摘要
为了从基因表达水平和抗病生理水平上了解小麦与叶锈菌互作过程中G蛋白的α、β亚基的作用,进一步揭示小麦的抗叶锈病分子机制和信号转导途径,以小麦抗叶锈病近等基因系TcLr1和叶锈菌05-22-64/05-8-63①为材料,构建了小麦与叶锈菌互作的亲和与非亲和组合,利用实时定量PCR技术对小麦G蛋白α、β亚基的基因表达量进行了检测。另外,以清水为对照,检测亲和与非亲和互作组合中,以及G蛋白抑制剂百日咳毒素PTX处理后再接种无毒性菌株的处理中,几丁质酶、β-1,3-葡聚糖酶以及活性氧产生速率的变化。结果发现,G蛋白的α亚基和β亚基都参与了小麦抗叶锈病的反应,并且可能在信号传递过程中起重要作用。无毒性叶锈菌可诱导G蛋白基因表达量的升高,而毒性叶锈菌会抑制G蛋白基因的表达。G蛋白α、β亚基在抗病反应信号传递过程中先后次序不同,β亚基基因的表达先于α亚基基因且表达量高于α亚基基因。另外,G蛋白可能通过诱导防卫酶和活性氧产生的增加来提高小麦对叶锈病的抗性。
Heterotrimeric GTP-binding protein（G protein）,a kind of protein in living cells,plays an important role in signal transduction on plasma membrane.G protein is actively involved in many physiological processes in plant,such as seed germina-tion,stem elongation,root growth,fruit development,and regulation of defense reaction system.To clarify the functions of G protein on wheat leaf rust resistance,we detected the roles of Gα and Gβ subunits at a gene expression level in the interaction between wheat（Triticum aestvum L.） and Puccinia triticina.The results may help to disclose the molecular mechanism of wheat leaf rust resistance and signal transduction.Typical compatible and incompatible interactions were constructed,from wheat leaf rust resistance near-isogenic lines TcLr1 and P.triticina 05-22-64/05-8-63①.Expression of gene encoding Gα or Gβ subunit was detected in these interactions by real-time fluorescence quantitative PCR.Using water as control,the activities of chitinase,β-1,3-glucanase,and the rate changes of reactive oxygen ions production were determined in the compatible and incompatible interactions of wheat and P.triticina,respectively.In contrast with inoculated by virulent or avirulent strain independently,wheat leaves were smeared in a thin layer by G protein inhibitor pertussis toxin and inoculated with avirulent strain after 24 h.The ex-pressions of gene for Gα and Gβ subunits were up-regulated when inoculated with the avirulent strain but down-regulated by the inoculation of the virulent strain.Different subunits of G protein showed different priorities in the process of disease resistance signal transduction.The β subunit gene expressed earlier and in a higher level than the α subunit gene.In addition,G protein in-creased the resistance to P.triticina through stimulating the defense enzyme activities and reactive oxygen ions.These results indicate that both Gα and Gβ subunits may be involved in the process of disease resistant signal transduction.
出处
《作物学报》
CAS
CSCD
北大核心
2010年第12期2028-2034,共7页
Acta Agronomica Sinica
基金
国家自然科学基金项目(30971772)
河北省教育厅基金项目(2009130)资助
作者简介
联系方式：E—mail：yangjing8171@163．com
通讯作者（Corresponding authors）：李亚宁，E-mail：yaning22@yahoo.com.cn；
通讯作者（Corresponding authors）：刘大群，E—mail：ldq@hebau．edu.cn
