Bottom-up effects of UV-B radiation on tobacco (Nicotiana tabacum)-aphid (Myzus persicae) interactions

Bottom-up effects modulated by abiotic factors play an important role in influencing plant-herbivorous insect interactions. Ultraviolet-B (UV-B) radiation is an important factor that regulates plant resistance to agricultural arthropod pests. Yet, addressing the bottom-up effects of UV-B radiation on plant-insect interactions by a holistic approach from insect development and behavior to plant metabolome analyses has rarely been documented. This study examined how UV-B radiation influences tobacco plant (Nicotiana tabacum)-aphid (Myzus persicae) interactions. Tobacco seedlings were irradiated with a UV-B lamp for 14 consecutive days, with a daily exposure time of 2 h (UV2h) and 4 h (UV4h). Here, UV-B radiation was found to enhance the resistance of tobacco plants to M. persicae in terms of the development, body size, population growth, and feeding behavior of the pest. Broad targeted metabolome analyses revealed that the tobacco plants produced higher concentrations of defensive secondary compounds, such as salicylic acid, rutin, kaempferol derivatives, and isochlorogenic acid B, after exposure to UV-B radiation. These results suggest that UV-B radiation enhanced the resistance of tobacco to M. persicae; thus, exposing seedlings to UV-B radiation could be utilized to enhance pest control.