|Author:||Simova-Stoilova, L. ; Vaseva, I. ; Grigorova, B. ; Demirevska, K. ; Feller, U.|
|Book Group Author:||NA|
The involvement of acidic proteases in soil drought response of winter wheat (Triticum aestivum L.) at seedling stage in three cultivars differing in water stress tolerance was studied. Withholding irrigation for seven days resulted in severe drought stress corresponding to 60% leaf water deficit. Stressed plants were recovered by providing optimal water supply for 3 days. Reversible changes in leaf pigment and protein content were registered, being least expressed in the drought-resistant cultivar Katya. Protein loss was inversely related to the increase in total proteolytic activity at pH 5 and in aminopeptidase activity at pH 7. Quantitative differences among the cultivars were established only for azocaseinolytic activity (pH 5). The drought-resistant cultivar (Katya) showed relatively little increase in acid protease activity whereas the highest values of this activity were detected in cultivar Pobeda. In-gel staining for cysteine-activated proteases revealed four to five separate activity bands. The upper band, specifically inhibited by E-64, was raised at severe drought. Transcript abundance of two wheat cysteine proteases - Ta.61026 putative thiol protease, and WCP2 peptidase of papain type was analyzed by RT-PCR. Gene expression of the cysteine proteases under study was suppressed in the drought-tolerant cultivar, while in the less resistant ones it remained unchanged or augmented. The results suggest that lower proteolytic activity and decreased expression of certain cysteine protease genes under water deficit during early developmental stage could be regarded as an indicator for drought resistance of winter wheat cultivars.
|Pages:||200 - 206|
|Journal:||Plant Physiology and Biochemistry|
cultivars, cysteine, drought, drought resistance, geneexpression, genes, irrigation, leaves, peptidases, plant physiology,polymerase chain reaction, protein content, proteinases, resistance,seedlings, soil, staining, stress, stress response, water deficit, waterstress, water supply, wheat, plants, Triticum, Triticum aestivum,eukaryotes, Poaceae, Cyperales, monocotyledons, angiosperms,Spermatophyta, plants, Triticum, cultivated varieties, droughttolerance, PCR, proteases, proteolytic enzymes, water supplies,watering, Plant Production (FF100), Natural Disasters (PP800),Meteorology and Climate (PP500), Environmental Tolerance of Plants(FF900), Plant Water Relations (FF062), Plant Breeding and Genetics(FF020), General Molecular Biology (ZZ360) (Discontinued March 2000),Water Resources (PP200), Plant Physiology and Biochemistry (FF060),Biotechnology (General) (WW000) (Revised June 2002) [FormerlyBiotechnology], Field Crops (FF005) (New March 2000)