Browsing by Author "Nitu Kumari"

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Effect of stage-specific and multi-stage drought on grain nutrient quality in rice
(Springer Science and Business Media B.V., 2023) Sahana Basu; Shashi Shekhar; Alok Kumar; Surbhi Kumari; Nitu Kumari; Sonal Kumari; Santosh Kumar; Ram Prasad; Gautam Kumar
Drought is a multidimensional stress that affects the grain nutritional quality of high yielding rice genotypes. The present study evaluated the impacts of stage-specific (seedling, vegetative, and reproductive stages) and cumulative (multi-stage) drought on ionome, starch, and protein contents in grains of two rice genotypes of eastern Indo-Gangetic plain, viz. Sahbhagi Dhan and IR64 with contrasting drought tolerance. The study showed drought to negatively affect the physiological and nutritional traits of rice grains. Following the study, stage-specific and multi-stage drought caused significant reduction in grain size, test weight, starch, amylose, amylopectin, and total soluble protein contents of rice grains. Drought during different developmental stages of rice caused significant variations in micro- (Cu, Fe, Mn, Na, Zn) and macro-nutrient (P, K, Ca, Mg) contents in the grains. Stage-specific and cumulative drought exposure of the rice genotypes also governed the ionomes in grains resulting in specific ionomic networks. Hierarchical cluster analysis showed two discrete clusters for elements as well as different drought treatments in the studied rice genotypes, which supported the results obtained from the principal component analysis, displaying five clusters based on stage-specific and multi-stage drought treatments. Variation in drought treatments and elements in different rice genotypes also altered the ionomic interactions represented by differential ionomic networks. In this study, Sahbhagi Dhan maintained the morphological and nutritional qualities of grains across the drought treatments and therefore, can be used as a suitable donor in breeding for stage-specific and cumulative drought tolerance with superior grain quality for eastern Indo-Gangetic plain. © 2023, The Author(s), under exclusive licence to Springer Nature B.V.
Reactive oxygen species and reactive nitrogen species induce lysigenous aerenchyma formation through programmed cell death in rice roots under submergence
(Elsevier B.V., 2020) Sahana Basu; Gautam Kumar; Nitu Kumari; Surbhi Kumari; Shashi Shekhar; Santosh Kumar; Ravi Rajwanshi
Nitric oxide (NO) plays a significant role in plants under different abiotic stress. However, the influence of NO and other reactive nitrogen species (RNS) in employing nitrosative stress in rice seedlings under submergence remains unexplored. Submergence also stimulates the development of lysigenous aerenchyma, facilitating oxygen supply to roots but the contribution of NO and RNS in aerenchyma formation under submergence is not known. Present study investigated the major components of the nitro-oxidative stress and their association with lysigenous aerenchyma development in the Sub1 near isogenic line of rice under submergence. Following submergence, Swarna showed increased NADPH oxidase (NOX) activity with excess reactive oxygen species (ROS) production in roots. Submergence also caused increased NO content and membrane lipid peroxidation in Swarna roots. Submergence-induced ROS and RNS accumulation in roots disturbed the redox homeostasis leading to the formation of lysigenous aerenchyma through programmed cell death (PCD). PCD was also accompanied by altered cytoplasmic streaming and DNA damage. In the present study Swarna Sub1 exhibited increased SOD, CAT, POX, APX, GR and GSNOR activity with subsequent detoxification of ROS and RNS; eventually decreasing the aerenchyma formation in root under submerged conditions. Overall, the study established ROS and RNS-mediated unique mechanism in lysigenous aerenchyma formation in rice roots under submergence. © 2020 Elsevier B.V.