title: Functional characterization of Nicotiana benthamiana homologs of peanut water deficit-induced genes by virus-induced gene silencing.
abstract: Determining the functional role of genes that are differentially regulated during a stress response is challenging. In this study, few water deficit-induced genes from peanut were characterized in Nicotiana benthamiana using virus-induced gene silencing (VIGS) and their relevance for stress adaptation was validated. Twenty-five cDNA clones from peanut water deficit stress-induced cDNA library that had more than 50% nucleotide similarity with N. benthamiana or tomato homologs were selected. VIGS in peanut is not yet feasible and therefore we characterized these 25 genes in N. benthamiana. Increased membrane damage was seen under water deficit stress in most of the silenced plants signifying that many of these stress-induced genes are important to confer drought tolerance. Among the genes tested, silencing by homolog of flavonol 3-O-glucosyltransferase (F3OGT), homolog of alcohol dehydrogenase, homologous to salt inducible protein, and homolog of heat shock protein 70 showed more visible wilting symptoms compared with the control plants during water deficit stress. Interestingly, down-regulation of two genes, homologous to aspartic proteinase 2, and homolog of Jumonji class of transcription factor showed relative drought tolerant phenotypes. F3OGT silenced plants showed more wilting symptoms, membrane damage and chlorophyll degradation than any other silenced plants during water deficit. Our results demonstrate that VIGS approach can be used to characterize and assess the functional relevance of water deficit stress-induced cDNAs in a heterologous species.
authors.affiliation: Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bangalore, 560 065 Karnataka, India.
authors.forename: M
authors.initials: M
authors.lastname: Senthil-Kumar
authors.forename: Geetha
authors.initials: G
authors.lastname: Govind
authors.forename: Li
authors.initials: L
authors.lastname: Kang
authors.forename: Kirankumar S
authors.initials: KS
authors.lastname: Mysore
authors.forename: M
authors.initials: M
authors.lastname: Udayakumar
mesh_terms: D000872:Anthocyanins / Q000378:metabolism; D010367:Arachis / Q000187:drug effects / Q000235:genetics*; D002734:Chlorophyll / Q000378:metabolism; D004190:Disasters; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000821:virology; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D020868:Gene Silencing / Q000502:physiology*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000821:virology; D010942:Plant Viruses / Q000502:physiology*; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000235:genetics* / Q000502:physiology / Q000821:virology; D014867:Water / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000872:Anthocyanins; D014867:Water; D002734:Chlorophyll; D005964:Glucosyltransferases; C023249:flavonol 3-O-glucosyltransferase