Tauber James P, Gallegos-Monterrosa Ramses, Kovács Ákos T, Shelest Ekaterina, Hoffmeister Dirk
Department of Pharmaceutical Microbiology at the Hans Knöll Institute, Friedrich-Schiller-University, Winzerlaer Str. 2, 07745 Jena, Germany.
Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University, Neugasse 23, 07743 Jena, Germany.
Microbiology (Reading). 2018 Jan;164(1):65-77. doi: 10.1099/mic.0.000582. Epub 2017 Dec 5.
Production of basidiomycete atromentin-derived pigments like variegatic acid (pulvinic acid-type) and involutin (diarylcyclopentenone) from the brown-rotter Serpula lacrymans and the ectomycorrhiza-forming Paxillus involutus, respectively, is induced by complex nutrition, and in the case of S. lacrymans, bacteria. Pigmentation in S. lacrymans was stimulated by 13 different bacteria and cell-wall-damaging enzymes (lytic enzymes and proteases), but not by lysozyme or mechanical damage. The use of protease inhibitors with Bacillus subtilis or heat-killed bacteria during co-culturing with S. lacrymans significantly reduced pigmentation indicating that enzymatic hyphal damage and/or released peptides, rather than mechanical injury, was the major cause of systemic pigment induction. Conversely, no significant pigmentation by bacteria was observed from P. involutus. We found additional putative transcriptional composite elements of atromentin synthetase genes in P. involutus and other ectomycorrhiza-forming species that were absent from S. lacrymans and other brown-rotters. Variegatic and its precursor xerocomic acid, but not involutin, in return inhibited swarming and colony biofilm spreading of Bacillus subtilis, but did not kill B. subtilis. We suggest that dissimilar pigment regulation by fungal lifestyle was a consequence of pigment bioactivity and additional promoter motifs. The focus on basidiomycete natural product gene induction and regulation will assist in future studies to determine global regulators, signalling pathways and associated transcription factors of basidiomycetes.
分别从褐腐菌泪菌（Serpula lacrymans）和形成外生菌根的卷缘桩菇（Paxillus involutus）中生产担子菌类源自黑团囊素的色素，如杂色酸（普尔文酸型）和内卷菌素（二芳基环戊烯酮），是由复杂营养诱导的，在泪菌的情况下，细菌也能诱导。泪菌中的色素沉着受到13种不同细菌和细胞壁损伤酶（裂解酶和蛋白酶）的刺激，但不受溶菌酶或机械损伤的刺激。在与泪菌共培养期间，使用蛋白酶抑制剂与枯草芽孢杆菌或热灭活细菌显著降低了色素沉着，这表明酶促菌丝损伤和/或释放的肽，而不是机械损伤，是系统性色素诱导的主要原因。相反，未观察到卷缘桩菇因细菌而产生显著色素沉着。我们在卷缘桩菇和其他形成外生菌根的物种中发现了黑团囊素合成酶基因的其他假定转录复合元件，而泪菌和其他褐腐菌中不存在这些元件。杂色酸及其前体干生酸，但不包括内卷菌素，反过来抑制了枯草芽孢杆菌的群体运动和菌落生物膜扩散，但没有杀死枯草芽孢杆菌。我们认为，真菌生活方式对色素的不同调节是色素生物活性和额外启动子基序的结果。对担子菌类天然产物基因诱导和调控的关注将有助于未来的研究，以确定担子菌类的全局调节因子、信号通路和相关转录因子。
