A DIVERGENT POLYGALACTURONASE OF FUSARIUM PHYLLOPHILUM SHOWS SEQUENCE AND FUNCTIONAL SIMILARITY TO THE ENZYME OF F. VERTICILLIOIDES
A DIVERGENT POLYGALACTURONASE OF FUSARIUM PHYLLOPHILUM SHOWS SEQUENCE AND FUNCTIONAL SIMILARITY TO THE ENZYME OF F. VERTICILLIOIDES
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Fusarium phyllophilum 的不同聚半乳糖醛酸酶与 Fusarium phylloides 的酶显示出序列和功能相似性
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
G. Lorenzo
中科院分区：
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作者：
L. Mariotti;M. Casasoli;C. Caprari;G. Lorenzo
内多聚半乳糖醛酸酶（endoPG）是真菌在感染过程中分泌的酶，用于降解植物细胞壁果胶。在镰刀菌属中，endoPG 是感染过程中首先产生的酶之一，在植物组织渗透和定殖中发挥着至关重要的作用。 F. phyllophilum 菌株FC-10（之前被分类为F. verticillioides）的endoPG 是特征最明确的镰刀菌细胞壁降解酶。在这项工作中，我们对endoPG（pg）基因序列进行了系统发育分析，证实了FC-10菌株为F. phyllophilum的分类，并且还显示了F. phyllophilum菌株NRRL 25305的pg基因的意外分歧。该基因和编码产物的生化特征似乎与F. verticillioides pg的相关性更为密切。这一观察结果和endoPGs经历正选择的证据表明，作用于这些酶的选择压力可能会限制它们的基因序列作为系统发育研究的可靠标记的使用。
Endopolygalacturonases (endoPGs) are fungal enzymes secreted during the infection in order to degrade plant cell wall pectins. In Fusarium spp., endoPGs are among the first enzymes produced during infection and play a crucial role in plant tissue penetration and colonization. The endoPG of F. phyllophilum strain FC-10, previously classified as F. verticillioides, is the best characterized Fusarium cell wall degrading enzyme. In this work we have carried out a phylogenetic analysis of the endoPG (pg) gene sequence that confirms the classification of the FC-10 strain as F. phyllophilum, and also shows an unexpected divergence of the pg gene of F. phyllophilum strain NRRL 25305. This gene and the biochemical characteristics of the encoded product appear more closely related to those of F. verticillioides pg. This observation and the evidence that endoPGs have experienced positive selection indicate that selective pressure acting on these enzymes may limit the use of their gene sequences as reliable markers for phylogenetic studies.