氯霉素处理对拟南芥STN7和STN8基因表达的影响

Expression of STN7 and STN8 Genes in Arabidopsis with CAP Treatment

本实验运用多肽抗体、磷酸化抗体和半定量RT-PCR技术,研究了叶绿体蛋白合成抑制剂——氯霉素(CAP)处理对拟南芥叶片在生长光强下LHCⅡ蛋白与PSⅡ核心蛋白的磷酸化、STN7和STN8基因在mRNA水平和蛋白水平的变化.结果显示:与对照相比,CAP处理叶片在生长光强下STN7基因表达的mRNA水平减少,类囊体膜上酶蛋白含量较低,LHCⅡ蛋白磷酸化水平也较低;而STN8基因表达的mRNA水平增加,类囊体膜上酶蛋白含量增加了1倍,与PSⅡ核心蛋白中D1、D2和CP43的磷酸化水平较高相吻合.研究表明,氯霉素抑制叶绿体蛋白合成后并影响核基因STN7和STN8的表达.

In this paper,we investigated the phosphorylation levels of LHCⅡ and PSⅡ core proteins,the mRNA and the protein levels of STN7 and STN8 genes in chloramphenicol （CAP,which is a inhibitor of the chloroplast protein synthesization ） treated Arabidopsis leaves,using polypeptide antibody,P-Thr antibody and RT-PCR.The results showed that in CAP-treated leaves with growth illumination intensity,the mRNA level of STN7 was reduced and the enzyme content in thylakoid membrane was lower than that of control.The phosphorylation level of LHCⅡ was significantly lower comparing with control;on the contrary,the mRNA level of STN8 gene was increased,the enzyme content in thylakoid membrane was increased one fold.This was in accordance with the high phosphorylation level in PSⅡcore protein.These results indicated that CAP inhibited synthesization of chloroplast protein,followed by affecting the expression of the nuclear-encoded genes STN7 and STN8.