ABSTRACT

The domain of unknown function (DUF221 domain-containing) proteins regulates various aspects of plant growth, development, responses to abiotic stresses, and hormone transduction pathways. To understand the role of DDP proteins in tomato, a comprehensive genome-wide analysis was performed in the tomato genome. A total of 12 DDP genes were identified and distributed in 8 chromosomes in the tomato genome. Phylogenetically all SlDDPs were clustered into four clades, subsequently supported by their gene structure and conserved motifs distribution. The SlDDPs contained various cis-acting elements involved in plant responses to abiotic and various phytohormones stresses. The tissue-specific expression profile analysis revealed the constitutive expression of SlDDPs in roots, leaves, and developmental phases of fruit. It was found that SlDDP1, SlDDP3, SlDDP4, SlDDP9, SlDDP10, and SlDDP12 exhibited high expression levels in fruits at different development stages. Of these genes, SlDDP12 contained ethylene (ERE) responsive elements in their promoter regions, suggesting its role in ethylene-dependent fruit ripening. It was found that a single SlDDP induced by two or more abiotic and phytohormone stresses. These include, SlDDP1, SlDDP2, SlDDP3, SlDDP4, SlDDP7, SlDDP8, and SlDDP10 was induced under salt, drought, ABA, and IAA stresses. Moreover, tomato SlDDPs were targeted by multiple miRNA gene families as well. In conclusion, this study predicted that the putative DDP genes might help improve abiotic and phytohormone tolerance in plants, particularly tomato, rice, and other economically important crop plant species.

摘要

未知功能域（含 DUF221 域）蛋白调节植物生长、发育、对非生物胁迫的反应和激素转导途径的各个方面。为了了解 DDP 蛋白在番茄中的作用，对番茄基因组进行了全面的全基因组分析。共鉴定出12个DDP基因，分布在番茄基因组的8条染色体上。在系统发育上，所有 SlDDP 都聚集成四个进化枝，随后受到它们的基因结构和保守基序分布的支持。SlDDPs 包含涉及植物对非生物和各种植物激素胁迫的反应的各种顺式作用元件。组织特异性表达谱分析揭示了SlDDPs的组成型表达在果实的根、叶和发育阶段。发现SlDDP1、SlDDP3、SlDDP4、SlDDP9、SlDDP10和SlDDP12在不同发育阶段的果实中均表现出高表达水平。在这些基因中，SlDDP12在其启动子区域含有乙烯 (ERE) 响应元件，表明其在乙烯依赖性果实成熟中的作用。发现由两种或多种非生物和植物激素胁迫诱导的单个SlDDP。这些包括，SlDDP1、SlDDP2、SlDDP3、SlDDP4、SlDDP7、SlDDP8和SlDDP10在盐、干旱、ABA和IAA胁迫下诱导。此外，番茄 SlDDPs 也被多个 miRNA 基因家族靶向。总之，这项研究预测，假定的 DDP 基因可能有助于提高植物的非生物和植物激素耐受性，特别是番茄、水稻和其他经济上重要的作物植物物种。