肺形侧耳线粒体基因组多态性鉴定

线粒体是能量转化与ATP形成的重要场所,已有多种食用真菌的线粒体基因组被相继组装注释,但肺形侧耳的线粒体基因组鲜有报道。本研究对野生肺形侧耳X2菌株的线粒体基因组进行组装并注释,由野生菌株X2与主栽菌株JX线粒体大片段差异序列,构建分子标记来鉴别野生和主栽肺形侧耳菌株。结果显示X2的线粒体基因组为大小75 709bp的闭合环状结构,含有rRNA的大小亚基基因,25个负责携带氨基酸的tRNA基因以及14个常见蛋白编码基因,在cox1基因上含有9个内含子。内含子主要为IB型,包含LAGLIDADG_1 superfamily、GIY-YIG_Cterm superfamily保守结构域。位于菌株X2与JX内含子和基因间区上的大片段差异序列,是造成种内线粒体多态性的主要因素。根据两菌株的差异片段构建系统进化树的结果显示,内含子、rnl-trnX、trnD-atp6序列能够将两株野生菌株和其他主栽菌株区分开,可用于野生肺形侧耳种内鉴定,而且trnD-atp6效果最佳。

Mitochondrial genome sequencing and polymorphism analysis of Pleurotus pulmonarius

Mitochondrium is an important organelle in eukaryotic cells for energy conversion and ATP formation. Many edible fungal mitochondrial genomes have been assembled and annotated, however, the mitogenome of Pleurotus pulmonarius is rarely reported. In this study, the mitogenome of the wild type P. pulmonarius strain X2 was assembled and annotated. Molecular markers were developed based on the mitogenomes of the strain X2 and commercial strain JX to classify a wide range of wild and commercial strains. The results showed that the mitogenome of P. pulmonarius is a closed ring structure with a size up to 75 709bp, containing small and large subunit genes of rRNA, 25 amino acids carrying tRNA genes and 14 common protein coding genes. The cox1 gene consists of nine introns mainly of IB type with conservative domain of LAGLIDADG_1 superfamily and GIY-YIG_C term superfamily. It was found that the differential fragment sequences are mainly located in the intron and intergenic regions, which are the main causes of mitochondrial polymorphism between strains X2 and JX. The phylogenetic tree was constructed with different fragment sequences, and the results indicated that the introns, rnl-trnX and trnD-atp6 sequences could be used to distinguish wild type strains from other commercial strains and could be used for the intraspecific identification of P. pulmonarius strains, however trnD-atp6 marker seemed more reliable in identification.