Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Characterization of cp3 reveals a new bri1 allele, bri1-120, and the importance of the LRR domain of BRI1 mediating BR signaling | Shang et al. BMC Plant Biology 2011 11 8 http 1471-2229 11 8 BMC Plant Biology RESEARCH ARTICLE Open Access Characterization of cp3 reveals a new bril allele bri1-120 and the importance of the LRR domain of BRI1 mediating BR signaling Yun Shang 1 Myeong Min Lee2 Jianming Li3 Kyoung Hee Nam1 Abstract Background Since the identification of BRI1 BRASSINOSTEROID-INSENSITIVE1 a brassinosteroids BRs receptor most of the critical roles of BR in plant development have been assessed using various bril mutant alleles. The characterization of individual bril mutants has shown that both the extracellular and cytoplasmic domains of BRI1 are important to its proper functioning. Particularly in the extracellular domain regions near the 70-amino acid island are known to be critical to BR binding. In comparison the exact function of the leucine rich-repeats LRR region located before the 70-amino acid island domain in the extracellular cellular portion of BRI1 has not yet been described due to a lack of specific mutant alleles. Results 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 BRIl 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 bril-120. We also showed that overexpression of the wild type BRI1 protein rescued the phenotype of bril-120. Using a GFP-tagged bril-120 construct we detected the bril-120 protein in the plasma membrane and showed that the phenotypic defects in the rosette leaves of bril-30l a kinase-inactive weak allele of BRIl can be restored by the overexpression of the bril-l20 proteins in bril-30l. We also produced bril-30l mutants that were wild type in appearance by performing a genetic cross between bril-30l and bril-l20 plants. Conclusions We identified a new bril allele
