Wen F, Zhu Y, Hawes M C
Departments of Plant Pathology and Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA.
Plant Cell. 1999 Jun;11(6):1129-40. doi: 10.1105/tpc.11.6.1129.
Expression of an inducible gene with sequences common to genes encoding pectin methylesterase (PME) was found to be tightly correlated, both spatially and temporally, with border cell separation in pea root caps. Partial inhibition of the gene's expression by antisense mRNA in transgenic pea hairy roots prevented the normal separation of root border cells from the root tip into the external environment. This phenotype was correlated with an increase in extracellular pH, reduced root elongation, and altered cellular morphology. The translation product of the gene exhibited PME activity in vitro. These results are consistent with the long-standing hypothesis that the demethylation of pectin by PME plays a key role in cell wall metabolism.
研究发现，一个可诱导基因的表达在空间和时间上均与豌豆根冠中边缘细胞的分离紧密相关，该基因具有与编码果胶甲酯酶（PME）的基因共有的序列。在转基因豌豆毛状根中，反义mRNA对该基因表达的部分抑制作用阻止了根边缘细胞从根尖正常分离到外部环境中。这种表型与细胞外pH值升高、根伸长减少以及细胞形态改变相关。该基因的翻译产物在体外表现出PME活性。这些结果与长期以来的假说一致，即PME介导的果胶去甲基化在细胞壁代谢中起关键作用。
