Cold and salt stress regulates the expression and activity of a chickpea cytosolic Cu/Zn superoxide dismutase

A cDNA clone encoding a cytosolic superoxide dismutase (SOD) was isolated from a cDNA library constructed from poly(A)(+)RNA from epicotyls of 5-day-old Cicer arietinum, L. etiolated seedlings after a differential screening to select clones whose expression decreases with epicotyl growth. Analysis of its deduced amino acid sequence showed all the typical structural motifs of plant cytosolic SODs (EC 1.15.1.1.). The expression of this clone is always higher in young and growing tissues than in old and storage ones, and diminishes throughout the development of the seedlings. Cytosolic Cu/Zn-SOD activity is also higher in radicles and younger internodes. Under stress conditions only cold increases the gene expression whereas the activity is clearly raised up by a saline medium. The results are discussed in relation to the gene regulation and enzyme activity control that crop plants use to resolve the different stresses that reduce their productivity. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.