在高等植物中,COP1(组成型光形态发生1)充当光信号网络的中央调节剂,并通过泛素-蛋白酶体途径全局调节靶蛋白。然而,在茄科植物中,COP1相互作用蛋白在光调节果实着色和发育中的功能仍然未知。这里,COP1相互作用蛋白编码基因,SmCIP7,在茄子(SolanummelongenaL.)果实中特异性表达,被隔离。使用RNA干扰(RNAi)对SmCIP7的基因特异性沉默显着改变了果实的颜色,水果大小,果肉褐变,和种子产量。SmCIP7-RNAi果实显示明显抑制花青素和叶绿素的积累,表明SmCIP7和AtCIP7之间的功能相似性。然而,果实大小和种子产量的减少表明SmCIP7已经进化出了明显的新功能。随着HPLC-MS的广泛应用,RNA-seq,qRT-PCR,Y2H,BiFC,LCI和双荧光素酶报告系统(DLR™),研究发现,SmCIP7是光信号中的COP1相互作用蛋白,可促进花青素的积累,可能是通过调节SmTT8的转录。此外,SlFAS的同源基因SmYABBY1的急剧上调,可能是SmCIP7-RNAi茄子果实生长严重受阻的原因。总之,这项研究证明SmCIP7是调节果实颜色和发育的重要调控基因,茄子分子育种中的关键基因位点。
In higher plants, COP1 (Constitutively Photomorphogenic 1) acts as a central regulator of light-signaling networks and globally conditions the target proteins via the ubiquitin-proteasome pathway. However, the function of COP1-interacting proteins in light-regulated fruit
coloration and development remains unknown in Solanaceous plants. Here, a COP1-interacting protein-encoding gene, SmCIP7, expressed specifically in the eggplant (Solanum melongena L.) fruit, was isolated. Gene-specific silencing of SmCIP7 using RNA interference (RNAi) significantly altered fruit
coloration, fruit size, flesh browning, and seed yield. SmCIP7-RNAi fruits showed evident repression of the accumulation of anthocyanins and chlorophyll, indicating functional similarities between SmCIP7 and AtCIP7. However, the reduced fruit size and seed yield indicated SmCIP7 had evolved a distinctly new function. With the comprehensive application of HPLC-MS, RNA-seq, qRT-PCR, Y2H, BiFC, LCI, and dual-luciferase reporter system (DLR™), it was found that SmCIP7, a COP1 interactive protein in light signaling promoted anthocyanin accumulation, probably by regulating the transcription of SmTT8. Additionally, the drastic up-regulation of SmYABBY1, a homologous gene of SlFAS, might account for the strongly retarded fruit growth in SmCIP7-RNAi eggplant. Altogether, this study proved that SmCIP7 is an essential regulatory gene to modulate fruit
coloration and development, serving as a key gene locus in eggplant molecular breeding.