Studies on regulatory mechanisms of cell-wall related genes involved in stem growth in plants.

植物茎的生长最终是通过细胞壁的构建和重组来优化茎内单个细胞的“延伸”和“支持”能力来调节的。调控这两种生长能力优化过程的机制尚不明确。在这项研究中，我们重点研究了两个细胞壁相关的基因家族，编码木葡聚糖内切转葡萄糖酶/水解酶的XTH和编码果胶甲基化酯酶的PME。研究发现，水稻OsXTH19基因具有水解水稻木糖葡聚糖的功能，是水稻细胞壁松动剂的候选基因。我们发现PME35基因参与了拟南芥茎原代细胞壁果胶的去甲基酯化过程，并参与了拟南芥花序茎的机械支持调控。至于调控这些细胞壁相关基因转录的因素，目前正在研究中。

Stem growth in plants is ultimately regulated through optimization of the capabilities of both “extension" and “support" of individual cells within the stem via construction and restructuring of the cell wall thereof. The mechanisms governing this optimization process of the two capabilities for the stem growth still remain elusive. In this study we focused on two cell-wall related gene families, XTH encoding xyloglucan endo transglucosylase/hydrolase and PME encoding pectin-methylesterase. We found that rice OsXTH19 gene is capable of hydrolyzing xyloglucan in rice and is a candidate for cell-wall loosening agent in rice cell wall. We demonstrated that Arabidopsis PME35 gene is required for demethylesterification of pectin in the primary cell walls of the stem, and is involved in the regulation of mechanical support of the inflorescent stem of Arabidopsis. With respect to factors governing the regulation of transcription of these cell-wall related genes are now under investigation.