Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, PR China.
Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, PR China.
PLoS One. 2022 Aug 19;17(8):e0267684. doi: 10.1371/journal.pone.0267684. eCollection 2022.
WRINKLED1 (WRI1) is a transcription factor which is key to the regulation of seed oil biosynthesis in Arabidopsis. In the study, we identified two WRI1 genes in rice, named OsWRI1a and OsWRI1b, which share over 98% nucleotide similarity and are expressed only at very low levels in leaves and endosperms. The subcellular localization of Arabidopsis protoplasts showed that OsWRI1a encoded a nuclear localized protein. Overexpression of OsWRI1a under the control of the CaMV 35S promoter severely retarded plant growth and development in rice. Expressing the OsWRI1a gene under the control of the P1 promoter of Brittle2 (highly expressed in endosperm but low in leaves and roots) increased the oil content of both leaves and endosperms and upregulated the expression of several genes related to late glycolysis and fatty acid biosynthesis. However, the growth and development of the transgenic plants were also affected, with phenotypes including smaller plant size, later heading time, and fewer and lighter grains. The laminae (especially those of flag leaves) did not turn green and could not unroll normally. Thus, ectopic expression of OsWRI1a in rice enhances oil biosynthesis, but also leads to abnormal plant growth and development.
WRINKLED1（WRI1）是一种转录因子，是拟南芥种子油生物合成调控的关键。在本研究中，我们在水稻中鉴定了两个 WRI1 基因，分别命名为 OsWRI1a 和 OsWRI1b，它们的核苷酸相似度超过 98%，仅在叶片和胚乳中以极低的水平表达。拟南芥原生质体的亚细胞定位表明，OsWRI1a 编码一种定位于细胞核的蛋白。在 CaMV 35S 启动子的控制下过表达 OsWRI1a 严重抑制了水稻的生长和发育。在 Brittle2 的 P1 启动子（在胚乳中高度表达，但在叶片和根中低表达）的控制下表达 OsWRI1a 基因，增加了叶片和胚乳的油含量，并上调了几个与晚期糖酵解和脂肪酸生物合成相关的基因的表达。然而，转基因植物的生长和发育也受到影响，表现为植株较小、抽穗时间较晚、穗粒数较少且较轻。叶片（尤其是旗叶）不变绿，不能正常展开。因此，OsWRI1a 在水稻中的异位表达增强了油脂的生物合成，但也导致了植物生长和发育的异常。
