Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY 14853, USA.
Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA.
New Phytol. 2011 Apr;190(1):89-100. doi: 10.1111/j.1469-8137.2010.03578.x. Epub 2010 Dec 22.
The cauliflower (Brassica oleracea var. botrytis) Orange (Or) gene affects plant growth and development in addition to conferring β-carotene accumulation. This study was undertaken to investigate the molecular basis for the effects of the Or gene mutation in on plant growth. The OR protein was found to interact with cauliflower and Arabidopsis eukaryotic release factor 1-2 (eRF1-2), a member of the eRF1 family, by yeast two-hybrid analysis and by bimolecular fluorescence complementation (BiFC) assay. Concomitantly, the Or mutant showed reduced expression of the BoeRF1 family genes. Transgenic cauliflower plants with suppressed expression of BoeRF1-2 and BoeRF1-3 were generated by RNA interference. Like the Or mutant, the BoeRF1 RNAi lines showed increased elongation of the leaf petiole. This long-petiole phenotype was largely caused by enhanced cell elongation, which resulted from increased cell length and elevated expression of genes involved in cell-wall loosening. These findings demonstrate that the cauliflower Or gene controls petiole elongation by suppressing the expression of eRF1 genes, and provide new insights into the molecular mechanism of leaf petiole regulation.
花椰菜（ Brassica oleracea var. botrytis ）橙色（ Or ）基因除了赋予β-胡萝卜素积累外，还影响植物的生长和发育。本研究旨在探讨 Or 基因突变对植物生长影响的分子基础。通过酵母双杂交分析和双分子荧光互补（ BiFC ）测定，发现 OR 蛋白与花椰菜和拟南芥真核释放因子 1-2（ eRF1-2 ）相互作用， eRF1 家族的一员。同时， Or 突变体表现出 BoeRF1 家族基因表达减少。通过 RNA 干扰生成了 BoeRF1-2 和 BoeRF1-3 表达受抑制的转基因花椰菜植株。与 Or 突变体一样， BoeRF1 RNAi 系表现出叶片叶柄伸长增加。这种长叶柄表型主要是由于细胞伸长增强所致，这是由于细胞长度增加和细胞壁松弛相关基因的表达升高所致。这些发现表明，花椰菜 Or 基因通过抑制 eRF1 基因的表达来控制叶柄伸长，为叶片叶柄调控的分子机制提供了新的见解。
