Regulatory effects of nitric oxide on reproduction and melanin biosynthesis in onion pathogenic fungus Stemphylium eturmiunum

The formation of propagules is the critical stage for transmission pathogenic fungus Stemphylium eturmiunum. However, how development these regulated remains to be fully understood. Here, we show that nitric oxide (NO) necessary reproduction in S. eturmiunum.Application NO scavenger carboxy-CPTIO (cPTIO) or soluble guanylate cyclase (sGC) inhibitor NS-2028 abolishes formation, which was increased by a supplement sodium nitroprusside (SNP). SNP also triggered biosynthesis melanin, can inhibited upon addition arbutin tricyclazole, specific inhibitors DOPA and DHN synthetic pathway, respectively. Intriguingly, enhanced melanin corelates with an formation; SNP-induced increment compromised cPTIO NS-2028. RT-PCR analysis showed promoted transcription brlA, abA wetA at 0.2 mmol/L, but 2 mmol/L. In contrast, mat1, mat2, genes melanins down-regulated Thus, regulates synthesis eturmiunum possibly through NO-sGC-GMP signaling pathway.