Molecular basis of Remobilization of cell wall components In culm

研究了水稻成熟期茎秆物理强度下降的生理和分子基础。经过三年的研究，取得了以下成果：1。薄壁组织细胞壁厚度随茎秆强度的降低而急剧减小.不同品种间的这种关系存在明显差异，成熟过程中非结构物质降解程度高的品种，其秆力往往会显著下降.半纤维素和果胶的含量变化较大，半纤维素是导致这种变化的主要原因。(1-3，1-4）-β-葡聚糖和阿拉伯木聚糖在水稻成熟期急剧下降.对葡聚糖酶基因的表达进行了检测，发现其表达量随着秆力的降低而增加，但品种间差异的分子基础及其随生育期的变化还有待进一步研究。

The physiological and molecular base of decreased culm physical strength in ripening stage of rice was studied. Following results were obtained during three years research ;1. Cell wall thickness of the parenchyma was sharply decreased when the strength of culm was reduced.2. Clear difference among varieties were observed in this relation and the variety showing higher remorbilization of non-structural substances during ripening tended to show remarkable reduction in culm strength.3. Hemicellulose and pectin showed the drastic change of their content and the former was responsible for this remorbilization4. (1-3, 1-4) -beta-glucan and arabinoxylan showed sharp decrease during ripening period of rice.5. Gene expression of glucanase was examined and its expression was enhanced in correspondence with the reduced culm strength.Further studies on the molecular basis of varietal differences and the change with growth stage are required.