Browsing by Author "Khatoon, Narjis Saba"

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Anaerobic-aerobic swerve in arsenic-stressed deepwater rice genotype under submergence
(John Wiley & Sons, 2025) Khan, Asna; Khatoon, Narjis Saba; Vadassery, Jyothilakshmi; Gupta, Meetu
Global floods in arsenic (As)-stressed paddy fields affect rice productivity. Future predictions of flood-related disasters provoke an urge to opt for climate-smart varieties for a secure supply. Thus, this study is designed to present the mechanisms favoring a traditional variety Mini mansoori (M.M) to withstand the dual stress of As and submergence (Sub). The investigation involved the identification of the key attributes regulating the physio-biochemical shifts in 3- and 7-day (d) submerged plants. Our results indicated that at 3 days, gas-film (GF) decrement correlated with reduced photosynthesis and Kreb-cycle enzymes. This, in turn, stimulated anaerobic enzymes, salicylic acid, and gibberellic acid (SA-GA) production, which increased glutamate metabolism through GDH enzyme, ultimately enhancing GABA and proline production to cover the energy gap. Proline dehydrogenase enzyme at 3 days monitored the stabilized proline turnover by catabolizing proline into glutamate while releasing reducing equivalents for additional ATP generation. However, at 7 days, further enhancement in GA content led to shoot elongation. The expanded GF and new leaf emergence recovered the photosynthetic machinery, TCA functioning, sugar reserves, and GABA content via proline homeostasis. This proline metabolic balance accentuated As tolerance and Sub resistance, henceforth presenting M.M. var. as climate smart for future crop improvements.
Nutrient use efficiency promoted hormonal crosstalk and stomatal dynamics in wheat under the co-impact of arsenic and drought
(Elsevier B.V., 2025) Khatoon, Narjis Saba; Khan, Asna; Bhatia, Priyanka; Vadassery, Jyothilakshmi; Gupta, Meetu
This study presents the interlink of Nutrient use efficiency (NUE) influenced hormone and stomatal dynamics, in enhancing photosynthesis under the co-impact of drought (D) and arsenic (As) in wheat. We analyzed how nitrogen (N) and phosphorus (P) supplementation under D+As modulates these interactions with jasmonic acid (JA) and sucrose, as central regulators. Enhanced JA by NP-enrichment reduced abscisic-acid (ABA) and salicylic-acid (SA) production to promote stomatal opening via sugar-transporter-proteins; TaSTP12, TaSTP51, and TaKAT-like1. Computational docking confirms strong interaction between JA, TaMYB84 and TaSTP’s (TaSTP12, TaSTP51) suggesting a functional complex that facilitates sucrose osmoregulation. This influences stomatal opening which promotes gas-exchange for better photosynthesis. Additionally, we highlight the correlation between stomatal dynamics and NP-use efficiency. The NP-promoted photosynthesis, phosphorus-use efficiency (PnPUE), and TaPHT1. 10 ensures Pi availability for Krebs-cycle. This improves non-photochemical quenching (NPQ), for ATP production, boosting CO2 assimilation. Moreover, the increased photosynthetic-nitrogen-use efficiency (PnNUE), along with TaNRT2.1, and TaAMT1.1 augmented rubisco activity, thereby increasing photosynthesis. NP-supplementation also boosts ASC-GSH cycle, which safeguards the rubisco enzyme and light-harvesting-complex. These processes optimize photosynthesis to maintain starch reserves and sustain wheat productivity under D+As. Our findings provide valuable insights into NP-mediated photosynthetic regulation and underscore the crucial role of NUE in optimizing this process.
Transcriptomic and OsWAK24-MPK3 crosstalk reveal resistance mechanism of primed rice seedlings against Arsenic-Iron
(Oxford University Press, 2026) Bhatia, Priyanka; Mittal, Lavanya; Pandey, Shubhangi; Khatoon, Narjis Saba; Sinha, Alok Krishna; Gupta, Meetu
Priming, elucidated as "memory," refers to the preconditioning of plant's stress responses to enhance resilience toward future stressors, including arsenic (As) contamination. This adaptive preparedness becomes further complex under As-Fe(iron) interplay, which remains scarcely delineated within priming background. Here, we employed Illumina sequencing to acquire global transcriptome alterations and heterologous interaction approach to chart the molecular reprogramming associated with As and As-Fe-dynamics in primed rice. The transcriptome revealed 3005 and 3650 genes to be differentially regulated in As and As-Fe-exposed primed seedlings. Comprehensive elucidation of expression profiling revealed that key genes were involved in transportation (OsNramp, OsFCR, OsNAS), signalling (OsWRKY, OsMYB, OsAP2, OsZF-TF), and defence (OsHSP, OsPRX, OsCyt P450). The antioxidant (OsGST, OsAPX) expression correlated well with their respective physiological enzyme activity. The entire WAK module, transducing extracellular signals to intercellular pathways, was differentially regulated under As and As-Fe influence. Notably, OsWAK24 revealed higher expression under As-Fe, reflecting its association with seedlings' tolerance behaviour. The computational protein network and docking unfolded OsMPK3 as an interactor of OsWAK24. The split-ubiquitin-based yeast-hybrid assay and immunoblot revealed OsWAK24-OsMPK3 association, suggesting OsMPK3 phosphorylates OsWAK24 at serine residue. Overall, the results decoded the seedling's resilience mechanism and aid in developing rice varieties with desired traits.