The Defense Effect of ABA against Turnip crinkle virus (TCV)

[ Objective ] The paper was to understand whether abscisic acid （ABA） participates the defense effect of hosts against Turnip crinkle virus （TCV）. [ Method] By external application of ABA and using the corresponding mutants, TCV coat protein levels of various plants were detected by western-blot, and the expression of defense-related genes was analyzed by RT-PCR. [Result] After external application of SA, JA, ET and ABA, only SA and ABA could significantly inhibit TCV accumulation. In arabidopsis-TCV interaction system, SA and ABA had antagonistic effect with each other, the defense effect against TCV induced by ABA was independent on SA pathway. [ Conclusion] The plants could activate distinct signal pathways to adjust the defense of hosts against virus.

BAK1在减弱拟南芥对Turnip crinkle virus感病性作用中的影响

以Turnip crinkle virus(TCV)-拟南芥(Col-0)为互作系统,研究了跨膜蛋白BAK1是否参与拟南芥对TCV的防御作用。接种试验结果表明,bak1-4突变体对TCV更加敏感,叶片易褪绿枯萎;而过量表达植株在接种TCV后受损程度较小。H2O2检测表明,严重的病症伴随有较多活性氧积累,提示该亲和互作系统中,活性氧有利于症状的形成,BAK1对活性氧产生有负调控作用。半定量RT-PCR分析表明,BAK1过表达有利于MAPK途径下游与防御相关MPK和WRKY转录因子的激活;但不影响与病程相关水杨酸途径PR1和PR2基因的表达,它们没有介导对TCV的抗性。

拟南芥BAK1基因转化及防御作用

将拟南芥BAK1基因采用Gateway方法连接到植物表达载体,通过侵花粉管进行转化,从基因和蛋白表达水平检测转化是否成功。以不同BAK1表达水平植株作为试验材料,分析BAK1在芜菁缩叶病毒(Turnip crinkle virus,TCV)-拟南芥(Col-0)亲和互作系统中对植株防御的影响。结果显示,在接种TCV后,BAK1缺陷型植株对TCV较为感病,衰老相关基因表达水平增加,表明BAK1能够增强宿主对病毒的防御作用。