Expression of dehydration-stress-related genes in the crowns of wheatgrassspecies [Lophopyrum elongatum (Host) A. Love and Agropyron desertorum (Fisch ex Link.) Schult.] having contrasting acclimation to salt, cold and drought

Agropyron desertorum and Lophopyrum elongatum were grown in a control envir onment or acclimated in high-salt (daily exposure to 75 or 150 mM NaCl for 6 d), cold (6/2 degrees C for 14 d) or drought environments (watering withh eld for 6 d), Lophopyrum elongatum was constitutively tolerant to salt and also acclimated more to salt than did A. desertorum whereas A. desertorum a cclimated more to cold and drought. Dehydrin and non-specific lipid transfe r protein (nsLTP) mRNA sequences and polypeptides increased more, during ac climation to cold and drought, in A. desertorum than in L. elongatum crowns . Expression of immunologically identified dehydrin polypeptides was much h igher in drought-acclimated A. desertorum than in any other species/treatme nt combination, The most strongly expressed were 42 and 20 kDa, No change i n dehydrin or nsLTP polypeptides were detected in the crowns during acclima tion to salt. Overall, there was stronger acclimation to dehydrative stress es, at the molecular level, in A. desertorum than in L. elongatum crowns. D ifferences in dehydrin and nsLTP mRNA and polypeptide expression during acc limation to different stresses indicated that plants sense the differences between different primary potential causes of cellular dehydration.