TY - JOUR
T1 - Overexpression of BBX18 Promotes Thermomorphogenesis Through the PRR5-PIF4 Pathway
AU - Hwang, Geonhee
AU - Park, Jeeyoon
AU - Kim, Soohwan
AU - Park, Jeonghyang
AU - Seo, Dain
AU - Oh, Eunkyoo
N1 - Funding Information:
This research was funded by the Basic Research Lab Program (2020R1A4A2002901) and the Basic Science Research Program (2019R1A2C1003783) of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, and a grant from Korea University.
Publisher Copyright:
Copyright © 2021 Hwang, Park, Kim, Park, Seo and Oh.
PY - 2021/11/24
Y1 - 2021/11/24
N2 - Thermomorphogenesis is the morphological response of plants to an elevation in the ambient temperature, which is mediated by the bHLH transcription factor PIF4. The evening-expressed clock component, PRR5, directly represses the expression of PIF4 mRNA. Additionally, PRR5 interacts with PIF4 protein and represses its transactivation activity, which in turn suppresses the thermoresponsive growth in the evening. Here, we found that the B-box zinc finger protein, BBX18, interacts with PRR5 through the B-Box2 domain. Deletion of the B-Box2 domain abolished the functions of BBX18, including the stimulation of PIF4 mRNA expression and hypocotyl growth. Overexpression of BBX18, and not of B-Box2-deleted BBX18, restored the expression of thermoresponsive genes in the evening. We further show that BBX18 prevents PRR5 from inhibiting PIF4-mediated high temperature responses. Taken together, our results suggest that BBX18 regulates thermoresponsive growth through the PRR5-PIF4 pathway.
AB - Thermomorphogenesis is the morphological response of plants to an elevation in the ambient temperature, which is mediated by the bHLH transcription factor PIF4. The evening-expressed clock component, PRR5, directly represses the expression of PIF4 mRNA. Additionally, PRR5 interacts with PIF4 protein and represses its transactivation activity, which in turn suppresses the thermoresponsive growth in the evening. Here, we found that the B-box zinc finger protein, BBX18, interacts with PRR5 through the B-Box2 domain. Deletion of the B-Box2 domain abolished the functions of BBX18, including the stimulation of PIF4 mRNA expression and hypocotyl growth. Overexpression of BBX18, and not of B-Box2-deleted BBX18, restored the expression of thermoresponsive genes in the evening. We further show that BBX18 prevents PRR5 from inhibiting PIF4-mediated high temperature responses. Taken together, our results suggest that BBX18 regulates thermoresponsive growth through the PRR5-PIF4 pathway.
KW - BBX18
KW - PIF4
KW - PRR5
KW - high temperature
KW - thermomorphogenesis
UR - http://www.scopus.com/inward/record.url?scp=85120878605&partnerID=8YFLogxK
U2 - 10.3389/fpls.2021.782352
DO - 10.3389/fpls.2021.782352
M3 - Article
AN - SCOPUS:85120878605
SN - 1664-462X
VL - 12
JO - Frontiers in Plant Science
JF - Frontiers in Plant Science
M1 - 782352
ER -