Yuan Xing, Quan Shaowen, Liu Jinming, Guo Caihua, Zhang Zhongrong, Kang Chao, Niu Jianxin
Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China.
Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China; Xinjiang Production and Construction Corps Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization, Shihezi 832003, Xinjiang, China.
Int J Biol Macromol. 2022 Dec 31;223(Pt A):202-212. doi: 10.1016/j.ijbiomac.2022.11.004. Epub 2022 Nov 5.
Phosphatidyl ethanolamine-binding protein (PEBP) has a conserved PEBP domain and plays an important role in regulating the flowering time and growth of angiosperms. To understand the evolution of PEBP family genes in walnut family and the mechanism of regulating flowering in photoperiod pathway, 53 genes with PEBP domain were identified from 5 Juglandaceae plants. The PEBP gene family of Juglandaceae can be divided into four subgroups, FT-like, TFL-like, MFT-like and PEBP-like subgroups. These genes all show very high homology for motifs and gene structure in Juglandaceae. In addition, the results of gene replication and collinearity analysis showed that the evolution of PEBP genes was mainly purified and selected, and segmental repetition was the main driving force for the evolution of PEBP gene family in walnut family. We found that PEBP gene family played an important role in female flower bud differentiation, and most JrPEBP genes were highly expressed in leaf bud and female flower bud by qRT-PCR. In Arabidopsis, AtCO can not only directly bind to CORE2, but also interact with NF-Y complex to positively regulate the expression of AtFT gene. In this study, we proved that JrCO (the lineal homologue of AtCO) could not directly regulate the expression of JrFT gene, but could enhance the binding of JrNF-YB4/6 protein to the promoter of JrFT gene by forming a heteropolymer with NF-YB4/NF-YB6. We also confirmed that JrNF-YC1/3/7, JrNF-YB4/6 and JrCO can form a trimer structure similar to AtNF-YB-YC-CO of Arabidopsis, and then bind to the promoter of JrFT gene to promote the transcription of JrFT gene. In a word, through identification and analysis of PEBP gene family in Juglandaceae and study on the mechanism of photoperiod pathway regulating flowering in walnut, we have found that nuclear transcription factor NF-YB/YC plays a more important role in the trimer structure of NF-YB-YC-CO in walnut species. Our study has further perfected the flowering regulatory network of walnut species.
磷脂酰乙醇胺结合蛋白（PEBP）具有保守的PEBP结构域，在调节被子植物的开花时间和生长方面发挥着重要作用。为了解胡桃科植物中PEBP家族基因的进化以及光周期途径中调控开花的机制，从5种胡桃科植物中鉴定出53个具有PEBP结构域的基因。胡桃科的PEBP基因家族可分为四个亚组，即FT-like、TFL-like、MFT-like和PEBP-like亚组。这些基因在胡桃科中对于基序和基因结构均显示出非常高的同源性。此外，基因复制和共线性分析结果表明，PEBP基因的进化主要是纯化选择，片段重复是胡桃科植物中PEBP基因家族进化的主要驱动力。我们发现PEBP基因家族在雌花芽分化中起重要作用，并且通过qRT-PCR分析发现大多数JrPEBP基因在叶芽和雌花芽中高表达。在拟南芥中，AtCO不仅可以直接与CORE2结合，还能与NF-Y复合物相互作用，正向调控AtFT基因的表达。在本研究中，我们证明JrCO（AtCO的直系同源物）不能直接调控JrFT基因的表达，但可以通过与NF-YB4/NF-YB6形成异源聚合物来增强JrNF-YB4/6蛋白与JrFT基因启动子的结合。我们还证实JrNF-YC1/3/7、JrNF-YB4/6和JrCO可以形成类似于拟南芥AtNF-YB-YC-CO的三聚体结构，然后结合到JrFT基因的启动子上以促进JrFT基因的转录。总之，通过对胡桃科植物PEBP基因家族的鉴定和分析以及对胡桃光周期途径调控开花机制的研究，我们发现核转录因子NF-YB/YC在胡桃属植物NF-YB-YC-CO三聚体结构中发挥着更重要的作用。我们的研究进一步完善了胡桃属植物的开花调控网络。
