Reddy A R, Scheffler B, Madhuri G, Srivastava M N, Kumar A, Sathyanarayanan P V, Nair S, Mohan M
International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
Plant Mol Biol. 1996 Nov;32(4):735-43. doi: 10.1007/BF00020214.
The chalcone synthase is a key enzyme that catalyses the first dedicated reaction of the flavonoid pathway in higher plants. The chs gene and its protein product in rice has been investigated. The presence of a chalcone synthase (CHS) protein in rice seedlings and its developmental stage-specific expression has been demonstrated by western analysis. The chalcone synthase of rice was found to be immunologically similar to that of maize. A rice cDNA clone, Os-chs cDNA, encoding chalcone synthase, isolated from a leaf cDNA library of an indica rice variety Purpleputtu has been mapped to the centromeric region of chromosome 11 of rice. It was mapped between RFLP markers RG2 and RG103. RG2 is the nearest RFLP marker located at a genetic distance of 3.3 cM. Some segments of chromosome 11 of rice including chs locus are conserved on chromosome 4 of maize. The markers, including chs locus on chromosome 11 of rice are located, though not in the same order, on chromosome 4 of maize. Genetic analysis of purple pigmentation in two rice lines, Abhaya and Shyamala, used in the present mapping studies, indicated the involvement of three genes, one of which has been identified as a dominant inhibitor of leaf pigmentation. The Os-chs cDNA shows extensive sequence homology, both for DNA and protein (deduced), to that of maize, barley and also to different monocots and dicots.
查尔酮合酶是催化高等植物类黄酮途径中首个专一反应的关键酶。水稻中的chs基因及其蛋白质产物已得到研究。通过蛋白质免疫印迹分析已证实水稻幼苗中存在查尔酮合酶（CHS）蛋白及其发育阶段特异性表达。发现水稻的查尔酮合酶在免疫学上与玉米的相似。从籼稻品种Purpleputtu的叶片cDNA文库中分离出的一个编码查尔酮合酶的水稻cDNA克隆Os-chs cDNA，已被定位到水稻第11号染色体的着丝粒区域。它被定位在RFLP标记RG2和RG103之间。RG2是最近的RFLP标记，位于3.3厘摩的遗传距离处。水稻第11号染色体的一些片段包括chs基因座在玉米第4号染色体上是保守的。包括水稻第11号染色体上chs基因座在内的这些标记，虽然顺序不同，但都位于玉米第4号染色体上。在本定位研究中使用的两个水稻品系Abhaya和Shyamala中紫色色素沉着的遗传分析表明，涉及三个基因，其中一个已被鉴定为叶片色素沉着的显性抑制剂。Os-chs cDNA在DNA和蛋白质（推导）方面与玉米、大麦以及不同的单子叶植物和双子叶植物都显示出广泛的序列同源性。
