|XIA, RUI - South China Agricultural University|
Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/3/2020
Publication Date: 8/3/2020
Citation: Zhu, Y., Saltzgiver, M.J., Xia, R. 2020. Small RNA and degradome sequencing identified microRNA-target gene pairs regulating apple root defense responses towards Pythium ultimum infection [abstract]. APS Annual Meeting. Plant Health.
Technical Abstract: Small RNAs (sRNAs) play a key role in diverse plant biological processes including defense response to pathogens. The current study is part of a comprehensive transcriptomic analysis of molecular defense responses in apple root from infection by the soilborne necrotrophic oomycete pathogen Pythium ultimum. Thirty-six sRNA libraries, encompassing six apple rootstock genotypes with or without pathogen challenge, were constructed and sequenced. The deep sequencing and in-depth bioinformatic analysis of sRNA population uncovered novel characteristics of apple root defense response between resistant and susceptible genotypes. MicroRNA (miRNA)-target gene pair identification by degradome sequencing indicated that a broad range of cellular processes participate in defense responses including metabolite transportation and hormone synthesis. Notably, genotype-specific variations of miR393 family and miR393-triggered phasiRNAs (phased small interfering RNAs) through targeting auxin receptor TIR1, AFB2, and AFB3 appeared to be critical pathway regulating defense responses via hormone crosstalk. The miR482/2118 superfamily, which targets several NB-LRR genes, seemed to enhance effector-triggered immunity (ETI)-based resistance. The current study presents a complete population profile of miRNAs and their triggered phasiRNAs in apple roots under the pathogenic pressure from P. ultimum. The dataset provided valuable insight, in addition to previously comparative transcriptome analysis, to elucidate the molecular mechanisms regulating apple root resistance to P. ultimum.