Suppression of nbe-miR1919c-5p Expression in Nicotiana benthamiana Enhances Tobacco Curly Shoot Virus and Its Betasatellite Co-Infection.

Jiang Du,Mingjun Li,Hussein Ghanem,Ling Qing,Rui Wu,Gentu Wu,Zhuoying Liu,Miao Sun

doi:10.3390/v12040392

Abstract

MicroRNAs (miRNAs) are non-coding but functional RNA molecules of 21–25 nucleotides in length. MiRNAs play significant regulatory roles in diverse plant biological processes. In order to decipher the relationship between nbe-miR1919c-5p and the accumulations of tobacco curly shoot virus (TbCSV) and its betasatellite (TbCSB) DNAs, as well as viral symptom development, we investigated the function of nbe-miR1919c-5p during TbCSV and TbCSB co-infection in plants using a PVX-and a TRV-based short tandem target mimic (STTM) technology. Suppression of nbe-miR1919c-5p expression using these two technologies enhanced TbCSV and TbCSB co-infection-induced leaf curling symptoms in Nicotiana benthamiana plants. Furthermore, suppression of nbe-miR1919c-5p expression enhanced TbCSV and TbCSB DNA accumulations in the infected plants. Our results can advance our knowledge on the nbe-miR1919c-5p function during TbCSV and TbCSB co-infection.

Highlights

Plant microRNAs are 21–25 nucleotides long and noncoding small RNAs, which can negatively regulate their target gene expression upon binding to mRNA sequences [1]
Our previous study had shown that the expression of nbe-miR1919c-5p was down-regulated in the tobacco curly shoot virus (TbCSV)/TbCSB co-infected N. benthamiana plants
Results of qPCR showed that the levels of TbCSV and TbCSB DNAs in both inoculated and systemic leaves of qPCR showed that the levels of TbCSV and TbCSB DNAs in both inoculated and systemic leaves harvested from the tobacco rattle virus (TRV)-M1919+TbCSV/TbCSB-inoculated plants were much higher compared with harvested from the TRV-M1919+TbCSV/TbCSB-inoculated plants were much higher compared with the TRV+TbCSV/TbCSB-inoculated plants (Figure 3E,F)

Summary

Introduction

Plant microRNAs (miRNAs) are 21–25 nucleotides (nt) long and noncoding small RNAs, which can negatively regulate their target gene expression upon binding to mRNA sequences [1]. Numerous studies have shown that through regulation of gene expression, miRNAs dictate many biological processes, including hormone homeostasis, leaf morphogenesis, root development, and plant responses to abiotic and/or biotic stresses [2,3,4,5,6,7]. Plant viruses are known to cause various disease symptoms: mosaic, leaf malformation, and stunting in infected plants. Four distinct begomoviruses: African cassava mosaic virus (ACMV), cabbage leaf curl virus (CbLCuV), tomato yellow leaf curl virus (TYLCV), and cotton leaf curl multan virus plus its betasatellite (CLCuV/CLCuMB), have been shown to regulate the expressions of ten different miRNAs in N. benthamiana plants [17]. Because the patterns of miRNA regulations by the four begomoviruses are different, it was speculated that different miRNAs can control different types and severity of disease symptoms in the infected plants [17]

Methods

Results

Conclusion