Transcriptome Analysis of Korla Fragrant Pear Reveals a Comprehensive Signaling Network in Response to Alternaria alternata Infection

Abstract

Blackhead caused by Alternaria alternata is a fatal necrotrophic fungal that affects Korla fragrant pear. To date, little is known at the molecular level about the defense response of pear to blackhead disease and the pathogenic mechanism of A. alternata infection. To investigate the specific host-pathogen interaction between A. alternata and pear, we examined the accumulation of host-responsive mRNAs using RNA-seq technology. A total of 25,877 differentially expressed genes (DEGs) were identified. Further analysis revealed that the DEGs mainly participate in plant cell wall integrity, plant hormone pathways, plant-pathogen interactions and the defense response (transcription factors, defense-related proteins). Most of the DEGs involved in the plant hormone, PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI) pathways, as well as defense-related proteins, were significantly up-regulated. In addition, DEGs encoding enzymes involved in cutin and wax synthesis and most transcription factors are significantly down-regulated. Based on these results, we speculate that these pathways play important roles in the response of pear to A. alternata. This study has presented new insights into the molecular mechanisms that regulate the response of pear fruits to A. alternata infection. © 2021 Friends Science Publishers