Expression of a finger millet transcription factor, EcNAC1, in tobacco confers abiotic stress-tolerance.
NAC (NAM, ATAF1-2, and CUC2) proteins constitute one of the largest families of plant-specific transcription factors and have been shown to be involved in diverse plant processes including plant growth, development, and stress-tolerance. In this study, a stress-responsive NAC gene, EcNAC1, was isolated from the subtracted stress cDNA library generated from a drought adapted crop, finger millet, and characterized for its role in stress-tolerance. The expression analysis showed that EcNAC1 was highly induced during water-deficit and salt stress. EcNAC1 shares high amino acid similarity with rice genes that have been phylogenetically classified into stress-related NAC genes. Our results demonstrated that tobacco transgenic plants expressing EcNAC1 exhibit tolerance to various abiotic stresses like simulated osmotic stress, by polyethylene glycol (PEG) and mannitol, and salinity stress. The transgenic plants also showed enhanced tolerance to methyl-viologen (MV) induced oxidative stress. Reduced levels of reactive oxygen species (ROS) and ROS-induced damage were noticed in pot grown transgenic lines under water-deficit and natural high light conditions. Root growth under stress and recovery growth after stress alleviation was more in transgenic plants. Many stress-responsive genes were found to be up-regulated in transgenic lines expressing EcNAC1. Our results suggest that EcNAC1 overexpression confers tolerance against abiotic stress in susceptible species, tobacco.
Department of Crop Physiology, University of Agricultural Sciences, Bangalore, Karnataka, India.
Venkategowda
V
Ramegowda
Muthappa
M
Senthil-Kumar
Karaba N
KN
Nataraja
Malireddy K
MK
Reddy
Kirankumar S
KS
Mysore
Makarla
M
Udayakumar
D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D019295:Computational Biology; D055864:Droughts; D031748:Eleusine / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D009997:Osmotic Pressure / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D030821:Plants, Genetically Modified; D017382:Reactive Oxygen Species / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D012965:Sodium Chloride; D010269:Paraquat