No abstract

The methyltransferase LaeA is a global regulator involved in the biosynthesis of secondary metabolites by ascomycete fungi. However, little is known of its regulatory role in basidiomycete fungi. In this study, the laeA gene was identified in the basidiomycete Ganoderma lingzhi and its function in regulating the biosynthesis of anti-tumor ganoderic acids was evaluated. A laeA deletion (ΔlaeA) Ganoderma strain exhibited significantly reduced concentration of ganoderic acids. qRT-PCR analysis further revealed that the transcription levels of genes involved in the biosynthesis of ganoderic acids were drastically lower in the ΔlaeA strain. Moreover, deletion of laeA resulted in decreased accumulation of intermediates and abundances of asexual spores in liquid static culture of G. lingzhi. In contrast, constitutive overexpression of laeA resulted in increased concentration of ganoderic acids. These results demonstrate an essential role of LaeA in the regulation of ganoderic acid biosynthesis in Ganoderma.

Coffee is one of the most popular beverages around the world. As one of the best-known coffee species, Liberian coffee ( Coffea liberica Bull ex Hiern 1876) has a high resistance to leaf rust, a devasting disease caused by Hemileia vastatrix . However, there are few reports on the systematic position and phylogenetic relationship of C. liberica at the chloroplast (cp) genome level. Thus, we successfully assembled its cp genome. The full length is 154,799 bp with a GC content of 37.48%. We have further annotated the cp genome and predicted 85 protein-coding genes together with 8 rRNAs and 37 tRNAs. Furthermore, a large single copy region (LSC), a small single copy region (SSC), an inverted repeat region a (IRa) and an inverted repeat region b (IRb) are identified with lengths of 84,868 bp, 18,121 bp, 25,905 bp and 25,905 bp, respectively. The phylogenetic tree indicates that C. liberica is closely related to C. canephora , which is consistent with a previous result obtained from genotyping‐by‐sequencing.