Identification of a 12-Gene Fusaric Acid Biosynthetic Gene Cluster in Fusarium Species Through Comparative and Functional Genomics
Identification of a 12-Gene Fusaric Acid Biosynthetic Gene Cluster in Fusarium Species Through Comparative and Functional Genomics
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DOI：
10.1094/mpmi-09-14-0264-r
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发表时间：
2015-03-01
影响因子：
3.5
通讯作者：
Lee, Theresa
中科院分区：
文献类型：
--
作者：
Brown, Daren W.;Lee, Seung-Ho;Lee, Theresa
在真菌中，参与次生代谢物（SM）生物合成的基因通常在基因组中彼此相邻，并受到协调调控。这些SM生物合成基因簇通常编码酶、一种或多种转录因子和转运蛋白。镰刀菌酸是由镰刀菌属真菌的多个物种产生的聚酮衍生的SM。这种SM是令人关注的，因为它对动物有毒，因此被认为是一种真菌毒素，可能有助于植物致病。镰刀菌酸（FA）生物合成基因（FUB）簇的初步描述已在两个镰刀菌物种，玉米病原体轮枝镰刀菌和水稻病原体藤仓镰刀菌。该簇由五个基因组成，不包括转录因子或转运蛋白基因。在这里，分析的FUB区域在E轮枝孢，E藤仓，和E尖孢，一种植物病原体与多个主机，表明FUB集群由至少12个基因（FUB 1到FUB 12）。缺失分析证实，9个FUB基因，包括两个Zn（II）（2）Cys（6）转录因子基因，需要生产野生型水平的FA。多个镰刀菌属分离株和物种的FUB簇同源物的比较显示，在一些同源物中的一个或两个位置插入非FUB基因。虽然FA的产生能力有助于尖孢E培养提取物的植物毒性，缺乏生产并不影响尖孢E对仙人掌或E verticillioides对玉米幼苗的毒性。这些发现为FA生产所需的遗传和生化过程提供了新的见解。
In fungi, genes involved in biosynthesis of a secondary metabolite (SM) are often located adjacent to one another in the genome and are coordinately regulated. These SM biosynthetic gene clusters typically encode enzymes, one or more transcription factors, and a transport protein. Fusaric acid is a polyketide-derived SM produced by multiple species of the fungal genus Fusarium. This SM is of concern because it is toxic to animals and, therefore, is considered a mycotoxin and may contribute to plant pathogenesis. Preliminary descriptions of the fusaric acid (FA) biosynthetic gene (FUB) cluster have been reported in two Fusarium species, the maize pathogen E verticillioides and the rice pathogen E fujikuroi. The cluster consisted of five genes and did not include a transcription factor or transporter gene. Here, analysis of the FUB region in E verticillioides, E fujikuroi, and E oxysporum, a plant pathogen with multiple hosts, indicates the FUB cluster consists of at least 12 genes (FUB1 to FUB12). Deletion analysis confirmed that nine FUB genes, including two Zn(II)(2)Cys(6) transcription factor genes, are required for production of wild-type levels of FA. Comparisons of FUB cluster homologs across multiple Fusarium isolates and species revealed insertion of non-FUB genes at one or two locations in some homologs. Although the ability to produce FA contributed to the phytotoxicity of E oxysporum culture extracts, lack of production did not affect virulence of E oxysporum on cactus or E verticillioides on maize seedlings. These findings provide new insights into the genetic and biochemical processes required for FA production.