CBP60g and CBP60h play partially redundant and critical roles in salicylic acid signaling. Arabidopsis thaliana

Our previous study on CBP60g, a calmodulin binding protein that is important for disease resistance and microbe-associated molecular pattern (MAMP)-induced SA accumulation, led to our discovery of a closely related family member CBP60h. CBP60h is also important for defense against P. syringae but is induced differently by pathogen and MAMP stimulus. Transcriptome profiling of cbp60h mutants suggested that CBP60h might be primarily functioning in response against P. syringae. We constructed a double mutant of cbp60g and cbp60h, which demonstrated severely defective defense against P. syringae and SA accumulation. Profiling of the cbp60g/h showed that its expression pattern is very similar to that of pad4. Transient expression in Tobacco showed that both CBP60g and CBP60h localized to nucleus. Our observation suggest that CBP60g and CBP60h share partially redundant but critical role in defense response and SA signaling. Overall design: This experiment consists of three biological replicates. For each genotype, two leaves per plant were pooled from three pots to prepare total RNA.

我们此前针对CBP60g——一种在抗病性及微生物相关分子模式（microbe-associated molecular pattern, MAMP）诱导的水杨酸（salicylic acid, SA）积累中发挥重要作用的钙调蛋白结合蛋白——开展的研究，使我们发现了一个与其亲缘关系密切的家族成员CBP60h。CBP60h同样在抵御丁香假单胞菌（P. syringae）的免疫防御中发挥关键功能，但对病原菌及MAMP刺激的诱导响应模式存在差异。对cbp60h突变体的转录组分析结果显示，CBP60h可能主要参与针对丁香假单胞菌的免疫应答。我们构建了cbp60g与cbp60h的双突变体，该双突变体在抵御丁香假单胞菌及SA积累方面表现出严重的防御功能缺陷。对cbp60g/h双突变体的分析表明，其表达模式与pad4极为相似。在烟草中开展的瞬时表达实验显示，CBP60g与CBP60h均定位于细胞核。我们的研究结果提示，CBP60g与CBP60h在植物防御响应及SA信号通路中存在部分功能冗余，但二者均发挥至关重要的作用。
实验整体设计：本实验包含3个生物学重复。对于每种基因型，从3个培养盆中采集每株植物的2片叶片混合以制备总RNA。