%0 Journal Article
%T Characterization of cp3 reveals a new bri1 allele, bri1-120, and the importance of the LRR domain of BRI1 mediating BR signaling
%A Yun Shang
%A Myeong Lee
%A Jianming Li
%A Kyoung Nam
%J BMC Plant Biology
%D 2011
%I BioMed Central
%R 10.1186/1471-2229-11-8
%X Among the mutants showing altered growth patterns compared to wild type, we further characterized cp3, which displayed defective growth and reduced BR sensitivity. We sequenced the genomic DNA spanning BRI1 in the cp3 and found that cp3 has a point mutation in the region encoding the 13th LRR of BRI1, resulting in a change from serine to phenylalanine (S399F). We renamed it bri1-120. We also showed that overexpression of the wild type BRI1 protein rescued the phenotype of bri1-120. Using a GFP-tagged bri1-120 construct, we detected the bri1-120 protein in the plasma membrane, and showed that the phenotypic defects in the rosette leaves of bri1-301, a kinase-inactive weak allele of BRI1, can be restored by the overexpression of the bri1-120 proteins in bri1-301. We also produced bri1-301 mutants that were wild type in appearance by performing a genetic cross between bri1-301 and bri1-120 plants.We identified a new bri1 allele, bri1-120, whose mutation site has not yet been found or characterized. Our results indicated that the extracellular LRR regions before the 70-amino acid island domain of BRI1 are important for the appropriate cellular functioning of BRI1. Also, we confirmed that a successful interallelic complementation occurs between the extracellular domain mutant allele and the cytoplasmic kinase-inactive mutant allele of BRI1 in vivo.Numerous plant developmental processes, such as germination, cell elongation, photomorphogenic responses, and male fertility are regulated by the plant-specific steroidal hormones, brassinosteroids (BR). BR-biosynthetic or BR-perceiving mutants have exhibited defective growth patterns in various tissues that persist throughout their entire life span, indicating the critical role of BR in plant development [1,2]. Although studies researching the BR signaling process began much more recently than any of the other plant hormones, the identification of BRASSINOSTEROID-INSENSITIVE1 (BRI1), a receptor of BR [3], and several other imp
%U http://www.biomedcentral.com/1471-2229/11/8