Li Yan, Xing Minghui, Yang Qiu, Wang Yong, Jiang Jun, Zhao Yingkai, Zhao Xiangmei, Shen Aimin, Feng Youwei, Zhao Xuejie, Zhao Qing, Hu Chunhua, Wang Yunxing, Zhang Bing, Zhou Shifeng, Gu Huihui, Huang Jinyong, Zhang Yanjie
School of Agricultural Sciences, Zhengzhou University, Kexue Avenue 100, Zhengzhou 450001, China.
School of Agricultural Sciences, Zhengzhou University, Kexue Avenue 100, Zhengzhou 450001, China; State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, 475001, Kaifeng, China.
Int J Biol Macromol. 2023 Apr 15;234:123729. doi: 10.1016/j.ijbiomac.2023.123729. Epub 2023 Feb 19.
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.
在高等植物中，CONSTITUTIVELY PHOTOMORPHOGENIC 1（COP1）作为光信号网络的核心调节因子，并通过泛素-蛋白酶体途径全局性地调控靶蛋白。然而，在茄科植物中，与COP1相互作用的蛋白在光调控果实着色和发育中的功能仍不清楚。在此，分离出一个在茄子（Solanum melongena L.）果实中特异性表达的与COP1相互作用的蛋白编码基因SmCIP7。利用RNA干扰（RNAi）对SmCIP7进行基因特异性沉默显著改变了果实着色、果实大小、果肉褐变和种子产量。SmCIP7-RNAi果实中花青素和叶绿素的积累明显受到抑制，表明SmCIP7与AtCIP7具有功能相似性。然而，果实大小和种子产量的降低表明SmCIP7已经进化出一种全新的功能。通过高效液相色谱-质谱联用（HPLC-MS）、RNA测序（RNA-seq）、实时定量聚合酶链反应（qRT-PCR）、酵母双杂交（Y2H）、双分子荧光互补（BiFC）、荧光素酶互补成像（LCI）和双荧光素酶报告系统（DLR™）的综合应用，发现光信号转导中的COP1相互作用蛋白SmCIP7可能通过调节SmTT8的转录促进花青素积累。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，本研究证明SmCIP7是调控果实着色和发育的必需调控基因，是茄子分子育种中的关键基因位点。
