冻害胁迫下小麦叶片内一些抗冻基因转录水平研究

Transcript Levels of Some Freezing-tolerant Genes in Wheat Leaves under Field Freezing Stress Conditions

研究了大田条件下,4个小麦品种幼穗发育不同阶段植株的冻害情况,并比较叶片内谷胱甘肽还原酶(GR)、抗坏血酸过氧化酶(APX)、超氧物歧化酶(SOD)和过氧化氢酶(CAT)等基因的转录水平。结果表明,幼穗发育进程慢的小麦植株受冻害较轻,其叶片内的APX和SOD基因的转录水平较高,与植株的抗冻性表现相一致,表明它们可作为评价小麦抗冻性的鉴定指标;冻害胁迫下,CAT和GR基因的转录水平与小麦植株抗冻性表现不相一致,表明这2个基因可能不适宜作为小麦抗冻性的鉴定指标。

Transcript levels of SOD（superoxide dismutase）,CAT（catalase）,APX（ascorbate peroxidase） and GR（glutathione reductase） genes were measures with RT-PCR and compared among leaves of four wheat cultivars with different development status under field freezing stress conditions.The results indicated that the spike development statuses were reversely correlated with freezing tolerance in wheat plants.During field freezing stress periods,transcript levels of SOD and APX genes were higher in leaves of wheat plants with later spike development status suffered from lower freezing injury,suggesting SOD and APX genes may take part in the freezing tolerance,and be suitable for indexes to identify the freezing tolerance in wheat.During freezing stress period,however,transcript levels CAT gene contained stable and those of GR gene increased quickly in leaves of plants with earlier spike development statuses suffered severe freezing injury,indicating that CAT and GR genes could not be positively corresponding to wheat freezing tolerance,and not fit for the indexes to identify the freezing tolerance in wheat plants.