Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.
Department of Biology, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.
Int J Mol Sci. 2019 Mar 6;20(5):1138. doi: 10.3390/ijms20051138.
Brassinosteroids (BRs) are steroid hormones essential for different biological processes, ranging from growth to environmental adaptation in plants. The plant brassinosteroid-signaling kinase (BSK) proteins belong to a family of receptor-like cytoplasmic kinases, which have been reported to play an important role in BR signal transduction. However, the knowledge of BSK genes in plants is still quite limited. In the present study, a total of 143 BSK proteins were identified by a genome-wide search in 17 plant species. A phylogenetic analysis showed that the BSK gene originated in embryophytes, with no BSK found in green algae, and these BSK genes were divided into six groups by comparison with orthologs/paralogs. A further study using comparative analyses of gene structure, expression patterns and alternative splicing of BSK genes in revealed that all BSK proteins shared similar protein structure with some exception and post-translation modifications including sumolyation and ubiquitination. An expression profile analysis showed that most BSK genes were constitutively expressed in different tissues; of these, several BSK genes were significantly expressed in response to some hormones or abiotic stresses. Furthermore, reverse transcription-polymerase chain reaction (RT-PCR) assays showed that , , and underwent alternative splicing in specific stress induced and tissue-dependent patterns. Collectively, these results lay the foundation for further functional analyses of these genes in plants.
油菜素甾醇（BRs）是植物生长和环境适应等不同生物学过程所必需的甾体激素。植物油菜素甾醇信号激酶（BSK）蛋白属于受体样细胞质激酶家族，据报道，它们在 BR 信号转导中发挥着重要作用。然而，关于植物 BSK 基因的知识仍然相当有限。在本研究中，通过对 17 种植物物种的全基因组搜索，共鉴定出 143 种 BSK 蛋白。系统发育分析表明，BSK 基因起源于胚胎植物，绿藻中没有 BSK，这些 BSK 基因通过与同源物/旁系同源物的比较分为六个组。进一步通过比较分析揭示了 BSK 基因在中的基因结构、表达模式和选择性剪接，表明所有 BSK 蛋白都具有相似的蛋白质结构，但也存在一些例外和翻译后修饰，包括 SUMO 化和泛素化。表达谱分析表明，大多数 BSK 基因在不同组织中持续表达；其中，一些 BSK 基因在对某些激素或非生物胁迫的响应中表达显著。此外，反转录-聚合酶链反应（RT-PCR）检测显示，在特定的胁迫诱导和组织依赖性模式下， 、 和 发生了选择性剪接。总之，这些结果为进一步研究这些基因在植物中的功能奠定了基础。
