Maternal control of seed size by EOD3/CYP78A6 in Arabidopsis thaliana
Maternal control of seed size by EOD3/CYP78A6 in Arabidopsis thaliana
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拟南芥中 EOD3/CYP78A6 对种子大小的母体控制
DOI：
10.1111/j.1365-313x.2012.04907.x
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发表时间：
2012-06-01
期刊：
影响因子：
7.2
通讯作者：
Li, Yunhai
中科院分区：
文献类型：
--
作者：
Fang, Wenjuan;Wang, Zhibiao;Li, Yunhai
高等植物的种子大小是由胚胎、胚乳和母体组织的生长协调决定的，但对最终种子大小的遗传和分子机制知之甚少。我们之前已经证明，拟南芥DA1在母系中起控制种子大小的作用，DA1 -1突变体比野生型产生更大的种子。通过对da1-1修饰子的激活标记，我们确定了da1-1种子大小的增强子（eod3-1D）。EOD3编码拟南芥细胞色素P450/CYP78A6，在大多数植物器官中表达。EOD3的过表达显著增加了野生型植物的种子大小，而EOD3 -ko功能缺失突变体形成小种子。CYP78A9是最密切相关的家族成员，其破坏可协同增强EOD3 -ko突变体的种子大小表型，表明EOD3与CYP78A9一起冗余作用，影响种子生长。正交实验表明，EOD3母系对种子生长有促进作用。双突变体eod3-ko cyp78a9-ko在发育中的种子母系被毛中具有较小的细胞，而eod3-1D在被毛中形成更多更大的细胞。遗传分析表明，EOD3独立于母系因子DA1和TTG2影响种子生长。总的来说，我们的研究结果确定了EOD3是种子大小控制的一个因素，并为植物如何控制种子大小提供了见解。
Seed size in higher plants is coordinately determined by the growth of the embryo, endosperm and maternal tissue, but relatively little is known about the genetic and molecular mechanisms that set final seed size. We have previously demonstrated that Arabidopsis DA1 acts maternally to control seed size, with the da1-1 mutant producing larger seeds than the wild type. Through an activation tagging screen for modifiers of da1-1, we have identified an enhancer of da1-1 (eod3-1D) in seed size. EOD3 encodes the Arabidopsis cytochrome P450/CYP78A6 and is expressed in most plant organs. Overexpression of EOD3 dramatically increases the seed size of wild-type plants, whereas eod3-ko loss-of-function mutants form small seeds. The disruption of CYP78A9, the most closely related family member, synergistically enhances the seed size phenotype of eod3-ko mutants, indicating that EOD3 functions redundantly with CYP78A9 to affect seed growth. Reciprocal cross experiments show that EOD3 acts maternally to promote seed growth. eod3-ko cyp78a9-ko double mutants have smaller cells in the maternal integuments of developing seeds, whereas eod3-1D forms more and larger cells in the integuments. Genetic analyses suggest that EOD3 functions independently of maternal factors DA1 and TTG2 to influence seed growth. Collectively, our findings identify EOD3 as a factor of seed size control, and give insight into how plants control their seed size.