背景回顾：Cell wall expansion is a key element in determining plant morphology and growth, and cell wall integrity changes are relayed to the cell to fine-tune growth responses. 

主要发现：Here, we show that variations in the ectodomain of a cell wall-associated receptor-like kinase, WAK10, in temperate Oryza japonica accessions differentially amplify fluctuations in cell wall integrity to control rice stem height. 

结果1-WAK10基因功能：Mutation in the WAK10 gene exhibited increased cell wall thickening in stem sclerenchyma and reduced cell expansion in the stem. 

结果2-果胶寡糖-WAK10-细胞壁-株高：Two WAK10 ectodomain variants bound pectic oligosaccharides with different affinities. The pectic oligosaccharide binding regulated WAK10 phosphorylation activity, the amplitude of secondary wall deposition, and ultimately, stem height.

结果3-驯化过程中的演化：Rice population analyses revealed active enrichment of the short-stem WAK10 ectodomain alleles in japonica subspecies during domestication. 

结论：Our study outlines not only a mechanism for how variations in ligand affinities of a receptor kinase control cell wall biosynthesis and plant growth, but it also provides breeding targets for new semi-dwarf rice cultivars.

细胞壁扩张时决定植物形态和生长的关键因素，细胞壁完整性的改变会传递到细胞以精确调控植株的生长响应。本文中，作者发现在温带粳稻材料中，一个细胞壁相关类受体激酶WAK10的胞外域变异，会不同程度地放大细胞壁完整性波动，从而控制水稻的茎高。WAK10基因的突变会加强茎厚壁细胞的细胞壁增厚，并减少茎中的细胞扩张。两个WAK10胞外域变体以不同的亲和力结合果胶寡糖。果胶寡糖结合调控WAK10蛋白的磷酸化活性，次生细胞壁沉积的幅度，并最终导致株高的改变。水稻群体分析显示，短杆WAK10胞外域等位基因在粳稻亚种的驯化过程中富集。本文的研究不仅揭示了一个受体激酶的配体亲和力控制细胞壁生物合成和植物生长的机制，同时也为将来培育新的半矮秆水稻品种提供育种靶标。

** 张大兵 **