ORIGINAL PAPER Ectopic overexpression of a salt stress-induced pathogenesis-related class 10 protein (PR10) gene from peanut (Arachis hypogaea L.) affords broad spectrum abiotic stress tolerance in transgenic tobacco Shalu Jain • Deepak Kumar • Mukesh Jain • Prerna Chaudhary • Renu Deswal • Neera Bhalla Sarin Received: 8 August 2011 / Accepted: 24 September 2011 Ó Springer Science+Business Media B.V. 2011 Abstract Pathogenesis-related proteins are induced in plants in response to stress, pathogen attack or abiotic stimuli, thus playing a cardinal role in plant defense system. A cDNA containing the full-length ORF, AhSIPR10 (474 bp, GenBank acc. no. DQ813661), encoding a novel Salinity-Induced PR class 10 protein was isolated from callus cell lines of peanut (Arachis hypogaea). Real-time quanti- tative reverse transcription PCR (qRT–PCR) data showed rapid upregulation of AhSIPR10 transcription in peanut callus cultures across salinity, heavy metal, cold and man- nitol-induced drought stress environments. Likewise, Ah- SIPR10 expression was also responsive towards defense/ stress signaling molecules salicylic acid (SA), methyl jasmonate, abscisic acid (ABA) and H 2 O 2 treatments. Methyl jasmonate or ABA-induced AhSIPR10 expression was, however, antagonized by SA treatment. A functional role of AhSIPR10 in alleviation of abiotic stress tolerance was further validated through its over-expression in tobacco. Analysis of T1 transgenic tobacco plants overexpressing AhSIPR10 gene showed enhanced tolerance to salt, heavy metal and drought stress through leaf disc senescence, chlorophyll content, seed set and germination assays, thus corroborating a role of salt inducible-PR10 protein in miti- gation of abiotic stress-induced damage. Transgenic tobacco lines overexpressing AhSIPR10 displayed adequate photo- synthetic CO 2 assimilation rates under salt, heavy metal and drought stress environments. Keywords Abiotic stress  Abscisic acid  Arachis hypogaea  Jasmonic acid  PR proteins  Ribonuclease  Salicylic acid Abbreviations ABA Abscisic acid AhSIPR10 Arachis hypogaea salinity-induced PR class 10 JA Jasmonic acid MeJA Methyl jasmonate MS Murashige and Skoog medium PR (10) Pathogenesis-related (class 10) SA Salicylic acid WT Wild-type Introduction Pathogenesis-related (PR) proteins are a diverse group of proteins, including chitinases, glucanases, endoproteinases and peroxidases, proteinase inhibitors, as well as small proteins such as osmotins, defensins, thionins and lipid transfer proteins (LTPs). Notably, some of the PR proteins are induced de novo upon stress, pathogen attack or abiotic S. Jain  D. Kumar  M. Jain  P. Chaudhary  N. B. Sarin (&) Plant Developmental Biology and Transformation Lab, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India e-mail: neerasarin@rediffmail.com Present Address: S. Jain Department of Plant Sciences, North Dakota State University, Fargo, ND 58102, USA Present Address: M. Jain Agronomy Department, University of Florida, Gainesville, FL 32610, USA R. Deswal Department of Botany, University of Delhi, Delhi 110007, India 123 Plant Cell Tiss Organ Cult DOI 10.1007/s11240-011-0069-6