title: Nicotiana tabacum overexpressing γ-ECS exhibits biotic stress tolerance likely through NPR1-dependent salicylic acid-mediated pathway.
abstract: The elaborate networks and the crosstalk of established signaling molecules like salicylic acid (SA), jasmonic acid (JA), ethylene (ET), abscisic acid (ABA), reactive oxygen species (ROS) and glutathione (GSH) play key role in plant defense response. To obtain further insight into the mechanism through which GSH is involved in this crosstalk to mitigate biotic stress, transgenic Nicotiana tabacum overexpressing Lycopersicon esculentum gamma-glutamylcysteine synthetase (LeECS) gene (NtGB lines) were generated with enhanced level of GSH in comparison with wild-type plants exhibiting resistance to pathogenesis as well. The expression levels of non-expressor of pathogenesis-related genes 1 (NPR1)-dependent genes like pathogenesis-related gene 1 (NtPR1), mitogen-activated protein kinase kinase (NtMAPKK), glutamine synthetase (NtGLS) were significantly enhanced along with NtNPR1. However, the expression levels of NPR1-independent genes like NtPR2, NtPR5 and short-chain dehydrogenase/reductase family protein (NtSDRLP) were either insignificant or were downregulated. Additionally, increase in expression of thioredoxin (NtTRXh), S-nitrosoglutathione reductase 1 (NtGSNOR1) and suppression of isochorismate synthase 1 (NtICS1) was noted. Comprehensive analysis of GSH-fed tobacco BY2 cell line in a time-dependent manner reciprocated the in planta results. Better tolerance of NtGB lines against biotrophic Pseudomonas syringae pv. tabaci was noted as compared to necrotrophic Alternaria alternata. Through two-dimensional gel electrophoresis (2-DE) and image analysis, 48 differentially expressed spots were identified and through identification as well as functional categorization, ten proteins were found to be SA-related. Collectively, our results suggest GSH to be a member in cross-communication with other signaling molecules in mitigating biotic stress likely through NPR1-dependent SA-mediated pathway.
authors.affiliation: Plant Biotechnology Laboratory, Drug Development/Diagnostics and Biotechnology Division, Indian Institute of Chemical Biology (A unit of Council of Scientific and Industrial Research), 4, Raja S. C. Mullick Road, Kolkata 700-032, India.
authors.forename: Srijani
authors.initials: S
authors.lastname: Ghanta
authors.forename: Dipto
authors.initials: D
authors.lastname: Bhattacharyya
authors.forename: Ragini
authors.initials: R
authors.lastname: Sinha
authors.forename: Anindita
authors.initials: A
authors.lastname: Banerjee
authors.forename: Sharmila
authors.initials: S
authors.lastname: Chattopadhyay
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism; D004151:Dipeptides / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D005978:Glutathione / Q000096:biosynthesis / Q000378:metabolism; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics; D054883:Oxylipins / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D020543:Proteome; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D003517:Cyclopentanes; D004151:Dipeptides; D054883:Oxylipins; D010940:Plant Proteins; D020543:Proteome; C011006:jasmonic acid; D005978:Glutathione; C017341:gamma-glutamylcysteine; D020156:Salicylic Acid