富Zn小麦品种中优耐受和富集Zn的机理研究

Study on the zinc tolerance and translocation mechanisms of “Zhongyou”,a zinc-rich wheat variety

以富Zn小麦品种"中优"为研究对象,采用水培方法,研究不同浓度梯度的Zn处理下幼苗根系细胞凋亡情况,以及地上部Zn的累积对叶片中抗氧化酶(SOD,POD,APX)活性的影响。通过RACE技术克隆到小麦HMA1(重金属ATPase1)基因的部分序列,并利用实时荧光定量PCR技术分析HMA1、HMA2、PCs(植物络合素)和MT(金属硫蛋白)基因对Zn胁迫的响应。结果如下:1)富Zn品种"中优"具有快速的向地上部转运和累积Zn的能力;2)Zn毒害导致根毛区细胞的凋亡,抑制叶片中SOD酶的活性,增加POD和APX的活性;3)HMA1,HMA2和PCs基因都受到Zn诱导表达,可能参与了Zn的吸收及向地上部的累积。

The zinc-rich wheat variety ＂Zhongyou＂was used as research material to study responses of physiological and biochemical changes at the seedling stage under Zn stress by using hydroponic cultivation. The effects of different concentrations of Zn treatments on the cell death phenomenon were observed,and the above ground tissue Zn accumulation and its effect on antioxidant system（ SOD,POD,and APX） were studied. Ta HMA1（ Heavy metal ATPase） was obtained by using 5＇and 3＇race technologies,and the expression patterns of HMA1,HMA2,PCs,and MT under Zn treatment were studied by using quantitative real-time PCR. Our results are given as follows. This variety has the ability to accumulate high-concentration Zn in above ground tissue. Zn leads to the cell death in root tissue and the inhibition of the SOD activities in leaf tissue,but improves the POD and APX activities. Ta HMA1,Ta HMA2,and PCs are induced by Zn,and they may play important roles in absorbing and accumulation of Zn in above ground tissue.