Duan Meijuan, Sun Samuel S M
Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, PR China.
Plant Mol Biol. 2005 Sep;59(1):165-78. doi: 10.1007/s11103-004-7507-3.
Rice provides a staple source of energy, protein and other nutrients to half of the world population. Over 90 of the rice seeds consists of starch and protein by dry weight. The quantity and property of starch and protein thus play a dominant role in the yield and quality of rice. The amylase content of starch is a determining factor in the eating and cooking quality while the amount and essential amino acids balance of storage proteins affect the nutritional quality of rice. In China, the super-hybrid rice currently under the last phase of development has a 35 yield advantage over the best inbred rice varieties. However, its grain quality needs further improvement. This study reported the expression patterns of 44 genes participating in starch, storage protein, and lysine synthesis in the developing rice grain. Field grown rice cultivar 9311, the paternal line of an elite super-hybrid rice LYP9 with its draft genomic sequence released, was used as plant material. Results revealed diverse yet coordinated expression profiles of the genes involved in the three pathways which lead to the final composition and property of starch, protein and lysine that determine the quality of rice, providing useful information for rice quality improvement.
水稻为世界一半人口提供了主要的能量、蛋白质和其他营养来源。按干重计算，超过90%的水稻种子由淀粉和蛋白质组成。因此，淀粉和蛋白质的数量及特性对水稻的产量和品质起着主导作用。淀粉的淀粉酶含量是影响食用和蒸煮品质的决定性因素，而贮藏蛋白的含量和必需氨基酸平衡则影响水稻的营养品质。在中国，目前处于最后开发阶段的超级杂交水稻比最好的常规水稻品种具有35%的产量优势。然而，其稻米品质仍需进一步改善。本研究报道了44个参与水稻籽粒发育过程中淀粉合成、贮藏蛋白合成和赖氨酸合成相关基因的表达模式。以田间种植的水稻品种9311为材料，它是优良超级杂交水稻LYP9的父本，其基因组序列草图已公布。结果揭示了参与这三条途径的基因具有多样但协调的表达谱，这些途径最终决定了淀粉、蛋白质和赖氨酸的组成及特性，而这些物质决定了水稻的品质，为改善水稻品质提供了有用信息。
