Plant Science 134 (1998) 191–197 Evidence for accumulation of a 55 kDa stress-related protein in rice and several other plant genera Ashwani Pareek 1 , Sneh Lata Singla, Anil Grover * Department of Plant Molecular Biology, Uniersity of Delhi South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi -110021, India Received 21 November 1997; received in revised form 4 February 1998; accepted 26 March 1998 Abstract Rice cells synthesize a 87 kDa protein (SAP 87) which cross-reacts with anti Neurospora crassa HSP 80 antibodies. Apart from SAP 87, we show that a polypeptide of 55 kDa of rice cross-reacts with these antibodies. This 55 kDa polypeptide is accumulated in response to high and low temperatures, salinity and desiccation stress conditions in shoots of rice seedlings. Apart from rice, Triticum aestium, Sorghum bicolor, Pisum satium, Zea mays and Brassica juncea seedlings also showed accumulation of the 55 kDa polypeptide in response to high temperature stress on Western blots. Importantly, anti human HSP 56 antibodies showed cross-reaction with a major high temperature induced 55 kDa protein of rice that matched in position to the 55 kDa protein which cross-reacted with anti N. crassa HSP 80 antibodies. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Abiotic stresses; HSP 55; Neurospora crassa ; Oryza satia ; SAP 87 1. Introduction Nearly all organisms respond to high tempera- ture by synthesizing a set of proteins called heat- shock proteins (HSPs) [1–3]. HSP 90 family proteins have been detected in several plant spe- cies, and the corresponding genes have been cloned, sequenced and characterized in a few in- stances [4–10]. Expression of HSP 90 in plants has been correlated with diverse functions such as flowering, pathogenesis, and possibly tolerance to abiotic stresses like high and low temperatures, salinity and drought [9 – 11]. While accumulation of HSPs has been related to acquisition of in- duced thermotolerance in diverse systems [12 – 14], search for the precise biochemical reactions in cells for which HSPs provide protection is contin- * Corresponding author. Tel.: +91 11 4671208; fax: +91 11 6886427/6885270; e-mail: PMB@DUSC.ernet.in 1 Present address: Department of Biology, University of North Carolina, Coker Hall, South Road, Chapel Hill, NC 27599-3280, USA. 0168-9452/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0168-9452(98)00061-2