Open AccessBBX32 Interacts with AGL24 Involved in Flowering Time Control in Chinese Cabbage (Brassica rapa L. ssp. pekinensis)
Author(s) -
Guan-Peng Ma,
Dan Zhao,
Tianwen Wang,
Lin-Bi Zhou,
Guilian Li
Publication year - 2018
Publication title -
notulae botanicae horti agrobotanici cluj-napoca
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.332
H-Index - 32
eISSN - 1842-4309
pISSN - 0255-965X
DOI - 10.15835/nbha47111205
Subject(s) - brassica rapa , biology , arabidopsis thaliana , zinc finger , transcription factor , arabidopsis , mads box , circadian clock , psychological repression , genetics , f box protein , two hybrid screening , brassica , microbiology and biotechnology , gene , mutant , botany , ubiquitin ligase , gene expression , ubiquitin
B-box (BBX) zinc finger proteins play critical roles in both vegetative and reproductive development in plants. Many BBX proteins have been identified in Arabidopsis thaliana as floral transition regulatory factors, such as CO, BBX7 (COL9), BBX19, and BBX32. BBX32 is involved in flowering time control through repression of COL3 in Arabidopsis thaliana, but it is still elusive that whether and how BBX32 directly interacts with flowering signal integrators of AGAMOUS-LIKE 24 (AGL24) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) in Chinese cabbage (Brassica rapa L. ssp. pekinensis) or other plants. In this study, B-box-32(BBX32), a transcription factor in this family with one B-box motif was cloned from B. rapa, acted as a circadian clock protein, showing expression changes during the circadian period. Additional experiments using GST pull-down and yeast two-hybrid assays indicated that BrBBX32 interacts with BrAGL24 and does not interact with BrSOC1, while BrAGL24 does interact with BrSOC1. To investigate the domains involved in these protein-protein interactions, we tested three regions of BrBBX32. Only the N-terminus interacted with BrAGL24, indicating that the B-box domain may be the key region for protein interaction. Based on these data, we propose that BrBBX32 may act in the circadian clock pathway and relate to the mechanism of flowering time regulation by binding to BrAGL24 through the B-box domain. This study will provide valuable information for unraveling the molecular regulatory mechanisms of BrBBX32 in flowering time of B. rapa.