Publications of NIPGR Scientists

Permanent URI for this communityhttps://ndkr-library.nipgr.ac.in/handle/123456789/1

Browse

Start date: 2020Subject: search.filters.subject.photosynthesis

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    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 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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.