Three distinct rice cellulose synthase catalytic subunit genes required for cellulose synthesis in the secondary wall
Three distinct rice cellulose synthase catalytic subunit genes required for cellulose synthesis in the secondary wall
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DOI：
10.1104/pp.103.022442
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发表时间：
2003-09-01
期刊：
影响因子：
7.4
通讯作者：
Hirochika, H
中科院分区：
文献类型：
--
作者：
Tanaka, K;Murata, K;Hirochika, H
水稻（Oryza sativa）的几个脆秆突变导致植物组织的脆弱性已被遗传鉴定，但没有在分子水平上表征。我们在这里表明，负责三个不同的水稻脆性突变，诱导插入内源性反转录转座子Tos 17的基因，对应于CesA（纤维素合成酶催化亚基）基因，OsCesA 4，OsCesA 7和OsCesA 9。3个CesA基因在幼苗、秆、早熟粒和根中均有表达，但在成熟叶中不表达，且3个基因的表达谱几乎一致。三个基因的无效突变体的纤维素含量显著降低（野生型水平的8.9%-25.5%），表明这些基因不是功能冗余的。与这些结果相一致，皮层纤维细胞的细胞壁显示在所有突变体中比野生型植物中更薄。基于这些观察，纤维素合成复合物参与次生细胞壁的合成的结构进行了讨论。
Several brittle culm mutations of rice (Oryza sativa) causing fragility of plant tissues have been identified genetically but not characterized at a molecular level. We show here that the genes responsible for three distinct brittle mutations of rice, induced by the insertion of the endogenous retrotransposon Tos17, correspond to CesA (cellulose synthase catalytic subunit) genes, OsCesA4, OsCesA7 and OsCesA9. Three CesA genes were expressed in seedlings, culms, premature particles, and roots but not in mature leaves, and the expression profiles were almost identical among the three genes. Cellulose contents were dramatically decreased (8.9%-25.5% of the wild-type level) in the culms of null mutants of the three genes, indicating that these genes are not functionally redundant. Consistent with these results, cell walls in the cortical fiber cells were shown to be thinner in all the mutants than in wild-type plants. Based on these observations, the structure of a cellulose-synthesizing complex involved in the synthesis of the secondary cell wall is discussed.