Cloning and expression analysis of an hydrophobin gene Nrhyd in Nomuraea rileyi
莱氏野村菌疏水蛋白基因Nrhyd的克隆及其表达特征分析

The full-length cDNA of a hydrophobin gene Nrhyd gene was cloned from the insect pathogenic fungus Nomuraea rileyi using SMART RACE RT-PCR. The expression of Nrhyd gene by N. rileyi under different culture conditions was analyzed using Realtime-PCR, and the effects of different culture conditions on expression of Nrhyd gene on mRNA level were explored. Sequence analysis shows that the cDNA contains an open reading frame of 339bp which encoding a polypeptide with 111 amino acids. The precursor protein has a molecular mass of 10.6 and a calculated pI of 6.19. The RT-qPCR results showed that the expression of Nrhyd gene was suppressed under liquid culture condition. While under solid agar culture condition, the expression level of Nrhyd gene increased along with the formation of conidia and reached the highest level at day 8 of post-inoculation, and then decreased gradually. It is inferred therefore that the Nrhyd gene might play an important role in the formation of conidia in N. rileyi. Phylogenetics analysis of Nrhyd gene with other fungal hydrophobin indicates the gene is most closely related to the homologues from Metarhizium spp.