Transcriptome analysis identifies candidate genes associated with melanin and toxin biosynthesis and pathogenicity of the maize pathogen, Curvularia lunata

Abstract

AbstractIn our previous study, we have successfully cloned and deleted the pks18 gene, which is involved in 1,8‐dihydroxynaphthalene melanin and methyl 5‐(hydroxymethyl) furan‐2‐carboxylate toxin production and in the pathogenicity of Curvularia lunata. Moreover, we hypothesized that other genes may also be related to the melanin and toxin production, or pathogenicity. In this study, a transcriptome approach based on the RNA‐Seq technique was used to identify specific genes associated with pks18 expression in pks18 deletion mutant ∆PKS18 and wild‐type CX‐3. A total of 137 overexpressed and 221 underexpressed genes were successfully identified in ∆PKS18. The NADPH–cytochrome P450 reductase gene CL00874, alcohol dehydrogenase gene CL02247 and L‐lactate dehydrogenase gene CL08767 may be required for the production of melanin and toxin. 1,4‐Beta‐D‐glucan cellobiohydrolase gene CL04068, ribonuclease III gene CL00399, salicylate hydroxylase gene CL00458 and tri14‐like protein gene CL00462 may contribute to the pathogenicity of C. lunata. Alternative splicing (AS) analysis revealed that over 76.15% of AS events involve the intron retention. This comprehensive transcriptomic analysis provides a key resource for understanding the molecular basis of melanin and toxin formation and for further elucidating the pathogenicity of C. lunata.