Evolution of the leucine-rich repeat receptor-like protein kinase gene family: Ancestral copy number and functional divergence of BAM1 and BAM2 in Brassicaceae

Gene duplication allows for functional divergence and innovation that provide selective advantages. However, in flowering plants genetic studies have revealed that single-gene mutations affecting one of two or more closely related paralogs often fail to cause detectable morphological defects, suggesting functional redundancy. Flowering plants have hundreds of genes encoding leucine-rich repeat receptor-like protein kinases (LRR-RLKs), several of which play important roles in anther development but little is known about their evolutionary history and possible functional divergence. We investigated the evolutionary relationship of the LRR-RLK gene family by phylogenetic analysis and found that these closely related paralogs resulted from multiple duplication events, such as the one resulting in BAM1 and BAM2. We further used qRT-PCR to verify gene expression changes in immature anthers from the bam1/bam2 single and double mutants compared with wild type providing strong evidence that the ...

基因重复可催生功能分化与演化创新，进而赋予选择优势。然而在被子植物中，遗传学研究显示，针对两个或多个紧密相关旁系同源基因之一的单基因突变，通常无法引发可检测的形态缺陷，这提示存在功能冗余现象。被子植物拥有数百个编码富亮氨酸重复序列受体样蛋白激酶（leucine-rich repeat receptor-like protein kinases, LRR-RLKs）的基因，其中多个基因在花药发育中发挥重要作用，但目前对其演化历史及潜在功能分化的认知仍较为匮乏。本研究通过系统发育分析探究了LRR-RLK基因家族的演化关系，发现这些紧密相关的旁系同源基因源自多次基因重复事件，例如造就BAM1与BAM2的那次重复事件。我们进一步采用实时定量反转录聚合酶链反应（qRT-PCR），对bam1/bam2单突变体与双突变体的未成熟花药中的基因表达变化进行验证，并与野生型进行对比，为……提供了强有力的证据。