Department of Genetics, Faculty of Biology, Complutense University of Madrid, 28040 Madrid, Spain.
J Sci Food Agric. 2013 Sep;93(12):3032-9. doi: 10.1002/jsfa.6136. Epub 2013 Apr 22.
Fusarium fujikuroi Nirenberg is a maize and rice pathogen causing important agricultural losses and produces fumonisins - mycotoxins which pose health risk to humans and farm animals. However, little information is available about the phylogenetics of this species and its ability to produce fumonisins in rice. We studied 32 strains isolated from rice in the Philippines and performed a phylogenetic analysis using the partial sequence of Elongation Factor 1 alpha (EF-1α) including isolates belonging to closely related species. Fumonisin B1 (FB1 ) production was analyzed in 7-day-old cultures grown in fumonisin-inducing medium by an enzyme-linked immunosorbent assay-based method and by real-time reverse transcriptase-polymerase chain reaction using primers for FUM1 gene, a key gene in fumonisin biosynthesis.
Nucleotide diversities per site (π) were 0.00024 ± 0.00022 (standard deviation) for the 32 F. fujikuroi strains from the Philippines and 0.00189 ± 0.00143 for all 34 F. fujikuroi strains, respectively. F. fujikuroi isolates grouped into one cluster separated from the rest of isolates belonging to the closely related F. proliferatum and showed very low variability, irrespective of their geographic origin. The cluster containing strains of F. proliferatum showed higher intraspecific variability than F. fujikuroi. Thirteen of the 32 strains analyzed were FB1 producers (40.62%), with production ranging from 0.386 to 223.83 ppm. All isolates analyzed showed FUM1 gene expression above 1 and higher than the CT value of the non-template control sample. Both seedling stunting and elongation were induced by the isolates in comparison with the control.
F. fujikuroi are distinct from F. proliferatum isolates based on phytogenetic analysis and are potential fumonisin producers because all are positive for FUM1 gene expression. No relationship between fumonisin production and pathogenicity could be observed.
藤仓镰刀菌 Nirenberg 是一种玉米和水稻病原体，可导致严重的农业损失，并产生伏马菌素——一种对人类和农场动物健康构成风险的真菌毒素。然而，关于该物种的系统发育及其在水稻中产生伏马菌素的能力的信息很少。我们研究了来自菲律宾水稻的 32 株分离株，并使用包括亲缘关系密切的种属在内的延伸因子 1α（EF-1α）的部分序列进行了系统发育分析。在伏马菌素诱导培养基中，通过酶联免疫吸附测定法和针对伏马菌素生物合成关键基因 FUM1 基因的实时逆转录聚合酶链反应，分析了 7 日龄培养物中的伏马菌素 B1（FB1）的产量。
来自菲律宾的 32 株藤仓镰刀菌的每个位点的核苷酸多样性（π）分别为 0.00024±0.00022（标准差），而所有 34 株藤仓镰刀菌的π分别为 0.00189±0.00143。藤仓镰刀菌分离株聚成一个与亲缘关系密切的层出镰刀菌的其余分离株分离的簇，并且无论其地理来源如何，都显示出非常低的变异性。包含层出镰刀菌的菌株的簇显示出比藤仓镰刀菌更高的种内变异性。在所分析的 32 株菌株中，有 13 株（40.62%）为 FB1 产生菌，其产量范围为 0.386 至 223.83ppm。所有分析的分离株的 FUM1 基因表达均高于 1 且高于非模板对照样品的 CT 值。与对照相比，分离物均能诱导幼苗矮化和伸长。
基于植物系统发育分析，藤仓镰刀菌与层出镰刀菌分离株不同，并且由于所有菌株的 FUM1 基因表达均为阳性，因此都是潜在的伏马菌素产生菌。未观察到伏马菌素产生与致病性之间的关系。
