摘要
采用实时荧光定量PCR技术,研究了紫云英共生表达的非特异性转脂蛋白编码基因AsE246和AsIB259在根瘤发育和固氮过程中的组织和时空表达特征,并初步考察了其在重金属镉胁迫条件下表达水平的变化。结果表明:2个目标基因仅在紫云英根瘤中特异表达,并且均在接种华癸中慢生根瘤菌7653R后22 d左右表达量达到最高。在低浓度重金属镉胁迫条件下,AsE246和AsIB259在处理早期的表达量明显升高。在低或高镉胁迫条件下,在处理中期其表达量均显著低于正常根瘤,在处理后期则维持在较低水平,表明它们参与紫云英应对镉胁迫的应答机制。
AsE246 and AsIB259 were two root nodule-specific expressed nodulin genes encoding nsLTP1 （non-specific lipid transfer protein 1）.The temporal-spatial expression characteristics of two target genes during root nodule development and nitrogen fixation process were investigated with real-time quantitative PCR.Meanwhile,the dynamic changes of expression level of target genes under heavy metal cadmium stress condition were also examined.The results showed that two target genes were strictly expressed in symbiotic organ-root nodules,and reached the peak level at about 22 days after inoculation of Mesorhizobium huakuii 7653R.It was also found that the expression levels of AsE246 and AsIB259 were significantly increased during the early stage as a response to low-level-cadmium stress.However,either at low- or high-level-cadmium stress conditions,their expression were significantly suppressed during the interim stage of Cd2＋ stress treatment comparied with those in normal nodules,and continued to maintain a relative lower level until the final stage.These indicated the two nsLTP1 genes could play a fundamental role in the response mechanism of A.sinicus to cadmium stress.In this work,some convincing data were obtained to confirm that AsE246 and AsIB259 were specific expressed nsLTP1 genes in A.sinicus root nodules.
出处
《华中农业大学学报》
CAS
CSCD
北大核心
2011年第1期18-22,共5页
Journal of Huazhong Agricultural University
基金
国家"973"计划"生物固氮作用的分子机理研究"(2010CB126500)
关键词
紫云英
转脂蛋白基因
共生体
表达特性
实时荧光定量PCR
Astragalus sinicus
lipid transfer protein encoding gene
symbiont
expression pattern
real-time qPCR
