Molecular Genetics, Utrecht University, Utrecht, The Netherlands.
PLoS One. 2011 Apr 21;6(4):e19028. doi: 10.1371/journal.pone.0019028.
Receptor-like kinases (RLKs) constitute a large family of signal perception molecules in Arabidopsis. The largest group of RLKs is the leucine-rich repeat (LRR) class that has been described to function in development and defense. Of these, CLAVATA1 (CLV1) and ERECTA (ER) receptors function in maintaining shoot meristem homeostasis and organ growth, but LRR RLKs with similar function in the root remain unknown. For the interaction of Arabidopsis with the oomycete pathogen Hyaloperonospora arabidopsidis the involvement of LRR RLKs has not been demonstrated. A set of homozygous T-DNA insertion lines mutated in LRR RLKs was investigated to assess the potential role of these receptors in root meristem maintenance and compatibility. One mutant line, rlk902, was discovered that showed both reduced root growth and resistance to downy mildew in a recessive manner. The phenotypes of this mutated line could not be rescued by complementation, but are nevertheless linked to the T-DNA insertion. Microarray studies showed that gene expression spanning a region of approximately 84 kb upstream of the mutated gene was downregulated. The results suggest T-DNA mediated trans-repression of multiple genes upstream of the RLK902 locus links both phenotypes.
类受体激酶（RLKs）在拟南芥中构成了信号感知分子的大家族。RLK 最大的一类是富含亮氨酸重复（LRR）家族，该家族已被描述在发育和防御中发挥作用。其中，CLAVATA1（CLV1）和 ERECTA（ER）受体在维持茎分生组织的稳态和器官生长中起作用，但在根中具有类似功能的 LRR RLK 仍未知。对于拟南芥与卵菌病原体 Hyaloperonospora arabidopsidis 的相互作用，尚未证明 LRR RLKs 的参与。一组在 LRR RLKs 中发生纯合 T-DNA 插入的突变系被调查，以评估这些受体在根分生组织维持和相容性中的潜在作用。发现一个突变系 rlk902 以隐性方式表现出根生长减少和对霜霉病的抗性。该突变系的表型不能通过互补来挽救，但与 T-DNA 插入有关。微阵列研究表明，突变基因上游约 84kb 区域的基因表达被下调。结果表明，T-DNA 介导的 RLK902 基因座上游多个基因的反式转录抑制将两种表型联系起来。
