Institutional Publications

Permanent URI for this collectionhttps://ndkr-library.nipgr.ac.in/handle/123456789/11

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Author: search.filters.author.Fernie, Alisdair R.Start date: 2020

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    The multifaceted metabolic role of lactate dehydrogenase in submergence tolerance
    (John Wiley & Sons, 2026) Swain, Jagannath; Fernie, Alisdair R.; Foyer, Christine H.; Gupta, Kapuganti Jagadis
    In this commentary, we highlight the importance of LDH in the modulation of several crucial metabolic pathways for submergence tolerance in rice. Lactate Dehydrogenase (LDH), a tetrameric enzyme that catalyses the reversible interconversion of pyruvate and lactate during fermentation induced by hypoxia in plants and animals. Catalysing an important rate-limiting step in the glyco-metabolism pathway, the increased expression and activity of this enzyme are required for the maintenance of glycolysis under hypoxia, protecting energy homeostasis by maintaining NADH/NAD+ ratios (Ha et al. 2024). Recent evidence demonstrated the importance of LDH in the modulation of several metabolic pathways for submergence tolerance in rice (Chatterjee et al. 2025).
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    Serine hydroxymethyltransferase6 is involved in growth and resistance against pathogens via ethylene and lignin production in Arabidopsis
    (John Wiley & Sons, 2024) Singh, Pooja; Kumari, Aprajita; Khaladhar, Vemula Chandra; Singh, Namrata; Pathak, Pradeep Kumar; Kumar, Vinod; Kumar, Ritika Jantu; Jain, Priyanka; Thakur, Jitendra K.; Fernie, Alisdair R.; Bauwe, Hermann; Raghavendra, A.S.; Gupta, Kapuganti Jagadis
    Photorespiratory serine hydroxymethyltransferases (SHMTs) are important enzymes of cellular one-carbon metabolism. In this study, we investigated the potential role of SHMT6 in Arabidopsis thaliana. We found that SHMT6 is localized in the nucleus and expressed in different tissues during development. Interestingly SHMT6 is inducible in response to avirulent, virulent Pseudomonas syringae and to Fusarium oxysporum infection. Overexpression of SHMT6 leads to larger flowers, siliques, seeds, roots, and consequently an enhanced overall biomass. This enhanced growth was accompanied by increased stomatal conductance and photosynthetic capacity as well as ATP, protein, and chlorophyll levels. By contrast, a shmt6 knockout mutant displayed reduced growth. When challenged with Pseudomonas syringae pv tomato (Pst) DC3000 expressing AvrRpm1, SHMT6 overexpression lines displayed a clear hypersensitive response which was characterized by enhanced electrolyte leakage and reduced bacterial growth. In response to virulent Pst DC3000, the shmt6 mutant developed severe disease symptoms and becomes very susceptible, whereas SHMT6 overexpression lines showed enhanced resistance with increased expression of defense pathway associated genes. In response to Fusarium oxysporum, overexpression lines showed a reduction in symptoms. Moreover, SHMT6 overexpression lead to enhanced production of ethylene and lignin, which are important components of the defense response. Collectively, our data revealed that SHMT6 plays an important role in development and defense against pathogens.
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    The uncoupling of respiration in plant mitochondria: keeping reactive oxygen and nitrogen species under control
    (Oxford University Press, 2021) Popov, Vasily N.; Syromyatnikov, Mikhail Y.; Fernie, Alisdair R.; Chakraborty, Subhra; Gupta, Kapuganti Jagadis; Igamberdiev, Abir U.
    Plant mitochondrial respiration involves the operation of various alternative pathways. These pathways participate, both directly and indirectly, in the maintenance of mitochondrial functions though they do not contribute to energy production, being uncoupled from the generation of an electrochemical gradient across the mitochondrial membrane and thus from ATP production. Recent findings suggest that uncoupled respiration is involved in reactive oxygen species (ROS) and nitric oxide (NO) scavenging, regulation, and homeostasis. Here we discuss specific roles and possible functions of uncoupled mitochondrial respiration in ROS and NO metabolism. The mechanisms of expression and regulation of the NDA-, NDB- and NDC-type non-coupled NADH and NADPH dehydrogenases, the alternative oxidase (AOX), and the uncoupling protein (UCP) are examined in relation to their involvement in the establishment of the stable far-from-equilibrium state of plant metabolism. The role of uncoupled respiration in controlling the levels of ROS and NO as well as inducing signaling events is considered. Secondary functions of uncoupled respiration include its role in protection from stress factors and roles in biosynthesis and catabolism. It is concluded that uncoupled mitochondrial respiration plays an important role in providing rapid adaptation of plants to changing environmental factors via regulation of ROS and NO.
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    The role of nitrite and nitric oxide under low oxygen conditions in plants
    (Oxford University Press, 2020) Gupta, Kapuganti Jagadis; Mur, Luis A.J.; Wany, Aakanksha; Kumari, Aprajita; Fernie, Alisdair R.; Ratcliffe, R. George
    Plant tissues, particularly roots, can be subjected to periods of hypoxia due to environmental circumstances. Plants have developed various adaptations in response to hypoxic stress and these have been extensively described. Less well-appreciated is the body of evidence demonstrating that scavenging of nitric oxide (NO) and the reduction of nitrate/nitrite regulate important mechanisms that contribute to tolerance to hypoxia. Whilst ethylene controls hyponasty and aerenchyma formation, NO production apparently regulates hypoxic ethylene biosynthesis. In the hypoxic mitochondrion, cytochrome c oxidase, which is a major source of NO, is also inhibited by NO, thereby reducing the respiratory rate and enhancing local oxygen concentrations. Nitrite can maintain ATP generation under hypoxia by coupling its reduction to the translocation of protons from the inner side of mitochondria and generating an electrochemical gradient. This reaction can be further coupled to a reaction whereby non-symbiotic haemoglobin oxidizes NO to nitrate. In addition to these functions, nitrite has been reported to influence mitochondrial structure and supercomplex formation, as well as playing a role in oxygen sensing via the N-end rule pathway. These studies establish that nitrite and NO perform multiple functions during plant hypoxia and suggest that further research into the underlying mechanisms is warranted.