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Differential changes in grain ultrastructure, amylase, protein and amino acid profiles between Tibetan wild and cultivated barleys under drought and salinity alone and combined stress

Author:
Ahmed, Imrul Mosaddek, Cao, Fangbin, Han, Yong, Nadira, Umme Aktari, Zhang, Guoping, Wu, Feibo
Source:
Food chemistry 2013 v.141 no.3 pp. 2743-2750
ISSN:
0308-8146
Subject:
albumins, amino acid composition, amino acids, antioxidant activity, barley, cultivars, drought, drought tolerance, genotype, globulins, phenol, phytochemicals, protein content, salinity, salt tolerance, scanning electron microscopy, starch granules, ultrastructure
Abstract:
Grain phytochemical profiles were compared in Tibetan wild barley XZ5 (drought-tolerant), XZ16 (salinity/aluminum-tolerant) and cv CM72 (salinity-tolerant) in response to drought and salinity alone and combination (D+S) during anthesis. Total antioxidant capacity assessed by determining ferric-reducing antioxidant potential (FRAP) in grains increased significantly as follows: D+S>drought>salinity, and XZ5>XZ16>CM72. A marked increase in the total phenol (TP) from individual and combined stresses was observed in XZ5, while a decrease occurred in CM72. Moreover, the activity of α-/β-amylase in the grains under combined stress was 81.8%/16.9% in XZ5 and 48.6%/18.7% in XZ16 higher than that of CM72. Increases in amino acids, protein content and protein fractions of albumin, globulin, hordein and glutelin were maximised under D+S, with larger values in the Tibetan wild genotypes. Observation with a scanning electron microscopy showed a distinct genotypic difference under D+S; for example, XZ5 and XZ16 maintained a relatively integral starch granule with a greater protein deposit/matrix, while CM72 degraded by pitting. This research expands our understanding of barley drought and salt-tolerance mechanisms and provides possibility of Tibetan wild barley in developing barley cultivars with both tolerance to drought and salinity.
Agid:
600903