Institutional Publications

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Differential regulation of nitric oxide mediated by phytoglobin1 plays a role in resistance during Botrytis cinerea infection in Arabidopsis thaliana
(Springer Nature Publishing AG, 2026) Jaiswal, Rekha; Saini, Deepak; Swain, Jagannath; Gupta, Kapuganti Jagadis
Botrytis cinerea is a prominent necrotrophic pathogen responsible for gray mold disease, affecting a wide range of plant species, including economically vital crops such as tomatoes, grapes, strawberries, etc. Nitric oxide (NO) is considered as a crucial player in plant responses to biotic stress. NO homeostasis is regulated by phytoglobin (Pgb1), a potential scavenger of NO. However, the role of the Pgb1-NO cycle in regulating defense response against B. cinerea remains largely unknown. In the current study, we investigated the defense response of Arabidopsis thaliana against B. cinerea infection using antisense (Pgb1 AS) and overexpression (Pgb1 OE) lines, which produce differential levels of NO. The Pgb1 AS line accumulated higher NO levels and conferred resistance against B. cinerea infection, with reduced ROS levels, reduced cell death, and increased stomatal closure. Conversely, Pgb1 OE showed reduced NO levels accompanied by increased susceptibility. The elevated NO level in Pgb1 AS was associated with increased nitrate reductase (NR) activity and upregulation of NIA1 and NIA2 gene expression. Interestingly, ethylene-mediated defense pathway genes such as ERF1, ACS2, and ACS6 were upregulated while pathogen-related genes such as PR1, PR2, PR5, and NPR1 were downregulated in Pgb1 AS line. The elevated expression of ethylene genes corresponded with the higher ethylene levels in Pgb1 AS. Overall, our results confirmed the crucial role of phytoglobin-modulated NO in defense against B. cinerea infection by activating the ethylene-mediated defense pathway.
N-glycan remodeling by α-D-mannosidase and β-D-N-acetylhexosaminidase regulates fruit softening, redox balance, and post-harvest pathogen resistance
(John Wiley & Sons, 2025) Irfan, Mohammad; Kumar, Pankaj; Kumar, Vinay; Ahmad, Irshad; Ansari, Sekhu; Ghosh, Sumit; Datta, Asis
Post-harvest loss of fruits and vegetables poses significant challenges to food security and economic sustainability, primarily due to ripening-associated excessive softening that shortens shelf life and increases susceptibility to pathogens. N-glycans, N-glycoproteins, and their processing enzymes are integral to various plant processes, including fruit ripening. Among these, α-D-mannosidase (α-Man) and β-D-N-acetylhexosaminidase (β-Hex) are key ripening-specific enzymes that modulate fruit softening. Previously, we have shown that RNAi-mediated suppression of α-Man or β-Hex improves fruit shelf life and firmness in both climacteric and non-climacteric fruits. However, the underlying molecular and biochemical basis of fruit softening regulation by α-Man and β-Hex was not well understood. In this study, we developed transgenic tomato (Solanum lycopersicum) plants by silencing α-Man and β-Hex simultaneously using RNAi. Suppression of these enzymes reduces N-glycoprotein degradation, downregulates pectin dissolution, and inhibits ripening-related gene expression. RNAi fruits exhibited enhanced shelf life, greater firmness, reduced reactive oxygen species (ROS) accumulation and increased resistance against post-harvest pathogens without affecting plant growth, fruit development, yield, or nutritional quality. To further explore the molecular mechanism of α-Man and β-Hex function, we purified and quantified N-glycans in RNAi fruits and other ripening-impaired mutants, identifying key N-glycan species. We also carried out iTRAQ-based quantitative proteome profiling to investigate the abundance of proteins in ripened fruit affected by silencing of α-Man and β-Hex. Molecular insights revealed that N-glycan processing and degradation are key events during ripening, influencing cell wall softening, fruit redox state, and post-harvest quality attributes. This study highlights the potential of co-silencing α-Man and β-Hex as a novel approach to extending the shelf life of fruits, regardless of their climacteric behavior, without compromising quality or yield.
Method for the measurement of ethylene during pathogen infection in arabidopsis
(Springer Nature Publishing AG, 2025) Jaiswal, Rekha; Gupta, Kapuganti Jagadis; Praveen, Afsana
Ethylene is a gaseous phytohormone that plays an important role as a signaling molecule during pathogen attack, influencing disease resistance and defense responses in plants. A precise measurement of ethylene production upon pathogen challenge is essential to elucidate its role in plant–pathogen interactions. Gas chromatography (GC) is among the most accurate and sensitive techniques for detecting and quantifying ethylene emissions due to its selectivity and effectiveness with gaseous molecules. In this chapter, we provide a detailed procedure employing GC specifically adapted for measuring ethylene levels during pathogen infection (Botrytis cinerea) in Arabidopsis leaflets. Arabidopsis leaflets infected by the necrotrophic pathogen Botrytis cinerea exhibit increased ethylene emission, facilitating the activation of defense pathways and secondary metabolites such as camalexin. The present GC method captures ethylene dynamics at early infection stages, ensuring precise quantification critical for dissecting the molecular mechanisms of plant immunity.

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