Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China.
College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400715, People's Republic of China.
Plant J. 2022 Nov;112(4):1084-1097. doi: 10.1111/tpj.15998. Epub 2022 Oct 27.
As an important trait in crop breeding, plant height is associated with lodging resistance and yield. With the identification and cloning of several semi-dwarfing genes, increasing numbers of semi-dwarf cultivars have emerged, which has led to a 'green revolution' in rice (Oryza sativa) production. In this study, we identified a rice semi-dwarf mutant, semi-dwarf 38 (sd38), which showed significantly reduced cell length. SD38 encodes a fatty acid elongase, β-ketoacyl-CoA synthase, which is involved in the synthesis of very-long-chain fatty acids (VLCFAs). Expression analysis showed that SD38 was localized on the membrane of the endoplasmic reticulum, and was expressed in all analyzed tissues with differential abundance. The mutation of SD38 affected lipid metabolism in the sd38 mutant. A functional complementarity test in Saccharomyces cerevisiae indicated that SD38 was capable of complementing the deficiency of ELO3p activity in BY4741-elo3 knockout yeast cells by participating in the synthesis of C24:0 VLCFA. Significant changes were observed in the expression of genes involved in ethylene synthesis, which resulted in reduced content of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) in the sd38 mutant. Exogenously supplied VLCFA (C24:0) increased the expression levels of OsACS3, OsACS4, and OsACO7 and the plant height of sd38 mutant seedlings, similar to the effect of exogenous application of ACC and ethephon. These results reveal a relationship among VLCFAs, ethylene biosynthesis, and plant height and improve our understanding of plant height development in crops.
作为作物育种中的一个重要性状，株高与抗倒伏性和产量有关。随着几个半矮化基因的鉴定和克隆，越来越多的半矮化品种出现，这导致了水稻（Oryza sativa）生产的“绿色革命”。在这项研究中，我们鉴定了一个水稻半矮化突变体 sd38，其细胞长度显著减小。SD38 编码脂肪酸延长酶，β-酮酰基辅酶 A 合酶，该酶参与非常长链脂肪酸（VLCFAs）的合成。表达分析表明，SD38 定位于内质网膜上，并在所有分析的组织中以不同丰度表达。SD38 的突变影响 sd38 突变体中的脂质代谢。在酿酒酵母中的功能互补性测试表明，SD38 能够通过参与 C24:0 VLCFA 的合成来弥补 BY4741-elo3 敲除酵母细胞中 ELO3p 活性的缺乏。参与乙烯合成的基因表达发生显著变化，导致 sd38 突变体中乙烯前体 1-氨基环丙烷-1-羧酸（ACC）的含量降低。外源性 VLCFA（C24:0）增加了 sd38 突变体幼苗中 OsACS3、OsACS4 和 OsACO7 的表达水平，并类似于外源施用 ACC 和乙烯膦的效果。这些结果揭示了 VLCFAs、乙烯生物合成和株高之间的关系，提高了我们对作物株高发育的理解。
