Functional divergence of BAK1 genes from Brassica rapa in regulating plant architecture

Abstract

ABSTRACT. BAK1 is a co-receptor of BRI1 in early signaling pathways mediated by brassinosteroids (BRs) and is thought to play a major role in plant growth and development. As the role of BAK1 has not yet been fully elucidated then further research is required to explore its potential for use in genetic modification to improve crops. In this study, three BAK1 genes from the amphidiploid species Brassica rapa were isolated and their kinase functions were predicted following DNA sequence analysis. A bioinformatic analysis revealed that two genes, BrBAK1-1 and BrBAK1-8, shared a conserved kinase domain and 5 tandem leucine-rich repeats (LRRs) that are characteristic of a BAK1 receptor for BR perception, whereas the third gene, BrBAK1-3, was deficient for a signal peptide, but had 4 leucine zippers and 3 leucine-rich repeats (LRRs) in an extracellular domain. All three BrBAK1 kinases localized on the cellular membrane. Ectopic expression of each BrBAK1 gene in BR-insensitive (bri1-5 mutant) Arabidopsis plants indicated that BrBAK1-1 and BrBAK1-8 were functional homologues of AtBAK1 based on the rescue of growth in the bri1-5 mutant. Overexpression of BrBAK1-3 caused a severe dwarf phenotype resembling the phenotype of null BRI1 alleles. The results here suggest there are significant differences among the three BrBAK1 kinases for their effects on plant architecture. This conclusion has important implications for genetic modification of B. rapa.

The impact of pRAP vectors on plant genetic transformation and pathogenesis studies including an analysis of BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1)-mediated resistance

“…This process has been shown to be an essential prerequisite for BIK1 release from the FLS2-BAK1 complex leading to immune signaling activation (Ma et al 2020). The conserved nature of PTI and ETI indicate that homologs of these genes exist in the other important agricultural plant species described earlier including cassava, maize, rice, wheat, sorghum, rape seed, potato, tomato, oil palm, sugarcane and sugar beet and in some cases have been described (Gao et al 2013;Bajwa et al 2013;Zhang et al 2015;Khew et al 2015;Wang et al 2018b;Yu et al 2020).…”

BAK1 Mediates Light Intensity to Phosphorylate and Activate Catalases to Regulate Plant Growth and Development

“…Subcellular localization assays were performed as described previously [51]. For the generation of GFP-fusion protein, the coding sequence of each CAT was constructed into a vector Cam-35S-GFP vector.…”

Genome-wide identification of SERK genes in apple and analyses of their role in stress responses and growth

“…The first SERK gene was identified in Daucus carota , and was shown to play an important role in the formation from of embryos from single somatic cells [5]. SERK genes have recently been identified in Arabidopsis thaliana , tomato, rice and Brassica rapa [6–9].…”