Chilli veinal mottle virus (ChiVMV) has been reported to infect Solanaceous crops in recent years, causing severe damage to crop yields. Previous studies have demonstrated that various nutrient elements can improve plant resistance through different strategies. However, there are no reports on the regulation of the resistance to ChiVMV infection by nutrient elements in tobacco. In this study, we found that viral infection decreased calcium (Ca) content in tobacco plants. Interestingly, exogenous application of Ca(NO 3 ) 2 improved tobacco resistance to ChiVMV infection. Meanwhile, the key genes and pathways of Ca-induced resistance to ChiVMV infection were verified through transcriptome sequencing analysis. Among them, NtTPS9–2 related to trehalose synthesis and NtEIN3–5 related to ethylene signal transduction were up-regulated in ChiVMV-infected plants and regulated by Ca spraying. Further research demonstrated that silencing the homologous genes of these two genes enhanced the resistance of Nicotiana benthamiana to ChiVMV infection. Our research reveals that Ca element is involved in the regulatory network of viral disease resistance in tobacco, providing a worthy foundation for the cultivation management and molecular design breeding of tobacco plants. • Foliar application of Ca could inhibit ChiVMV infection in tobacco. • The gene regulatory pathways of Ca-induced tobacco resistance to ChiVMV infection were identified. • NbTPS and NbEIN3 played positive roles in resistance to ChiVMV infection.
Guo et al. (Tue,) studied this question.