The plant pathogen Pantoea ananatis produces N-acylhomoserine lactone and causes center rot disease of onion by quorum sensing
The plant pathogen Pantoea ananatis produces N-acylhomoserine lactone and causes center rot disease of onion by quorum sensing
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DOI：
10.1128/jb.01054-07
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发表时间：
2007-11-01
影响因子：
3.2
通讯作者：
Ikeda, Tsukasa
中科院分区：
文献类型：
--
作者：
Morohoshi, Tomohiro;Nakamura, Yuta;Ikeda, Tsukasa
许多革兰氏阴性菌具有群体感应系统，并产生N-酰基-L-高丝氨酸内酯（阿勒），它们将其用作群体感应信号分子。菠萝泛菌（Pantoea ananatis）是小麦成熟期的一种常见寄生菌，可引起洋葱的中心腐烂。在本研究中，我们证明了菠萝斑潜蝇SK-1产生两种AHL，N-己酰基-L-高丝氨酸内酯（C6-HSL）和N-（3-氧代己酰基）-L-高丝氨酸内酯（3-氧代-C6-HSL）。我们克隆了AHL合成酶基因（eanI）和AHL受体基因（eanR），发现EanI/EanR的氨基酸序列与斯氏毕赤酵母EsaI/EsaR的氨基酸序列高度同源。EanR抑制了ean box序列，AHLs的加入导致了ean box的去抑制。SK-1中染色体eanI基因的失活导致胞外多糖（EPS）生物合成、生物膜形成和洋葱叶片感染的中断，这些通过添加外源3-oxo-C6-HSL来恢复。这些结果表明，群体感应系统参与了菠萝斑潜蝇SK-1的EPS生物合成、生物膜形成和洋葱叶片的感染。
A number of gram-negative bacteria have a quorum-sensing system and produce N-acyl-L-homoserine lactone (AHL) that they use them as a quorum-sensing signal molecule. Pantoea ananatis is reported as a common colonist of wheat heads at ripening and causes center rot of onion. In this study, we demonstrated that P. ananatis SK-1 produced two AHLs, N-hexanoyl-L-homoserine lactone (C6-HSL) and N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL). We cloned the AHL-synthase gene (eanI) and AHL-receptor gene (eanR) and revealed that the deduced amino acid sequence of EanI/EanR showed high identity to those of EsaI/EsaR from P. stewartii. EanR repressed the ean box sequence and the addition of AHLs resulted in derepression of ean box. Inactivation of the chromosomal eanI gene in SK-1 caused disruption of exopolysaccharide (EPS) biosynthesis, biofilm formation, and infection of onion leaves, which were recovered by adding exogenous 3-oxo-C6-HSL. These results demonstrated that the quorum-sensing system involved the biosynthesis of EPS, biofilm formation, and infection of onion leaves in P. ananatis SK-1.