Characterization of Maize miRNAs in Response to Synergistic Infection of Maize Chlorotic Mottle Virus and Sugarcane Mosaic Virus

Abstract

The synergistic infection of maize chlorotic mottle virus (MCMV) and sugarcane mosaic virus (SCMV) causes maize lethal necrosis, with considerable losses to global maize production. microRNAs (miRNAs) are conserved non-coding small RNAs that play essential regulatory roles in plant development and environmental stress responses, including virus infection. However, the characterization of maize miRNAs in response to synergistic infection of MCMV and SCMV remains largely unknown. In this study, the profiles of small RNAs from MCMV and SCMV single- and co-infected (S + M) maize plants were obtained by high-throughput sequencing. A total of 173 known miRNAs, belonging to 26 miRNA families, and 49 novel miRNAs were profiled. The expression patterns of most miRNAs in S + M-infected maize plants were similar to that in SCMV-infected maize plants, probably due to the existence of RNA silencing suppressor HC-Pro. Northern blotting and quantitative real-time PCR were performed to validate the accumulation of miRNAs and their targets in different experimental treatments, respectively. The down-regulation of miR159, miR393, and miR394 might be involved in antiviral defense to synergistic infection. These results provide novel insights into the regulatory networks of miRNAs in maize plants in response to the synergistic infection of MCMV and SCMV.

Comprehensive Transcriptome Analyses Reveal Candidate Genes for Variation in Seed Size/Weight During Peanut (Arachis hypogaea L.) Domestication

“…Due to decreased cost and high efficiency, RNA-seq based on next-generation sequencing (NGS) technology has revolutionized genomic investigations in many plant species, and is essential for molecular marker development ( Trick et al, 2012 ; Wang et al, 2017 ), mapping and identification of candidate genes for traits of interest ( Liu S. et al, 2012 ; Islam et al, 2016 ; Li et al, 2019 ), characterization of non-coding small RNA molecules ( Lu et al, 2015 ; Xia et al, 2019 ; Han et al, 2020 ), and detecting variations in gene structure. More importantly, in the past decade, RNA-seq has become an essential tool for the analysis of DEGs at the global transcriptome level and for the development of special gene expression atlases in various crop species ( Dukowic-Schulze et al, 2014 ; Garg et al, 2017 ; Gao et al, 2018 ) including peanut ( Chen X. et al, 2016 ; Clevenger et al, 2016 ; Sinha et al, 2020 ).…”

The miR393-Target Module Regulates Plant Development and Responses to Biotic and Abiotic Stresses

“…In rice, the overexpression of miR393 decreased the TIR1 expression and increased plant susceptibility to Rice Black Streaked Dwarf Virus (RBSDV) [ 39 ]. sRNA-seq analysis revealed that the down-regulation of miR393 in maize might be related to the plant antiviral defense to synergistic infection [ 89 ]. The miR393 expression was significantly decreased in a sensitive cultivar (Hanatee) of cassava infected by Colletotrichum gloeosporioides but increased in resistant cultivar Huay Bong 60 [ 90 ].…”

Maize Lethal Necrosis disease: review of molecular and genetic resistance mechanisms, socio-economic impacts, and mitigation strategies in sub-Saharan Africa

“…Analysis of miRNA profiles, therefore, can help to decipher the response of the host plants to viral infection. An expression profile of maize miRNAs, obtained by challenging maize inbred line B73 with MCMV and SCMV individually and in combination revealed that expression patterns of most miRNAs were similar for single infection of SCMV and double infection with SCMV and MCMV except three miRNAs (miR159, miR393, and miR394) that were downregulated by the synergistic infection of both viruses [ 108 ]. In silico analysis indicates that these miRNAs could be playing a role in the MCMV and SCMV interaction [ 39 ].…”

“…Similarly, miR394 was also upregulated in drought tolerant mung bean leaves [ 121 ]. However, miR159 and miR394 were down-regulated in either MCMV only or SCMV and MCMV coinfected maize leaves [ 108 ]. This indicates that the MLN infected maize lines may show lower drought tolerance, which is important for the sub-Saharan Africa.…”