NRPS-Derived Isoquinolines and Lipopetides Mediate Antagonism between Plant Pathogenic Fungi and Bacteria.
NRPS-Derived Isoquinolines and Lipopetides Mediate Antagonism between Plant Pathogenic Fungi and Bacteria.
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DOI：
10.1021/acschembio.7b00731
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发表时间：
2018-01-19
影响因子：
4
通讯作者：
Keller NP
中科院分区：
文献类型：
--
作者：
Khalid S;Baccile JA;Spraker JE;Tannous J;Imran M;Schroeder FC;Keller NP
细菌和真菌之间的相互作用被认为主要是由小分子信号介导的；然而，对调节病原体之间拮抗关系的信号网络知之甚少。在这里，我们证明了由植物病原细菌青枯雷尔氏菌产生的脂肽Ralstonins通过下调一个名为ImQ的隐蔽生物合成基因簇(BGC)的表达来干扰植物病原真菌黄曲霉的萌发。对转录因子ImqK高表达菌株的比较代谢组学分析表明，Imq依赖于一类三肽衍生生物碱的产生，即咪唑喹。这些生物碱是通过非核糖体肽合成酶(NRPS-)衍生的三肽产生的，并含有前所未有的三环咪唑[2，1-a]异喹啉环系。我们表明，咪唑喹对正常黄曲霉萌发所必需的氧化应激具有保护作用。添加纯化的咪喹酮可恢复ΔimqK A.黄曲霉菌株的野生型萌发，并保护该真菌免受ROS损害。细菌雷斯通抑制黄曲霉萌发，抑制ImQ簇的表达，而真菌咪喹素则抑制青枯病菌的生长。我们认为，这种相互的小分子介导的拮抗作用是影响相关物种致病性和存活率的微生物接触的共同特征。
Bacterial–fungal interactions are presumed to be mediated chiefly by small-molecule signals; however, little is known about the signaling networks that regulate antagonistic relationships between pathogens. Here, we show that the ralstonins, lipopeptides produced by the plant pathogenic bacteria Ralstonia solanacearum, interfere with germination of the plant-pathogenic fungus Aspergillus flavus by down-regulating expression of a cryptic biosynthetic gene cluster (BGC), named imq. Comparative metabolomic analysis of overexpression strains of the transcription factor ImqK revealed imq-dependent production of a family of tripeptide-derived alkaloids, the imizoquins. These alkaloids are produced via a nonribosomal peptide synthetase- (NRPS-)derived tripeptide and contain an unprecedented tricyclic imidazo[2,1-a]isoquinoline ring system. We show that the imizoquins serve a protective role against oxidative stress that is essential for normal A. flavus germination. Supplementation of purified imizoquins restored wildtype germination to a ΔimqK A. flavus strain and protected the fungus from ROS damage. Whereas the bacterial ralstonins retarded A. flavus germination and suppressed expression of the imq cluster, the fungal imizoquins in turn suppressed growth of R. solanacearum. We suggest such reciprocal small-molecule-mediated antagonism is a common feature in microbial encounters affecting pathogenicity and survival of the involved species.
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影响因子：
6
作者：
Baskaran, Rathinasamy;Poornima, Paramasivan;Padma, Viswanadha Vijaya
通讯作者：
Padma, Viswanadha Vijaya
影响因子：
3.3
作者：
Asai, Y;Nonaka, N;Komatsubara, S
通讯作者：
Komatsubara, S
影响因子：
4.4
作者：
Bok JW;Wiemann P;Garvey GS;Lim FY;Haas B;Wortman J;Keller NP
通讯作者：
Keller NP
影响因子：
4.2
作者：
Schrey SD;Erkenbrack E;Früh E;Fengler S;Hommel K;Horlacher N;Schulz D;Ecke M;Kulik A;Fiedler HP;Hampp R;Tarkka MT
通讯作者：
Tarkka MT
影响因子：
3
作者：
Porquier, Antoine;Morgant, Guillaume;Viaud, Muriel
通讯作者：
Viaud, Muriel