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OsBAK2/OsSERK2 expression is repressed by OsBZR1 to modulate brassinosteroid response and grain length in rice.
- Source :
-
Journal of Experimental Botany . 9/13/2023, Vol. 74 Issue 17, p4978-4993. 16p. - Publication Year :
- 2023
-
Abstract
- Brassinosteroids (BRs) are a class of polyhydroxylated steroidal phytohormones that are essential for plant growth and development. Rice BRASSINOSTEROID-INSENSITIVE1 (BRI1)-ASSOCIATED RECEPTOR KINASES (OsBAKs) are plasma membrane-localized receptor kinases belonging to the subfamily of leucine-rich repeat receptor kinases. It has been found that in Arabidopsis, BRs induce the formation of a BRI1–BAK1 heterodimer complex and transmit the cascade signal to BRASSINAZOLE RESISTANT1/ bri1 -EMS-SUPPRESSOR1 (BZR1/BES1) to regulate BR signaling. Here, in rice (Oryza sativa ssp. japonica), we found that OsBZR1 binds directly to the promoter of OsBAK2 , but not OsBAK1 , and represses the expression of OsBAK2 to form a BR feedback inhibition loop. Additionally, the phosphorylation of OsBZR1 by OsGSK3 reduced its binding to the OsBAK2 promoter. The osbak2 mutant displays a typical BR-deficiency phenotype and negative modulates the accumulation of OsBZR1. Interestingly, the grain length of the osbak2 mutant was increased whereas in the cr-osbak2 / cr-osbzr1 double mutant, the reduced grain length of the cr-osbzr1 mutant was restored, implying that the increased grain length of osbak2 may be due to the rice somatic embryogenesis receptor kinase-dependent pathway. Our study reveals a novel mechanism by which OsBAK2 and OsBZR1 engage in a negative feedback loop to maintain rice BR homeostasis, facilitating a deeper understanding of the BR signaling network and grain length regulation in rice. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00220957
- Volume :
- 74
- Issue :
- 17
- Database :
- Academic Search Index
- Journal :
- Journal of Experimental Botany
- Publication Type :
- Academic Journal
- Accession number :
- 171918931
- Full Text :
- https://doi.org/10.1093/jxb/erad196