Na2CO3胁迫下星星草幼苗叶绿体GST活性变化及其与相关指标的关系

通过对不同浓度Na2CO3胁迫下星星草幼苗培养基质和叶片渗透势、叶片相对电导率、叶绿体谷胱甘肽转移酶（GST）活性和O2^-产生速率的研究，以探讨星星草幼苗叶绿体GST活性在Na2CO3胁迫下的变化规律及其在抗Na2CO3胁迫中的作用。结果表明，在0～0．4％Na2CO3胁迫范围内，随着其浓度的增加星星草幼苗叶绿体GST活性增强，Na2CO3胁迫浓度继续增加则GST活性急剧减弱。星星草幼苗叶绿体GST活性随培养基质渗透势、叶片渗透势和叶片相对电导率以及叶绿体O2产生速率的变化趋势相似。叶绿体GST活性和Na2CO3胁迫浓度以及叶片渗透势之间、叶绿体GST活性和O2^-产生速率以及叶片渗透势之间、叶绿体GST活性和培养基质渗透势以及叶片渗透势之间、叶绿体GST活性和O2^-产生速率以及叶片相对电导率之间相关关系显著。说明叶绿体GST在星星草幼苗抵抗低强度（浓度）Na2CO3胁迫中起着非常重要的作用。

GST Activity and Its Related Indexes in the Chloroplasts of Puccinellia tenuiflora Seedlings under Na2CO3 Stress

The culture matrixes,leaf osmotic potentials,relative leaf conductivities,GST activities and O2^- producing rates of Puccinellia tenuiflora seedlings were studied at different Na2CO3 concentrations to probe the patterns of GST activity in the chloroplasts of P. tenuiflora seedlings under Na2CO3 stress and their effects on the resistance to Na2CO3 stress. The results showed that where the Na2CO3 concentrations changed from 0 to 4%,the GST activities in the chloroplasts of P. tenuiflora seedlings increased,but where the Na2CO3 concentrations increased beyond the concentration limits of Na2CO3,the GST activities sharply declined. The GST activities in the chloroplasts of P. tenuiflora seedlings tended to vary similarly to the matrix osmotic potentials,leaf osmotic potentials, relative leaf conductivities and chloroplast O2^- producing rates. The GST activities in the chloroplasts appeared significantly correlated with the Na2CO3 concentrations and leaf osmotic potentials,with the O2^- roducing rates and leaf osmotic potentials, with the matrix osmotic potentials and leaf osmotic potentials,and with the roducing rates and relative leaf conductivities. These revealed that chloroplast GST played a very important role in the resisting of P. tenuiflora seedlings to the of Na2CO3 at a low concentration.