Donald Danforth Plant Science Center, St. Louis, Missouri 63132.
Donald Danforth Plant Science Center, St. Louis, Missouri 63132
Plant Physiol. 2020 Dec;184(4):1941-1954. doi: 10.1104/pp.20.01309. Epub 2020 Oct 20.
Heterotrimeric G-proteins are key modulators of multiple signaling and development pathways in plants and regulate many agronomic traits, including architecture and grain yield. Regulator of G-protein signaling (RGS) proteins are an integral part of the G-protein networks; however, these are lost in many monocots. To assess if the loss of RGS in specific plants has resulted in altered G-protein networks and the extent to which RGS function is conserved across contrasting monocots, we explored G-protein-dependent developmental pathways in and , representing species without or with a native RGS, respectively. Artificial microRNA-based suppression of in both species resulted in similar phenotypes. Moreover, overexpression of in resulted in phenotypes similar to the suppression of This effect of overexpression depended on its ability to deactivate Gα, as overexpression of a biochemically inactive variant protein resulted in plants indistinguishable from the wild type. Comparative transcriptome analysis of plants with suppressed levels of or overexpression of showed significant overlap of differentially regulated genes, corroborating the phenotypic data. These results suggest that despite the loss of in many monocots, the G-protein functional networks are maintained, and Gα proteins have retained their ability to be deactivated by RGS.
三聚体 G 蛋白是植物中多种信号转导和发育途径的关键调节剂，调节许多农艺性状，包括结构和谷物产量。G 蛋白信号调节蛋白（RGS）是 G 蛋白网络的一个组成部分；然而，在许多单子叶植物中这些蛋白都丢失了。为了评估特定植物中 RGS 的缺失是否导致了 G 蛋白网络的改变，以及 RGS 功能在不同单子叶植物之间的保守程度，我们分别在 和 中探索了依赖 G 蛋白的发育途径，它们分别代表没有或具有天然 RGS 的物种。在这两个物种中，基于人工 microRNA 的 抑制导致了相似的表型。此外，在 中过表达 导致的表型与 抑制的表型相似。这种 的过表达效应取决于其失活 Gα 的能力，因为过表达一种生化失活的变异蛋白导致的植物与野生型无法区分。具有抑制 或过表达 水平的 植物的比较转录组分析显示，差异调节基因有显著重叠，这与表型数据相符。这些结果表明，尽管许多单子叶植物中丢失了 ，但 G 蛋白功能网络得以维持，并且 Gα 蛋白仍然能够被 RGS 失活。
