Yangzhou University, 88 South University Avenue, Yangzhou, Jiangsu 225009, PR China.
Plant J. 2010 Aug;63(4):670-9. doi: 10.1111/j.1365-313X.2010.04271.x.
Arabidopsis seed size is regulated by the IKU pathway that includes IKU2 (a leucine-rich repeat kinase) and MINI3 (a WRKY transcription factor). We report the cloning of the IKU1 (At2g35230) gene. iku1 mutants cause reduced endosperm growth and the production of small seeds. IKU1 encodes a protein containing a VQ motif, which is a motif specific to plants. IKU1 is expressed in the early endosperm and its progenitor, the central cell. Restoration of IKU1 function in the endosperm is sufficient to rescue seed size. A genomic construct carrying mutations in the VQ motif failed to complement the iku1 mutation, suggesting an essential role for the VQ motif. IKU1 interacts with MINI3 in the yeast two-hybrid system, consistent with an IKU1 function in the IKU-MINI pathway. Our data support the proposition that endosperm development is an important determinant of seed size.
拟南芥种子大小受 IKU 途径调控，该途径包括 IKU2（富含亮氨酸重复激酶）和 MINI3（WRKY 转录因子）。我们报道了 IKU1（At2g35230）基因的克隆。iku1 突变体导致胚乳生长减少和种子变小。IKU1 编码一种含有 VQ 基序的蛋白质，该基序是植物特有的基序。IKU1 在早期胚乳及其前体中央细胞中表达。在胚乳中恢复 IKU1 的功能足以挽救种子大小。携带 VQ 基序突变的基因组构建体未能互补 iku1 突变，表明 VQ 基序的重要作用。IKU1 在酵母双杂交系统中与 MINI3 相互作用，这与 IKU1 在 IKU-MINI 途径中的功能一致。我们的数据支持胚乳发育是种子大小的一个重要决定因素的观点。
