Stem cell homeostasis is pivotal for continuous and programmed formation of organs in plants. The precise control of meristem proliferation is mediated by the evolutionarily conserved signaling that encompasses complex interactions among multiple peptide ligands and their receptor-like kinases. Here, we identified compensation mechanisms involving the CLAVATA1 (CLV1) receptor and its paralogs, BARELY ANY MERISTEMs (BAMs), for stem cell proliferation in two Solanaceae species, tomato, and groundcherry. Genetic analyses of higher-order mutants deficient in multiple receptor genes, generated via CRISPR-Cas9 genome editing, reveal that tomato SlBAM1 and SlBAM2 compensate for slclv1 mutations. Unlike the compensatory responses between orthologous receptors observed in Arabidopsis, tomato slclv1 mutations do not trigger transcriptional upregulation of four SlBAM genes. The compensation mechanisms within receptors are also conserved in groundcherry, and critical amino acid residues of the receptors associated with the physical interaction with peptide ligands are highly conserved in Solanaceae plants. Our findings demonstrate that the evolutionary conservation of both compensation mechanisms and critical coding sequences between receptor-like kinases provides a strong buffering capacity during stem cell homeostasis in tomato and groundcherry.

中文翻译：

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茄科植物干细胞稳态受体补偿的进化保守性

干细胞稳态对于植物器官的连续和程序化形成至关重要。分生组织增殖的精确控制是由进化上保守的信号传导介导的，该信号传导涵盖多种肽配体及其受体样激酶之间的复杂相互作用。在这里，我们确定了涉及 CLAVATA1 (CLV1) 受体及其旁系同源物、几乎没有分生组织 (BAM) 的补偿机制，用于两种茄科物种（番茄和地樱桃）的干细胞增殖。通过 CRISPR-Cas9 基因组编辑生成的缺乏多个受体基因的高阶突变体的遗传分析表明，番茄 SlBAM1 和 SlBAM2 补偿了 slclv1 突变。与拟南芥中观察到的直系同源受体之间的补偿反应不同，番茄 slclv1 突变不会触发四个 SlBAM 基因的转录上调。受体内的补偿机制在地樱桃中也很保守，并且与肽配体物理相互作用相关的受体的关键氨基酸残基在茄科植物中高度保守。我们的研究结果表明，受体样激酶之间的补偿机制和关键编码序列的进化保守性在番茄和地樱桃的干细胞稳态过程中提供了强大的缓冲能力。