钙对水稻苗期光合特性影响及其亚细胞分布

Study on the Effects of Calcium on Photosynthetic Characteristics and Its Subcellular Distribution of Rice

为了探明钙对水稻苗期光合特性影响及其在亚细胞分布的分布规律,选用高糙米钙含量品种和低糙米钙含量品种为试验材料,采用水培方法研究了钙对水稻苗期光合特性的影响及其在水稻不同类型品种中的亚细胞分布。结果表明,高钙品种的叶片净光合速率明显强于低钙品种。水稻叶片中钙含量大于根系中钙含量。在各重要细胞器组分中,钙分布表现为细胞壁>核糖体及细胞内可溶物>质体(或叶绿体)>线粒体>细胞核,细胞壁是钙最主要分布场所,细胞核、线粒体中分布较少。各细胞器中钙含量随钙处理浓度升高而增加,高钙品种表现更为明显。高钙处理对高钙品种各重要细胞器钙增加明显,推测高钙品种表现出更强的积累钙和耐受高钙胁迫能力。

To study the effects of calcium on photosynthetic characteristics and the subcellular distribution ofrice, the high-calcium in brown rice cultivars and low-calcium in brown rice cultivars were used for test. Riceplants were grown in hydroponics system to study the effects of 0.0, 0.5, 1.0, 5.0, 10.0 mg/L Ca^2 ＋onphotosynthetic characteristics and its subcellular distribution in two different types cultivars. The resultsshowed that the photosynthesis of high-calcium in brown rice cultivars was higher than that of low-calcium inbrown rice cultivars. The calcium concentrations in leaves were higher than that in roots system. Ca^2 ＋was distributed as follows cell wall 〉ribosome and the fractions of soluble component plastid（or chloroplast inleaf）〉 the fractions of nucleolus 〉mitochondrion. Ca^2＋was mostly distributed in cell wall and less distributednucleolus and mitochondrion. Ca^2 ＋concentrations were increased with increasing of Ca^2 ＋ treatment contents,especially more significantly in high-calcium in grain cultivars. Because the Ca^2＋ increase with the increase of Ca^2 ＋ treatment contents in the important organelles in high-calcium in grain cultivars was much higher, theability to absorb Ca2＋may be stronger than low-calcium in grain cultivars.