FULL-LENGTH RESEARCH ARTICLE Evaluation of Differences Among Vigna aconitifolia Varieties for Acquired Thermotolerance Ramavtar Sharma • Manish Jain • Sushil Kumar • Vinod Kumar Received: 2 September 2013 / Accepted: 19 April 2014 / Published online: 21 May 2014 Ó NAAS (National Academy of Agricultural Sciences) 2014 Abstract The induction of thermotolerance using the efficacy of heat acclimation was analyzed in nine varieties of moth bean (Vigna aconitifolia Jacq.), including those derived through mutation breeding. Seedlings maintained at 27 °C were exposed to lethal temperature with or without heat-acclimation treatment. All the nine varieties sustained an abrupt rise in temperature up to 42 °C; however, 47 °C proved detrimental to all the varieties used, with CZM-99, RMB-75, and RMO-40 showing resistance. Heat acclimation followed by lethal temperature induced acquired thermo-tolerance in all the varieties except RMO-225 and RMO-435. An increase in the protein level was observed up to 37 °C, while no alteration recorded in protein content at heat-acclimation and lethal temperature. The maximum and significant increase in the level of proline content was observed in CZM-99, RMB-75, and RMO-40. Acquired thermotolerance was also found to be associated with the induction of peroxidase (POX), ascorbic peroxidase (APOX), and catalase (CAT) activities. Maximum activities of enzymes were recorded for POX at heat-acclimation temperature (42 °C), and for CAT and APOX at sub-optimal temperature (37 °C). Among all the studied enzymes, only CAT showed greater activity at lethal temperature in all the accessions except var. Jwala. Keywords Heat shock protein Á Moth bean Á Thermotolerance Á Enzyme activity Á Protein profiling Abbreviations POX: Peroxidase; APOX: Ascorbic peroxidase; CAT: Catalase; Introduction Crop production in the arid and semi-arid environments is highly unstable and unsustainable due to inhospitable climate and poor soil fertility status [32]. Therefore, it is well accepted that short duration legume crops illustrate higher and more constant yields than long-duration geno- types/crops under low rainfall conditions [25]. A similar observation has been made with moth bean (Vigna aconi- tifolia Jacq.), which is one of the most important arid legumes, known for its tolerance to drought situations. Moth bean indigenous to India is a key grain legume of arid and semi-arid ecosystem and is an indispensable compo- nent of dry land farming system of the country. It is used to make many dishes to be eaten with rice. The seeds can be cooked and eaten as a vegetable and can also be processed to preserve them for a long time. Moth seeds are fried to make them into a crunchy snack. In India, green pods are eaten as a vegetable, and the tiny seeds are eaten whole or split. A favorite Indian method of preparation is to fry the seeds in a little oil. Moth bean is known for higher R. Sharma Á M. Jain Á S. Kumar Á V. Kumar Plant Biotechnology Centre, S.K. Rajasthan Agricultural University, Bikaner 334006, India R. Sharma (&) Central Arid Zone Research Institute, Jodhpur 342003, India e-mail: ras_rau@rediffmail.com S. Kumar Department of Agricultural Biotechnology, Anand Agricultural University, Anand 388110, India V. Kumar National Research Centre on Plant Biotechnology, New Delhi 110012, India 123 Agric Res (June 2014) 3(2):104–112 DOI 10.1007/s40003-014-0108-8