【摘要】 采用花椰菜抗黑腐病近等基因系C731(感病系)和C712(抗病系)作为材料,利用cDNA-AFLP技术,研究了花椰菜黑腐病抗性在黑腐病菌侵染和非侵染条件下基因表达的情况.获得了两个阳性克隆M2和M6.Northern杂交和点杂交进一步证明M2是组成型表达的cDNA片段,只是在病菌侵染与非侵染条件下表达丰度不同.而M6是差异表达的cDNA片段.Southern杂交表明M6 cDNA片段在花椰菜基因组中是单拷贝序列.随后的序列分析发现M6 cDNA片段与拟南芥1号染色体的BAC F19P19中66665~66813bp有84%同源性,该片段编码拟南芥的2A6蛋白的部分序列.推测的氨基酸序列与拟南芥的2A6蛋白部分序列有91%同源性.用H2O2作为外源分子胁迫处理的初步功能分析发现:M6 cDNA片段受H2O2诱导,在诱导早期16~24h高度表达,其在叶片中的积累呈逐渐上升趋势.根据序列分析和初步的功能分析的结果推测:M6 cDNA片段可能就是编码花椰菜中类2A6蛋白的部分基因片段.是参与花椰菜抗病反应信号途径的相关调控基因片段.更多还原

【Abstract】 A near isogenic line (NIL) of Brassica oleracea var. botrytis with resistant and susceptible lines, C712 and C731, were used in this study. Differentially expressed cDNA fragments were from black rot-resistant cauliflower plants obtained using cDNA-AFLP after infection with Xanthomonas campetris pv. campetris. Thirteen of these fragments were cloned and subjected to reverse northern blot analysis using both infected and control cDNA pools. Two positive clones, M2 and M6, were isolated. Northern dot blot and northern blot analyses showed that M2 was constitutively expressed, whereas M6 contained a gene fragment that was differentially expressed during pathogen infection. Moreover, M6 cDNA fragment was also highly expressed 16～24 h after H2O2 treatment. Southern blots showed that M6 is a single copy gene in the Brassica genome, and encodes a protein with 84 % homology to 66 665～66 813 bp of BAC F19P19 on Arabidopsis Chromosome 1. The deduced M6 amino acid sequences have 91 % positive homology with the Arabidopsis 2A6 protein, which regulates ethylene synthesis. These results suggest that M6 cDNA fragment may be a regulated gene fragment associated with black rot resistance reaction signaling pathway and encoding partly 2A6-like gene fragment in cauliflower.更多还原