碱胁迫下不同水稻品种微观结构响应解析

Response analysis of microstructure of different rice varieties under alkali stress

研究使用质量比为1:3的Na2CO3+NaHCO3混合碱溶液(溶液质量浓度为0.20%)胁迫苗期水稻,10 d后观察分析细胞微观结构变化,以揭示不同水稻品种微观结构对碱胁迫响应机制。结果表明,不同品种对碱胁迫敏感性存在差异。碱胁迫破坏水稻根细胞排列整齐性,抑制根细胞伸长生长,对薄壁细胞抑制作用强于中柱细胞,胁迫造成部分皮层薄壁细胞崩解和部分大维管束发育不良,但胁迫促进根系木质化和枝根形成,水稻通过增加根系维管柱和大维管束直径以适应碱环境;光合色素对碱胁迫敏感性存在差异,类胡萝卜素相对叶绿素a和叶绿素b敏感性表现最弱;不同品种亚细胞结构对碱胁迫响应机制存在差异,龙粳27叶绿体、线粒体与细胞比表面积显著增加,结构和功能均受损较重,光合作用、糖类转化和运移受抑制。绥粳5号叶绿体和线粒体与细胞比表面积均显著增加,叶绿体仍具有光合功能,但光合产物运移失衡;藤系138叶绿体和线粒体与细胞比表面积均极显著下降,叶绿体结构受损,光合产物减少。越光叶绿体、线粒体和淀粉体与细胞比表面积均极显著增加,线粒体结构和功能受损较重,但叶绿体光合作用仍继续,而糖类转化和光合产物转运受阻。

In order to reveal the response mechanism of microstructure of different rice varieties to alkali stress,rice seedlings were treated with Na2CO3+NaHCO3 mixed alkali solution(mass concentration of 0.20%)at seedling stage.The results showed that the sensitivity of different varieties to alkali stress was different.Alkali stress destroyed the arrangement of rice root cells,inhibited the elongation and growth of root cells,and the inhibition of parenchyma cells was stronger than that of the middle columnar cells.The stress resulted in the disintegration of some cortical parenchyma cells and the development of some large vascular bundles,but the stress promoted the lignification of roots and the formation of branches and roots.The rice could adapt to the alkali environment by increasing the diameter of vascular column and large vascular bundle of root;photosynthetic pigment could inhibit the growth of root cells The results showed that the sensitivity of carotenoids to chlorophyll a and chlorophyll b was the weakest;the response mechanism of subcellular structure of different varieties to alkali stress was different.The specific surface area of chloroplast,mitochondria and cell of Longjing 27 increased significantly,the structure and function were damaged seriously,and photosynthesis,sugar transformation and migration were inhibited.The specific surface area of chloroplast,mitochondria and cell of Suijing 5 increased significantly,the chloroplast still had photosynthetic function,but the transportation of photosynthetic products was unbalanced;the chloroplast and the specific surface area of mitochondria and cells of rattan line 138 were significantly decreased,the chloroplast structure was damaged and the photosynthetic products were decreased.However,the ratio of photosynthesis and chloroplast structure to chloroplast was still increased.