Wang Zhilong, Dai Liangying, Jiang Zide, Peng Wen, Zhang Lianhui, Wang Guoliang, Xie Daoxin
Institute of Molecular and Cell Biology, 61 Biopolis drive, 138673 Singapore.
Mol Plant Microbe Interact. 2005 Dec;18(12):1285-95. doi: 10.1094/MPMI-18-1285.
The F-box protein gene COI1 from Arabidopsis plays a fundamental role in response to jasmonates, which regulate plant root growth, pollen fertility, wounding and healing, and defense against pathogens and insects. Null mutations in COI1 were previously found to abolish all the jasmonate responses, and the Arabidopsis coil-1 mutant is male sterile and susceptible to pathogen infection. In this study, we isolated an F-box protein gene from soybean, which shares significant homology with the Arabidopsis COI1 and similarly contains an F-box motif and leucine rich repeats (LRR), here designated GmCOI1 (Glycine max L. (Merr.) COI1). To test whether the sequence homology and structural similarity are indicative of functional conservation, we expressed GmCOI1 in the Arabidopsis coil-1 mutant. The transgenic coil-1 plants with expression of the GmCOI1 gene were found to exhibit normal jasmonate responses, including jasmonate-regulated plant defense and fertility. In addition, the chimerical proteins with swapped domain of the F-box motif or LRR between GmCOI1 and COI1 were shown to functionally complement the coil-1 mutation. Furthermore, GmCOI1 was found to assemble into the Skpl-Cullin-F-box (SCF) complexes, similar to the formation of the Arabidopsis SCF(COO1). These data demonstrate the soybean F-box protein gene GmCOI1 is able to mediate jasmonate-regulated plant defense and fertility in Arabidopsis, which implies a generic jasmonate pathway with conserved signal components in different plant species.
拟南芥中的F-box蛋白基因COI1在茉莉酸应答中发挥着重要作用，茉莉酸可调节植物根系生长、花粉育性、创伤愈合以及对病原体和昆虫的防御。此前发现COI1的无效突变会消除所有茉莉酸应答，拟南芥coil-1突变体雄性不育且易受病原体感染。在本研究中，我们从大豆中分离出一个F-box蛋白基因，它与拟南芥COI1具有显著同源性，同样含有一个F-box基序和富含亮氨酸的重复序列（LRR），此处命名为GmCOI1（大豆COI1）。为了测试序列同源性和结构相似性是否表明功能保守，我们在拟南芥coil-1突变体中表达了GmCOI1。发现表达GmCOI1基因的转基因coil-1植株表现出正常的茉莉酸应答，包括茉莉酸调节的植物防御和育性。此外，GmCOI1和COI1之间F-box基序或LRR结构域互换的嵌合蛋白在功能上能够互补coil-1突变。此外，发现GmCOI1能组装成Skpl-Cullin-F-box（SCF）复合物，类似于拟南芥SCF(COO1)的形成。这些数据表明大豆F-box蛋白基因GmCOI1能够在拟南芥中介导茉莉酸调节的植物防御和育性，这意味着在不同植物物种中存在具有保守信号成分的通用茉莉酸途径。
