Response of fructan metabolism in winter wheat stem to drought stress and its relationship with drought resistance
Under potted condition,two winter wheat cultivars,the drought-resistant wheat variety,'Jimai 22'('JM22'),and the water-sensitive wheat variety,'Linmai 2'('LM2'),were chosen to study the effects of drought stress on the metabolism of fructose in wheat stem and sheath from flag leaf stage to ripening stage,and its relationship with drought resistance and grain yield.The results showed drought decreased the yields of'JM22'and'LM2'by 12.8％and 36.6％,and increased the contribution rate of the dry matter stored in the stem and sheath to the grains of the wheats.During the 2nd to 5th day of drought stress,su-crose:sucrose fructosyltransferase(SST)and fructan:fructan fructosyltransferase(FFT)activity of the stem and sheath were inhibited,while fructan exohydrolase(FEH)activity was increased.At the same time,the content of fructose with polymerization(DP)≥4 fructose,and total water-soluble sugar(WSC)decreased,but the content of fructose with DP=3 increased;During the 5th to 10th day of drought stress,the contents of fructan and WSC in the stem and sheath were recovered,but the recovery magnitude of'JM22'was much greater than that of'LM2'.During the 15th to 31st day of drought resistance,drought en-hanced the activity of SST and FFT in the stem and sheath of'JM22',which promoted the accumulation of fructose with DP≥4 and DP=3.The activity of FEH of both wheat cultivars were much higher under drought condition than control during in the later stage of grain filling,which benefited the transform and output of fructan.The accumulation of H2O2 and O2-,content of MDA,the activity of SOD and CAT in wheat flag leaf increased rapidly at beginning of drought resistance,but they gradually recovered as the drought resis-tance persisted.The accumulation of H2O2 and O2-,the content of MDA,and the activity of SOD and CAT were enhanced under drought resistance at the late stage of grain filling.
NETL
NSTL
万方数据
