The tobacco plastid accD gene is essential and is required for leaf development
The tobacco plastid accD gene is essential and is required for leaf development
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DOI：
10.1111/j.1365-313x.2005.02533.x
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发表时间：
2005-10-01
期刊：
影响因子：
7.2
通讯作者：
Day, A
中科院分区：
文献类型：
--
作者：
Kode, V;Mudd, EA;Day, A
被子植物质体基因组通常编码大约80种多肽，主要用于确定质体定位的功能，如光合作用和基因表达。质体蛋白质的合成和质体clpP 1基因的表达对烟草的发育是必不可少的，这表明存在一个或多个质体基因，其影响超出了质体区室。质体accD基因编码乙酰辅酶A羧化酶的β-羧基转移酶亚基，并且存在于大多数开花植物的质体中，包括非光合寄生植物。我们使用同源重组将野生型accD基因替换为aadA破坏的突变等位基因。抗生素存在下的持续异质性表明野生型accD等位基因是必不可少的。在不存在抗生素的情况下生长的质体转化体中揭示了accD敲除的表型。叶片含有淡绿色扇区，由于细胞分裂停滞或损失而缺少部分或全部叶片。异常结构存在于突变体植物中发现的质体中，表明可能需要accD来维持质体隔室。预计质体区室的丧失将是致命的。这些结果提供了遗传证据，显示了质体ACCase在导致叶发育所需的质体外过程所需的产物合成的途径中的重要作用。
Angiosperm plastid genomes typically encode approximately 80 polypeptides, mainly specifying plastid-localized functions such as photosynthesis and gene expression. Plastid protein synthesis and expression of the plastid clpP1 gene are essential for development in tobacco, indicating the presence of one or more plastid genes whose influence extends beyond the plastid compartment. The plastid accD gene encodes the beta-carboxyl transferase subunit of acetyl-CoA carboxylase and is present in the plastids of most flowering plants, including non-photosynthetic parasitic plants. We replaced the wild-type accD gene with an aadA-disrupted mutant allele using homologous recombination. Persistent heteroplasmy in the presence of antibiotics indicated that the wild-type accD allele was essential. The phenotype of the accD knockout was revealed in plastid transformants grown in the absence of antibiotics. Leaves contained pale green sectors and lacked part or all of the leaf lamina due to arrested division or loss of cells. Abnormal structures were present in plastids found in mutant plants, indicating that accD might be required to maintain the plastid compartment. Loss of the plastid compartment would be expected to be lethal. These results provide genetic evidence showing the essential role of plastid ACCase in the pathway leading to the synthesis of products required for the extra-plastidic processes needed for leaf development.