F-box蛋白(FBP)家族在植物界中发挥着不同的功能,许多成员的功能仍未透露。在这项研究中,一种称为PmFBK2的特定FBP,包含小波儿的Kelch重复序列,在功能上进行了调查。采用酵母双杂交(Y2H)测定法,发现PmFBK2与来自P.minor的Skp1样蛋白相互作用,表明它有可能形成E3泛素连接酶,被称为SCF复合体。Y2H和共免疫沉淀测试显示PmFBK2与全长PmGID1b相互作用。这种相互作用标志着这两种蛋白质类型之间首次记录的结合,以前从未在其他植物中报道过,它们对赤霉素(GA)信号转导表现出负面影响。PmFBK2在kmd3突变体中的过表达,来自拟南芥的同源物,证明了PmFBK2恢复突变的KMD3基因的功能的能力。形态生理学和基因表达分析支持功能恢复,与kmd3突变体相比,其表现出与野生型(WT)相似的模式。有趣的是,PmFBK2或PmGID1b在拟南芥中的过表达对花环直径有相反的影响,种子重量,和植物高度。这项研究为复杂的GA信号提供了新的见解。它强调了FBP与GA受体(GID1b)之间的相互作用在调节GA反应中的关键作用。这些发现对制定策略以通过调节作物中的GA信号来增强植物生长和产量具有意义。
The F-box protein (FBP) family plays diverse functions in the plant kingdom, with the function of many members still unrevealed. In this study, a specific FBP called PmFBK2, containing Kelch repeats from Persicaria minor, was functionally investigated. Employing the yeast two-hybrid (Y2H) assay, PmFBK2 was found to interact with Skp1-like proteins from P. minor, suggesting its potential to form an E3 ubiquitin ligase, known as the SCF complex. Y2H and co-immunoprecipitation tests revealed that PmFBK2 interacts with full-length PmGID1b. The interaction marks the first documented binding between these two protein types, which have never been reported in other plants before, and they exhibited a negative effect on gibberellin (GA) signal transduction. The overexpression of PmFBK2 in the kmd3 mutant, a homolog from Arabidopsis, demonstrated the ability of PmFBK2 to restore the function of the mutated KMD3 gene. The function restoration was supported by morphophysiological and gene expression analyses, which exhibited patterns similar to the wild type (WT) compared to the kmd3 mutant. Interestingly, the overexpression of PmFBK2 or PmGID1b in Arabidopsis had opposite effects on rosette diameter, seed weight, and plant height. This study provides new insights into the complex GA signalling. It highlights the crucial roles of the interaction between FBP and the GA receptor (GID1b) in regulating GA responses. These findings have implications for developing strategies to enhance plant growth and yield by modulating GA signalling in crops.