global climate change, the carbon storage and sequestration capacity of terrestrial ecosystems is of increasing concern. Poplars are widely planted because of their fast growth and environmental adaptability. We reviewed the effects of abiotic and biotic stresses on photosynthesis in poplar, focusing on the damage caused by adversity conditions to photosynthetic apparatus, which leads to decreased carbon dioxide (CO2) assimilation and an increase in reactive oxygen species (ROS)-induced oxidative damage. The mechanisms of photosynthesis response to stress in poplar are reviewed, especially the role of genes regulation in regulating photosynthetic efficiency. These findings are particularly important for improving the resilience of poplar under changing environmental conditions. In addition, we discussed a range of strategies to enhance photosynthesis in poplar under stress, such as genetic engineering and synthetic biology. These approaches provide theoretical guidance for improving the resilience of poplar and insights for improving other crops facing similar challenges.
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    Dehydration-responsive chickpea chloroplast protein, CaPDZ1, confers dehydration tolerance by improving photosynthesis
    (John Wiley & Sons, 2022) Lande, Nilesh Vikram; Barua, Pragya; Gayen, Dipak; Wardhan, Vijay; Jeevaraj, Theboral; Kumar, Sunil; Chakraborty, Subhra; Chakraborty, Niranjan
    The screening of a dehydration-responsive chloroplast proteome of chickpea led us to identify and investigate the functional importance of an uncharacterized protein, designated CaPDZ1. In all, we identified 14 CaPDZs, and phylogenetic analysis revealed that these belong to photosynthetic eukaryotes. Sequence analyses of CaPDZs indicated that CaPDZ1 is a unique member, which harbours a TPR domain besides a PDZ domain. The global expression analysis showed that CaPDZs are intimately associated with various stresses such as dehydration and oxidative stress along with certain phytohormone responses. The CaPDZ1-overexpressing chickpea seedlings exhibited distinct phenotypic and molecular responses, particularly increased photosystem (PS) efficiency, ETR and qP that validated its participation in PSII complex assembly and/or repair. The investigation of CaPDZ1 interacting proteins through Y2H library screening and co-IP analysis revealed the interacting partners to be PSII associated CP43, CP47, D1, D2 and STN8. These findings supported the earlier hypothesis regarding the role of direct or indirect involvement of PDZ proteins in PS assembly or repair. Moreover, the GUS-promoter analysis demonstrated the preferential expression of CaPDZ1 specifically in photosynthetic tissues. We classified CaPDZ1 as a dehydration-responsive chloroplast intrinsic protein with multi-fold abundance under dehydration stress, which may participate synergistically with other chloroplast proteins in the maintenance of the photosystem.
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    Decoding the gene coexpression network underlying the ability of Gevuina avellana to live in diverse light conditions
    (John Wiley & Sons, 2018) Ostria-Gallardo, Enrique; Ranjan, Aashish; Ichihashi, Yasunori; Corcuera, Luis J.; Sinha, Neelima R.
    Gevuina avellana (Proteaceae) is a typical tree from the South American temperate rainforest. Although this species mostly regenerates in shaded understories, it exhibits an exceptional ecological breadth, being able to live under a wide range of light conditions. Here we studied the genetic basis that underlies physiological acclimation of the photosynthetic responses of G. avellana under contrasting light conditions. We analyzed carbon assimilation and light energy used for photochemical processes in plants acclimated to contrasting light conditions. Also, we used a transcriptional profile of leaf primordia from G. avellana saplings growing under different light environments in their natural habitat, to identify the gene coexpression network underpinning photosynthetic performance and light-related processes. The photosynthetic parameters revealed optimal performance regardless of light conditions. Strikingly, the mechanism involved in dissipation of excess light energy showed no significant differences between high- and low-light-acclimated plants. The gene coexpression network defined a community structure consistent with the photochemical responses, including genes involved mainly in assembly and functioning of photosystems, photoprotection, and retrograde signaling. This ecophysiological genomics approach improves our understanding of the intraspecific variability that allows G. avellana to have optimal photochemical and photoprotective mechanisms in the diverse light habitats it encounters in nature.
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    Genetic dissection of photosynthetic efficiency traits for enhancing seed yield in chickpea
    (John Wiley & Sons, 2019) Basu, Udita; Bajaj, Deepak; Sharma, Akash; Malik, Naveen; Daware, Anurag; Narnoliya, Laxmi; Thakro, Virevol; Upadhyaya, Hari D.; Kumar, Rajendra; Tripathi, Shailesh; Bharadwaj, Chellapilla; Tyagi, Akhilesh K.; Parida, Swarup K.
    Understanding the genetic basis of photosynthetic efficiency (PE) contributing to enhanced seed yield per plant (SYP) is vital for genomics-assisted crop improvement of chickpea. The current study employed an integrated genomic strategy involving photosynthesis pathway gene-based association mapping, genome-wide association study, QTL mapping and expression profiling. This identified 16 potential SNP loci linked to major QTLs underlying 16 candidate genes significantly associated with PE and SYP traits in chickpea. The allelic variants were tightly linked to positively interacting QTLs regulating both enhanced PE and SYP traits as exemplified by a chlorophyll A-B binding protein-coding gene. The leaf tissue-specific pronounced up-regulated expression of 16 associated genes in germplasm accessions and homozygous individuals of mapping population was evident. Such combinatorial genomic strategy coupled with gene haplotype-specific association as well as in silico protein-protein interaction study delineated natural alleles and superior haplotypes from a chlorophyll A-B binding protein-coding gene and its interacting gene, Timing of CAB Expression 1, which appear to be most-promising candidates in modulating chickpea PE and SYP traits. These functionally pertinent molecular signatures identified have efficacy to drive marker-assisted selection for developing PE-enriched cultivars with high seed yield in chickpea.
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    Alterations in rice chloroplast integrity, photosynthesis and metabolome associated with pathogenesis of Rhizoctonia solani
    (Nature Publishing Group, 2017) Ghosh, S; Kanwar, P; Jha, Gopaljee
    Sheath blight disease is caused by a necrotrophic fungal pathogen Rhizoctonia solani and it continues to be a challenge for sustainable rice cultivation. In this study, we adopted a multi-pronged approach to understand the intricacies of rice undergoing susceptible interactions with R. solani. Extensive anatomical alteration, chloroplast localized ROS, deformed chloroplast ultrastructure along with decreased photosynthetic efficiency were observed in infected tissue. GC-MS based metabolite profiling revealed accumulation of glycolysis and TCA cycle intermediates, suggesting enhanced respiration. Several aromatic and aliphatic amino acids along with phenylpropanoid intermediates were also accumulated, suggesting induction of secondary metabolism during pathogenesis. Furthermore, alterations in carbon metabolism along with perturbation of hormonal signalling were highlighted in this study. The gene expression analysis including RNAseq profiling reinforced observed metabolic alterations in the infected tissues. In conclusion, the present study unravels key events associated during susceptible rice-R. solani interactions and identifies metabolites and transcripts that are accumulated in infected tissues.
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    Plant physiology meets phytopathology: relations between plant primary metabolism and plant-pathogen-interactions
    (Oxford University Press, 2007) Berger, Susanne; Sinha, Alok Krishna; Roitsch, Thomas
    Phytopathogen infection leads to changes in secondary metabolism based on the induction of defence programmes as well as to changes in primary metabolism which affect growth and development of the plant. Therefore, pathogen attack causes crop yield losses even in interactions which do not end up with disease or death of the plant. While the regulation of defence responses has been intensively studied for decades, less is known about the effects of pathogen infection on primary metabolism. Recently, interest in this research area has been growing, and aspects of photosynthesis, assimilate partitioning, and source– sink regulation in different types of plant–pathogen interactions have been investigated. Similarly, phytopathological studies take into consideration the physiological status of the infected tissues to elucidate the fine-tuned infection mechanisms. The aim of this review is to give a summary of recent advances in the mutual interrelation between primary metabolism and pathogen infection, as well as to indicate current developments in non-invasive techniques and important strategies of combining modern molecular and physiological techniques with phytopathology for future investigations.