低温下冬小麦SOD及APX酶相关基因的表达分析

Expression of Genes Related to SOD and APX Enzymes in Winter Wheat at Low Temperature

为进一步揭示寒地冬小麦抗寒的生理机制,以抗寒性差异较大的"东农冬麦1号"和"中国春"为材料,测定不同低温冷冻条件下小麦超氧化物歧化酶(SOD)相关基因TSOD-1、TSOD-2、TSOD-3以及抗坏血酸过氧化物酶(APX)相关基因HAPX-1、HAPX-2、HAPX-3的表达差异。结果表明,TSOD-1、TSOD-2、TSOD-3、HAPX-2和HAPX-3基因在特定低温条件下于东农冬麦1号中的表达量明显高于中国春,而HAPX-1基因在东农冬麦1号中的表达量几乎均低于中国春。其中,TSOD-3基因在冻处理初期(低温驯化30d及-10℃2h)于东农冬麦1号中的表达量相对于中国春达到最大,分别是中国春中的8.63和11.78倍;HAPX-2和HAPX-3基因均在冷冻期(-12℃2h)于东农冬麦1号中的表达量相对于中国春达到最大,分别是中国春中的3.12和21.22倍。因此,初步推断TSOD-3、HAPX-2和HAPX-3基因是参与低温响应的重要基因。其中,TSOD-3基因在冷胁迫初期起主要作用,HAPX-2和HAPX-3基因在持续冷冻下起主要作用。

In order to clarify the expression of genes related to antioxidant enzymes under cryogenic conditions,and reveal the physiological mechanism of cold resistance in winter wheat,Dongnongdong-mai 1 and Chinese Spring,with distinguishing cold resistance were used as materials to identify the ex- pression differences of TSOD-1, TSOD-2, TSOD-3 related to superoxide dismutase（SOD） and HAPX- 1, HAPX-2, HAPX-3 related to ascorbate peroxidase（APX） under different low temperature. Results showed that, under specific low temperature treatment, the expression level of TSOD-1, TSOD-2, TSOD-3, HAPX-2 and HAPX-3 genes in Dongnongdongmai 1 were significantly higher than that in Chinese Spring,while the expression level of HAPX-1 gene in Dongnongdongmai 1 was almost lower than that in Chinese Spring. Among them,the relative expression level of TSOD-3 gene in Dongnong- dongmai 1 with respect to that in Chinese Spring reached the maximum at the beginning of the cold processing （cold acclimation 30 d,-10℃ for 2 h） ,with a ratio of 8.63 and 11.78,respectively. How- ever,the relative expression level of HAPX-2 andHAPX-2 gene in Dongnongdongmai 1 relative to that in Chinese Spring reached the maximum at the frozen period （-12℃ for 2 h） ,with a ratio of 3.12 and 21.22,respectively. It is conclued that TSOD-3, HAPX-2,and HAPX-3 genes are important genes involved in cold response. Of them,TSOD-3 gene plays a major role in the early stage of cold stress,and HAPX-2 and HAPX-3 continue to play a major role in refrigeration.