Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
Plant Resilience Institute, Michigan State University, East Lansing, Michigan 48824, USA.
Plant Physiol. 2023 Jan 2;191(1):643-659. doi: 10.1093/plphys/kiac486.
To cope with environmental stresses and ensure maximal reproductive success, plants have developed strategies to adjust the timing of their transition to reproductive growth. This has a substantial impact on the stress resilience of crops and ultimately on agricultural productivity. Here, we report a previously uncharacterized, plant-specific gene family designated as Regulator of Flowering and Stress (RFS). Overexpression of the BdRFS gene in Brachypodium distachyon delayed flowering, increased biomass accumulation, and promoted drought tolerance, whereas clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated knockout mutants exhibited opposite phenotypes. A double T-DNA insertional mutant in the two Arabidopsis (Arabidopsis thaliana) homologs replicated the effects on flowering and water deprivation seen in the B. distachyon CRISPR knockout lines, highlighting the functional conservation of the family between monocots and dicots. Lipid analysis of B. distachyon and Arabidopsis revealed that digalactosyldiacylglycerol (DGDG) and phosphatidylcholine (PC) contents were significantly, and reciprocally, altered in overexpressor and knockout mutants. Importantly, alteration of C16:0-containing PC, a Flowering Locus T-interacting lipid, associated with flowering phenotype, with elevated levels corresponding to earlier flowering. Co-immunoprecipitation analysis suggested that BdRFS interacts with phospholipase Dα1 as well as several other abscisic acid-related proteins. Furthermore, reduction of C18:3 fatty acids in DGDG corresponded with reduced jasmonic acid metabolites in CRISPR mutants. Collectively, we suggest that stress-inducible RFS proteins represent a regulatory component of lipid metabolism that impacts several agronomic traits of biotechnological importance.
为了应对环境压力并确保最大的繁殖成功，植物已经发展出策略来调整其向生殖生长过渡的时间。这对作物的应激弹性有重大影响，并最终对农业生产力产生影响。在这里，我们报告了一个以前未被描述的、植物特异性的基因家族，称为开花和应激调节因子（RFS）。在拟南芥中过表达 BdRFS 基因会延迟开花、增加生物量积累并促进耐旱性，而聚类规则间隔短回文重复/CRISPR 相关蛋白 9（CRISPR/Cas9）介导的敲除突变体则表现出相反的表型。在两个拟南芥（Arabidopsis thaliana）同源物中的双 T-DNA 插入突变体复制了在 B. distachyon CRISPR 敲除系中观察到的开花和水分胁迫的影响，突出了该家族在单子叶植物和双子叶植物之间的功能保守性。B. distachyon 和拟南芥的脂质分析表明，二半乳糖基二酰基甘油（DGDG）和磷脂酰胆碱（PC）含量在过表达和敲除突变体中显著且相互改变。重要的是，改变含有 C16:0 的 PC，即开花位点 T 相互作用脂质，与开花表型相关，高水平对应于更早的开花。共免疫沉淀分析表明，BdRFS 与磷脂酶 Dα1 以及其他几种与脱落酸相关的蛋白质相互作用。此外，DGDG 中 C18:3 脂肪酸的减少与 CRISPR 突变体中茉莉酸代谢物的减少相对应。总之，我们认为应激诱导的 RFS 蛋白代表了影响生物技术重要的几个农艺性状的脂质代谢的调节成分。
