[Effect of calcium on sporulation of Taiwanofungus camphoratus in submerged fermentation]

AbstractinEnglish, Chinese

Taiwanofungus camphoratus is a valuable and rare medicinal mushroom with various bioactivities, such as liver protection and anti-cancer. T. camphoratus can produce many arthroconidia at the end of submerged fermentation, but molecular mechanism underlying this submerged conidiation remains unknown. In this study, we found that Ca²⁺ concentration in culture medium significantly affected the arthroconidium production of T. camphoratus. Then, we identified two proteins (CaM and HSP90) involved in Ca²⁺/calmodulin signaling pathway and one protein (AbaA) involved in FluG-mediated conidiation pathway by two-dimensional electrophoresis analyses. Furthermore, we proposed a Ca²⁺/calmodulin- and FluG-mediated signaling pathway by bioinformatics analysis. By real-time quantitative PCR analyses of 23 key genes in the Ca²⁺/calmodulin- and FluG-mediated conidiation pathway, we found that expression levels of 7 genes (crz1, hsp90, flbB, brlA, abaA, wetA and fadA) showed significant responses to Ca²⁺ concentration in fermentation medium. Our research is beneficial for elucidating the underlying mechanism of submerged fermentation conidiation for T. camphoratus.

樟芝是原产于台湾的珍稀药用真菌，具有保肝、抗癌等活性。樟芝在深层发酵过程中能够产生大量无性孢子，但是目前对樟芝无性产孢的影响因素及其分子机制尚不明确。本研究报道了樟芝发酵培养基中Ca²⁺浓度能够有效调控樟芝无性产孢的现象；采用双向电泳 (2-DE) 技术，对不添加Ca²⁺培养 (对照) 的菌丝体、添加1 mmol/L Ca²⁺培养 (促进产孢) 的菌丝体及添加200 mmol/L Ca²⁺培养 (抑制产孢) 的菌丝体进行差异蛋白质组学分析，鉴定了参与Ca²⁺/钙调素信号通路的CaM 蛋白和HSP90 蛋白，以及参与FluG 调控产孢信号通路的AbaA 蛋白；进一步通过生物信息学分析，预测了Ca²⁺/钙调素和FluG 介导的樟芝无性产孢信号通路模型图；采用实时定量PCR (RT-qPCR) 技术，对该通路上23 个功能基因的转录水平进行了分析，发现了受Ca²⁺调控最为灵敏的7 个产孢相关功能基因：crz1、hsp90、flbB、brlA、abaA、wetA 及fadA。本研究结果为解析樟芝无性产孢机制提供了实验依据。.