Tyrosine phosphorylation constitutes up to 5% of the total phophoproteome. However, only limited studies are available on protein tyrosine kinases (PTKs) that catalyze protein tyrosine phosphorylation in plants. In this study, domain analysis of the 27 annotated PTK genes in rice genome led to the identification of 18 PTKs with tyrosine kinase domain. The kinase domain of rice PTKs shared high homology with that of dual specificity kinase BRASSINOSTEROID- INSENSITIVE 1 (BRI1) of Arabidopsis. In phylogenetic analysis, rice PTKs clustered with receptor-like cytoplasmic kinases-VII (RLCKs-VII) of Arabidopsis. mRNAseq analysis using Genevestigator revealed that rice PTKs except PTK9 and PTK16 express at moderate to high level in most tissues. PTK16 expression was highly abundant in panicle at flowering stage. mRNAseq data analysis led to the identification of drought, heat, salt, and submergence stress regulated PTK genes in rice. PTK14 was upregulated under all stresses. qRT-PCR analysis also showed that all PTKs except PTK10 were significantly upregulated in root under osmotic stress. Tissue specificity and abiotic stress mediated differential regulation of PTKs suggest their potential role in development and stress response of rice. The candidate dual specificity PTKs identified in this study paves way for molecular analysis of tyrosine phosphorylation in rice.

中文翻译：

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非典型蛋白酪氨酸激酶（PTK）基因的表征及其在水稻非生物胁迫响应中的作用。

酪氨酸磷酸化最多占总蛋白质组的5％。但是，关于蛋白质酪氨酸激酶（PTK）催化植物中蛋白质酪氨酸磷酸化的研究有限。在这项研究中，对水稻基因组中27个带注释的PTK基因的域分析导致鉴定出18个带有酪氨酸激酶域的PTK。水稻PTKs的激酶结构域与拟南芥的双特异性激酶BRASINOSTEROIDINSENSITIVE 1（BRI1）具有高度同源性。在系统发育 分析中，水稻PTKs与拟南芥的受体样细胞质激酶VII（RLCKs-VII）聚集在一起。使用Genevestigator mRNAseq分析表明，大米蛋白酪氨酸激酶除了PTK9和PTK16在大多数组织中以中度至高水平表达。在开花期，穗中PTK16的表达高度丰富。mRNAseq数据分析可鉴定水稻中受干旱，高温，盐和淹水胁迫调节的PTK基因。在所有压力下，PTK14均被上调。qRT-PCR分析还显示，除PTK10外，所有PTK在渗透胁迫下根部均显着上调。PTK的组织特异性和非生物胁迫介导的差异调节表明它们在水稻发育和胁迫响应中的潜在作用。候选双重特异性PTK 本研究中确定的方法为水稻中酪氨酸磷酸化的分子分析铺平了道路。