外源ABA对苗期低温下冬小麦蔗糖含量及其关键酶基因表达的影响

Effect of Exogenous Abscisic Acid on Sucrose Content and Expression of Key Enzyme Genes Controlling Sucrose Metabolism in Seedling Period of Winter Wheat under Cold Stress

为了探讨外源ABA对苗期低温下冬小麦植株蔗糖代谢的调节作用,以抗寒性强的品种东农冬麦1号和抗寒性弱的品种济麦22为试验材料,在三叶期分别于不同温度下经ABA处理48 h后取叶片和地下茎,研究外源ABA对苗期低温下冬小麦的蔗糖含量及蔗糖代谢相关酶基因表达的影响。结果表明,外源ABA处理使低温下抗寒性强的东农冬麦1号中积累了更多的蔗糖,尤其是叶片,而在济麦22中则抑制了蔗糖的积累。4℃以上温度时,外源ABA促进了东农冬麦1号叶片和地下茎中UGP在蔗糖合成中的作用;在4℃以下低温时,外源ABA则促进了UGP在蔗糖分解中的作用。4℃以上温度时,外源ABA提高了东农冬麦1号叶片中Ta SPS基因和地下茎中Ta SAInv基因的表达,而抑制了济麦22各器官中Ta SPS基因和Ta SAInv基因的表达。此外,4℃以上温度时,外源ABA抑制了两个小麦品种各器官中Ta SS基因的表达。表明抗寒性强的东农冬麦1号对外源ABA可能更加敏感,其蔗糖合成能力的提高将有利于冬小麦植株抵御低温,进而维持植株的存活。

To discuss the regulation of exogenous ABA on sucrose metabolism in seedling stage of winter wheat,two winter wheat cultivars Dongnongdongmai 1 with strong cold resistance and Jimai 22 with weak cold resistance were used as materials. The leaves were sprayed with ABA at trefoil stage. Leaves and underground stems were collected to study the effects of exogenous ABA on sucrose content and expression of key enzyme genes controlling sucrose metabolism. The results indicated that with the temperature decrease in seedling stage,Dongnongdongmai 1 accumulated more sucrose with exogenous ABA,especially in leaves,while the sucrose content was inhibited by exogenous ABA in Jimai 22. With the treatment of exogenous ABA,UGP played a major role in the synthesis of sucrose at the temperature above 4 ℃,and played a major role in the decomposition of sucrose at the temperature below 4 ℃. The expression of Ta SPS gene in leaves and Ta SAInv gene in underground stems of Dongnongdongmai 1 were promoted by exogenous ABA at the temperature above 4 ℃,but the expression of Ta SPS and Ta SAInv genes were inhibited by exogenous ABA in two organs of Jimai 22.The expression of Ta SS genes in different organs of two wheat varieties were inhibited by exogenous ABA. It showed that Dongnongdongmai 1 with strong cold resistance could be more sensitive to exogenous ABA. The ability of sucrose synthesis will help to resist the low temperature and maintain the plant survival.