Pseudomonas syringae pv. tomato (Pst) is a pathogenic microorganism that causes bacterial speck disease and affects tomato yield and quality. Pto is a disease resistant gene for plant to recognize and defense against Pst. Pto interacts with Pti (Pto interacting) proteins, which include three transcription factors, Pti4, Pti5, Pti6, and they were thought to be downstream of Pto-mediated pathway to promote the expression of disease-related genes. In the present work, the overexpression plants of Pti4, Pti5 or Pti6 were obtained by Agrobacterium-mediated transformation in tomato. The Pti4/5/6-overexpressed lines indicated enhanced expression of pathogenesis-related genes and resistance to pathogenic bacteria Pst DC3000. Meanwhile, the transgenic plants showed that Pti4/5/6 function in ripening but performed no obvious adverse influence on flowering time, seed-setting rate, weight and soluble solids content of fruits. Furthermore, Pti-overexpressed fruits exhibited increased enzymatic activities of phenylalnine ammonialyase, catalase, peroxidase and decreased content of malondialdehyde. Additionally, cell-free and in vivo ubiquitination assay indicated that Pti4, Pti5 and Pti6 degraded by 26S proteasome which suggested that these Pti transcription regulators' functions could be regulated by ubiquitin-mediated post translational regulation in tomato.

中文翻译：

---

Pti4、Pti5和Pti6在番茄中的过表达促进植物防御和果实成熟

丁香假单胞菌光伏。番茄（Pst）是一种病原微生物，会引起细菌性斑点病，影响番茄产量和品质。Pto 是植物识别和防御 Pst 的抗病基因。Pto 与 Pti（Pto 相互作用）蛋白相互作用，其中包括 Pti4、Pti5、Pti6 三个转录因子，它们被认为是 Pto 介导通路的下游，促进疾病相关基因的表达。在目前的工作中，Pti4、Pti5 或 Pti6 的过表达植物是通过农杆菌介导的番茄转化获得的。Pti4/5/6 过表达的株系表明发病相关基因的表达增强和对病原菌 Pst DC3000 的抗性。同时，转基因植株表明Pti4/5/6具有催熟作用，但对果实的开花时间、结实率、重量和可溶性固形物含量无明显不利影响。此外，Pti 过表达的果实表现出苯丙氨酸解氨酶、过氧化氢酶、过氧化物酶的酶活性增加和丙二醛含量降低。此外，无细胞和体内泛素化试验表明 Pti4、Pti5 和 Pti6 被 26S 蛋白酶体降解，这表明这些 Pti 转录调节因子的功能可以通过泛素介导的番茄翻译后调节进行调节。过氧化物酶和丙二醛含量降低。此外，无细胞和体内泛素化试验表明 Pti4、Pti5 和 Pti6 被 26S 蛋白酶体降解，这表明这些 Pti 转录调节因子的功能可以通过泛素介导的番茄翻译后调节进行调节。过氧化物酶和丙二醛含量降低。此外，无细胞和体内泛素化试验表明 Pti4、Pti5 和 Pti6 被 26S 蛋白酶体降解，这表明这些 Pti 转录调节因子的功能可以通过泛素介导的番茄翻译后调节进行调节。