Ballester Ana-Rosa, López-Pérez Mario, de la Fuente Beatriz, González-Candelas Luis
Department of Food Biotechnology, Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Calle Catedrático Agustín Escardino 7, 46980 Paterna, Valencia, Spain.
Microorganisms. 2019 Jul 12;7(7):198. doi: 10.3390/microorganisms7070198.
is the major postharvest pathogen of citrus fruit under Mediterranean climate conditions. Previous results have shown that proteases is the largest enzyme family induced by during fruit infection. In the present work, we addressed the study of the role of 's proteases in virulence following two complementary approaches. In the first approach, we undertook the functional characterization of the gene, which codes for a putative transcription factor previously shown to regulate extracellular proteases in other filamentous fungi. Deletion of caused a significant loss in secreted protease activity during growth assays. However, there was no effect on virulence. Gene expression of the two major secreted acid proteases was barely affected in the Δ deletant during infection of citrus fruit. Hence, no conclusion could be drawn on the role of these secreted acidic proteases on the virulence of . In the second approach, we studied the effect of different protease inhibitors and chelators on virulence. Co-inoculation of citrus fruit with conidia and a cocktail of protease inhibitors resulted in almost a complete absence of disease development. Analysis of individual inhibitors revealed that the metalloprotease inhibitor, 1,10-phenanthroline, was responsible for the observed effect. The application of metal ions reverted the protective effect caused by the metallopeptidase inhibitor. These results may set the basis for the development of new alternative treatments to combat this important postharvest pathogen.
在地中海气候条件下，是柑橘类水果采后的主要病原菌。先前的研究结果表明，蛋白酶是果实感染期间诱导产生的最大酶家族。在本研究中，我们采用两种互补的方法来研究该病原菌蛋白酶在致病力中的作用。在第一种方法中，我们对基因进行了功能表征，该基因编码一种推定的转录因子，先前已证明其可调节其他丝状真菌中的细胞外蛋白酶。在生长试验中，基因缺失导致分泌的蛋白酶活性显著丧失。然而，对致病力没有影响。在柑橘果实感染期间，两种主要分泌酸性蛋白酶的基因表达在缺失突变体中几乎未受影响。因此，无法得出这些分泌的酸性蛋白酶对该病原菌致病力作用的结论。在第二种方法中，我们研究了不同蛋白酶抑制剂和螯合剂对致病力的影响。将柑橘果实与分生孢子和蛋白酶抑制剂混合物共同接种，几乎完全没有病害发展。对单个抑制剂的分析表明，金属蛋白酶抑制剂1,10 - 菲咯啉是造成观察到的效果的原因。金属离子的应用逆转了金属肽酶抑制剂引起的保护作用。这些结果可能为开发对抗这种重要采后病原菌的新替代处理方法奠定基础。
