番茄中一个新型胞质抗坏血酸过氧化物酶基因的分子克隆、表达及定位分析

Molecular cloning, expression and mapping analysis of a novel cytosolic ascorbate peroxidase gene from tomato.

作者信息

Zou Li-Ping, Li Han-Xia, Ouyang Bo, Zhang Jun-Hong, Ye Zhi-Biao

机构信息

National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.

出版信息

DNA Seq. 2005 Dec;16(6):456-61. doi: 10.1080/10425170500286858.

DOI:10.1080/10425170500286858

PMID:16287625

Abstract

Ascorbate peroxidase (APX, EC 1.11.1.11) plays a major role in H(2)O(2)-scavenging in plants and can help to avoid reactive oxygen species (ROS) damage. A new cytosolic APX gene was cloned from tomato (designated LecAPX2) by RACE-PCR. The full-length cDNA of LecAPX2 contained a complete open reading frame (ORF) of 753 bp, which encoding 250 amino acid residues. Homology analysis of LecAPX2 showed a 94% identity with potato cAPX gene and 92% identity with another tomato cAPX gene (APX20), the deduced amino acid showed 88% homology with APX20 protein and 75-92% identity with cAPX from other plants such as potato, tobacco, broccoli, spinach, pea, rice, etc. LecAPX2 revealed the existence of a haem peroxidase and plant APX family signatures. Northern blot analysis showed that LecAPX2 was constitutively expressed in root, stem, leaf, flower and fruit of tomato, whereas the expression levels were different. LecAPX2 was mapped to 6-A using 75 tomato introgression lines (ILs), each containing a single homozygous RFLP-defined chromosome segment from the green-fruited species Lycopersicon pennellii.

摘要

抗坏血酸过氧化物酶（APX，EC 1.11.1.11）在植物清除过氧化氢（H₂O₂）过程中起主要作用，有助于避免活性氧（ROS）损伤。通过RACE-PCR从番茄中克隆到一个新的胞质APX基因（命名为LecAPX2）。LecAPX2的全长cDNA包含一个753 bp的完整开放阅读框（ORF），编码250个氨基酸残基。LecAPX2的同源性分析表明，它与马铃薯cAPX基因的一致性为94%，与另一个番茄cAPX基因（APX20）的一致性为92%；推导的氨基酸序列与APX20蛋白的同源性为88%，与马铃薯、烟草、西兰花、菠菜、豌豆、水稻等其他植物的cAPX的一致性为75%-92%。LecAPX2具有血红素过氧化物酶和植物APX家族的特征。Northern杂交分析表明，LecAPX2在番茄的根、茎、叶、花和果实中组成型表达，但表达水平有所不同。利用75个番茄渐渗系（ILs）将LecAPX2定位到6-A染色体上，每个渐渗系都含有来自绿果番茄种潘那利番茄（Lycopersicon pennellii）的一个纯合RFLP定义的染色体片段。