The BBX7/8-CCA1/LHY transcription factor cascade promotes shade avoidance by activating PIF4.

Autor: Bian Y; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China., Song Z; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China., Liu C; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China., Song Z; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China., Dong J; Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China., Xu D; State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2025 Jan; Vol. 245 (2), pp. 637-652. Date of Electronic Publication: 2024 Nov 08.
DOI: 10.1111/nph.20256
Abstrakt: Sun-loving plants undergo shade avoidance syndrome (SAS) to compete with their neighbors for sunlight in shade conditions. Phytochrome B (phyB) plays a dominant role in sensing the shading signals (low red to far-red ratios) and triggering SAS. Shade drives phyB conversion to inactive form, consequently leading to the accumulation of PHYTOCHROMEINTERACTING FACTOR 4 (PIF4) that promotes plant growth. Here, we show B-box PROTEIN 7 (BBX7)/BBX8 and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) positively regulate the low R : FR-induced PIF4 expression and promote the low R : FR-triggered hypocotyl growth in Arabidopsis. Shade interferes the interactions of phyB with BBX7 or BBX8 and triggers the accumulation of BBX7 and BBX8 independent of phyB. BBX7 and BBX8 associate with CCA1 and LHY to activate their transcription, the gene produces of which subsequently upregulate the expression of PIF4 in shade. Genetically, BBX7 and BBX8 act upstream of CCA1, LHY, and PIF4 with respect to hypocotyl growth in shade conditions. Our study reveals the BBX7/8-CCA1/LHY transcription factor cascade upregulates PIF4 expression and increases its abundance to promote plant growth and development in response to shade.
(© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)
Databáze: MEDLINE