Fumonisin and Beauvericin Chemotypes and Genotypes of the Sister Species Fusarium subglutinans and Fusarium temperatum
Fumonisin and Beauvericin Chemotypes and Genotypes of the Sister Species Fusarium subglutinans and Fusarium temperatum
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DOI：
10.1128/aem.00133-20
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发表时间：
2020-07-01
影响因子：
4.4
通讯作者：
Moretti, Antonio
中科院分区：
文献类型：
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作者：
Fumero, M. Veronica;Villani, Alessandra;Moretti, Antonio
玉米镰刀菌（Fusarium subarumans）和温度镰刀菌（Fusarium temperatum）是玉米上常见的病原菌，它们产生真菌毒素并引起植物病害。这些物种产生白僵菌素和伏马菌素真菌毒素的能力尚未确定，因为关于毒素产生的报道并不一致。我们的目的是通过确定两个物种菌株的化学型和基因型来澄清这种情况。我们分析了来自阿根廷的25个菌株，13个F. submerganans和12个F. temperatum菌株，用于通过超高效液相色谱质谱法（UPLC-MS）的毒素生产。我们使用了来自两株F. subacrylans和一株F. temperatum，加上其他镰刀菌物种的基因组，以确定这些毒素的合成功能基因簇的存在。从这两个物种中检测的菌株均不产生伏马菌素。这些菌株也缺乏Fum生物合成基因，但保留了轮枝镰刀菌中Fum簇侧翼的一些基因的同源物。没有一个F。虽然12株F. temperatum strains.一个完整的白僵菌素（Bea）基因簇存在于所有三个新的基因组序列。推测比尔基因在F. temperatum的功能，但在F.由于大的插入和多个突变导致过早的终止密码子，因此可以将其与subacrylans结合。只有少数突变的积累预期破坏比尔表明，其失活的过程是相对较新的。因此，F. subacrylans或F. temperatum产生伏马菌素，F.被检查的枯草芽孢杆菌也不能产生白僵菌素。不同菌株对F.温带镰刀菌产生白僵菌素需要进一步的研究，并可能反映最近这两个物种的共同祖先。温带真菌是姐妹种和玉米病原体，通常在世界范围内分离，可产生几种真菌毒素并引起幼苗病害、茎腐病和穗腐病。这些物种产生白僵菌素和伏马菌素真菌毒素的能力尚未确定，因为关于毒素产生的报告在物种水平上并不一致。我们的结果与以前报道的F.枯草芽孢杆菌既不产生伏马菌素也不产生白僵菌素。本文对F. temperatum需要进一步的工作。我们的菌株F.温带不产生伏马菌素，而一些菌株产生白僵菌素，而另一些则不产生。如果存在这些物种的菌株，这些结果可以更准确地评估潜在真菌毒素污染的风险。BEA 1基因失活的性质与其相对较新的发生和两个姐妹物种的密切系统发育关系一致。
Fusarium subglutinans and Fusarium temperatum are common maize pathogens that produce mycotoxins and cause plant disease. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant. Our objective was to clarify this situation by determining both the chemotypes and genotypes for strains from both species. We analyzed 25 strains from Argentina, 13 F. subglutinans and 12 F. temperatum strains, for toxin production by ultraperformance liquid chromatography mass spectrometry (UPLC-MS). We used new genome sequences from two strains of F. subglutinans and one strain of F. temperatum, plus genomes of other Fusarium species, to determine the presence of functional gene clusters for the synthesis of these toxins. None of the strains examined from either species produced fumonisins. These strains also lack Fum biosynthetic genes but retain homologs of some genes that flank the Fum cluster in Fusarium verticillioides. None of the F. subglutinans strains we examined produced beauvericin although 9 of 12 F. temperatum strains did. A complete beauvericin (Bea) gene cluster was present in all three new genome sequences. The Beal gene was presumably functional in F. temperatum but was not functional in F. subglutinans due to a large insertion and multiple mutations that resulted in premature stop codons. The accumulation of only a few mutations expected to disrupt Beal suggests that the process of its inactivation is relatively recent. Thus, none of the strains of F. subglutinans or F. temperatum we examined produce fumonisins, and the strains of F. subglutinans examined also cannot produce beauvericin. Variation in the ability of strains of F. temperatum to produce beauvericin requires further study and could reflect the recent shared ancestry of these two species.IMPORTANCE Fusarium subglutinans and F. temperatum are sister species and maize pathogens commonly isolated worldwide that can produce several mycotoxins and cause seedling disease, stalk rot, and ear rot. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant at the species level. Our results are consistent with previous reports that strains of F. subglutinans produce neither fumonisins nor beauvericin. The status of toxin production by F. temperatum needs further work. Our strains of F. temperatum did not produce fumonisins, while some strains produced beauvericin and others did not. These results enable more accurate risk assessments of potential mycotoxin contamination if strains of these species are present. The nature of the genetic inactivation of BEA1 is consistent with its relatively recent occurrence and the close phylogenetic relationship of the two sister species.