AtsHsp17.6-CⅠ和AtsHsp17.6-CⅡ基因对非生物胁迫的应答研究

Response of AtsHsp17.6-CⅠ and AtsHsp17.6-CⅡ of Arabidopsis thaliana L.to Abiotic Stress

小分子热激蛋白是植物受到热胁迫后的主要表达产物之一,与植物细胞耐热有密切关系。该研究发现,拟南芥小分子热激蛋白基因AtsHsp17.6-CⅠ和AtsHsp17.6-CⅡ除热激之外,重金属离子Ni+、Pb2+、Cu2+、Zn2+和Al3+均能诱导这2个热激蛋白基因的表达;氧化胁迫和渗透胁迫同样也能诱导它们表达。该研究将由CaMV35S启动子驱动的这2个小分子热激蛋白基因导入拟南芥,RT-PCR分析表明,2个小分子热激蛋白基因在转基因植物中呈现组成型表达。实验结果表明,组成型表达小分子热激蛋白基因AtsHsp17.6-CⅠ的转基因植物表现出对6μmol.L-1Cd2+胁迫、0.4%NaCl胁迫的耐受性。研究表明,这2个小分子热激蛋白基因可能参与着多种抗逆途径,推测其能够减轻或抵抗逆境胁迫引起的伤害并对其进行修复。

Small heat shock proteins are main products of plants under heat shock stress and have close relation- ships to the thermotolerance of plant cells. It was showed that two small heat shock protein genes of Arabidopsis thaliana L. , AtsHspl7.6-C I and AtsHsp17.6-C Ⅱ also can be induced by other heavy metal ions, such as Ni ＋ , Pb2＋ , Cu2＋ ： Zn2＋ , Al3＋ , etc. Osmotic and oxidative stress can also induce their expression. Two kinds of con- structions with the two genes under the control of the cauliflower mosaic virus 35S promoter, were induced into the genome of A. thaliana L. respectively. RT-PCR analysis indicated that the constitutive expression of the two genes in transgenic plants. It was showed that AtsHsp17. 6-C II gene was over-expressed in A. thaliana, the transgenic plants have acquired stress-tolerance to 6 μmol · L^-1 Cd2＋ and 0.4% NaCl. Thus, they appear to play major role in maintaining cell function and survival during multiple stress or facilitating recovery from stress.