Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain.
Unit of Environmental Biotechnology, Dresden University of Technology, International Institute Zittau, Zittau, Germany.
PLoS One. 2019 Mar 1;14(3):e0212769. doi: 10.1371/journal.pone.0212769. eCollection 2019.
The basidiomycete Chondrostereum purpureum (Silverleaf fungus) is a saprotroph and plant pathogen commercially used for combatting forest "weed" trees in vegetation management. However, little is known about its lignocellulose-degrading capabilities and the enzymatic machinery that is responsible for the degradative potential, and it is not yet clear to which group of wood-rot fungi it actually belongs. Here, we sequenced and analyzed the draft genome of C. purpureum (41.2 Mbp) and performed a quantitative proteomic approach during growth in submerged and solid-state cultures based on soybean meal suspension or containing beech wood supplemented with phenol-rich olive mill residues, respectively. The fungus harbors characteristic lignocellulolytic hydrolases (GH6 and GH7) and oxidoreductases (e.g. laccase, heme peroxidases). High abundance of some of these genes (e.g. 45 laccases, nine GH7) can be explained by gene expansion, e.g. identified for the laccase orthogroup ORTHOMCL11 that exhibits a total of 18 lineage-specific duplications. Other expanded genes families encode for proteins more related to a pathogenic lifestyle (e.g. protease and cytochrome P450s). The fungus responds to the presence of complex growth substrates (lignocellulose, phenolic residues) by the secretion of most of these lignocellulolytic and lignin-modifying enzymes (e.g. alcohol and aryl alcohol oxidases, laccases, GH6, GH7). Based on the genetic and enzymatic constitution, we consider the 'marasmioid' fungus C. purpureum as a 'phytopathogenic' white-rot fungus (WRF) that possesses a complex extracellular enzyme machinery to accomplish efficient lignocellulose degradation during both saprotrophic and phytopathogenic life phases.
担子菌胶膜菌（紫胶真菌）是一种腐生菌和植物病原体，在植被管理中被商业用于对抗森林“杂草”树木。然而，人们对其木质纤维素降解能力及其负责降解潜力的酶机制知之甚少，也不清楚它实际上属于哪一类木材腐朽真菌。在这里，我们对 C. purpureum（41.2 Mbp）进行了测序和分析，并在基于大豆粉悬浮液或分别含有富含酚类的橄榄厂废物的山毛榉木补充物的液体和固态培养中进行了定量蛋白质组学方法，研究了它的生长情况。该真菌具有特征性木质纤维素水解酶（GH6 和 GH7）和氧化还原酶（如漆酶、血红素过氧化物酶）。一些基因（如 45 个漆酶，9 个 GH7）的高丰度可以通过基因扩张来解释，例如在漆酶直系同源物 ORTHOMCL11 中识别到的，它总共具有 18 个谱系特异性的重复。其他扩展的基因家族编码与致病性生活方式更相关的蛋白质（如蛋白酶和细胞色素 P450s）。真菌通过分泌大多数木质纤维素和木质素修饰酶（如醇和芳醇氧化酶、漆酶、GH6、GH7）对复杂生长底物（木质纤维素、酚类残留物）的存在作出反应。基于遗传和酶组成，我们将“marasmioid”真菌 C. purpureum 视为具有复杂细胞外酶机制的“植物病原性”白腐真菌（WRF），该机制可在腐生和植物病原生活阶段有效地降解木质纤维素。
