Abstract:
Arbuscular mycorrhizal fungi (AMF) enhance plant disease resistance, while the underlying mechanisms in the molecular levels are not yet known. In this study, five-leaf-old trifoliate orange seedlings were inoculated with Funneliformis mosseae for 14 weeks and subsequently were infected by a citrus root rot pathogen Phytophthora parasitica by 7 days. The transcriptome results by Illumina HiSeq 4000 revealed that the percentage of Q30 bases reached 92.99% or above, and 29696 unigenes were annotated in a total of 63531 unigenes. 654 and 103 differentially expressed genes (DEGs) were respectively annotated in AMF-inoculated versus non-AMF-inoculated plants under non-infection and infection with P. parasitica, respectively, whilst these DEGs were related to defense mechanisms, signal transduction mechanisms and secondary metabolites biosynthesis. Forty-two genes were functionally annotated as the putative 'defense mechanism', whilst AMF inoculation induced 1 gene down-regulated and 3 genes up-regulated under P. parasitica infection. AMF inoculation stimulated more genes linked to signal transduction mechanism down-regulated than non-AMF plants. Eight genes were involved in secondary metabolites biosynthesis in AMF versus non-AMF seedlings under P. parasitica-infection conditions. Such transcriptome database provided total information in the molecular levels regarding mycorrhizal roles in tolerating Phytophthora parasitica infection.
