Effects of light intensity on the susceptibility of Nicotiana tabacum to cucumber mosaic virus

• Published in: Journal of general plant pathology : JGPP Vol. 81; no. 5; pp. 399 - 408
• Main Authors: Chen, Li-Juan, Ren, Han, Deng, Xing-Guang, Li, Ya-Nan, Cha, Wen-Qiong, Lin, Hong-Hui, Xi, De-Hui
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.09.2015; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Cucumber mosaic virus; Cucumbers; Cytomegalovirus; Disease Control; genes; Life Sciences; Light; Light intensity; messenger RNA; Microbiology; Nicotiana tabacum; Oxygen; pathogenesis; pathogenesis-related proteins; Plant diseases; Plant Pathology; Planting density; reactive oxygen species; salicylic acid; signal transduction; Viruses; Light intensity; Cucumber mosaic virus (CMV); Plant defense; Salicylic acid (SA); Reactive oxygen species (ROS)
• ISSN: 1345-2630; 1610-739X
• DOI: 10.1007/s10327-015-0602-2

Disease development in Nicotiana tabacum after inoculation with cucumber mosaic virus (CMV) was accelerated when plants were grown in high light (300 µmol m⁻² s⁻¹, HL) compared with those grown in low light (70 µmol m⁻² s⁻¹, LL). Several characteristic defense reactions, including release of reactive oxygen species, accumulation of salicylic acid (SA), expression of SA-mediated pathogenesis related (PR) proteins and the systemic development of disease, were proved to be light dependent. Plants exposed to HL or medium light (150 µmol m⁻² s⁻¹, ML) had serious oxidative damage caused by CMV infection compared with LL-plants. In addition, the levels of SA and mRNA transcripts for non-expressor of pathogenesis-related gene 1 in CMV-inoculated plants were the highest under LL with decreasing photon flux density. In HL-exposed plants, the expression of PR1 and PR2 were repressed, but the expression of PR5 was not significantly altered, revealing a complex cross talk between light intensity and the SA signaling pathway in regulating N. tabacum response to the infection of CMV. Taken together, our results revealed that increased light intensity reduced the resistance ability of N. tabacum to CMV, correlating with repression of the SA-dependent signaling pathway and a change in the cellular redox status in plants cells.