Sulfoxaflor Alters Bemisia tabaci MED (Hemiptera: Aleyrodidae) Preference, Feeding, and TYLCV Transmission

Tomato yellow leaf curl virus: Characteristics, influence, and regulation mechanism

Tomato yellow leaf curl virus (TYLCV), a DNA virus belonging to the genus Begomovirus, significantly impedes the growth and development of numerous host plants, including tomatoes and peppers. Due to its rapid mutation rate and frequent recombination events, achieving complete control of TYLCV proves exceptionally challenging. Consequently, identifying resistance mechanisms become crucial for safeguarding host plants from TYLCV-induced damage. This review article delves into the global distribution, dispersal patterns, and defining characteristics of TYLCV. Moreover, the intricate interplay between TYLCV and various influencing factors, such as insect vectors, susceptible host plants, and abiotic stresses, plays a pivotal role in plant-TYLCV interactions. The review offers an updated perspective on recent investigations focused on plant response mechanisms to TYLCV infection, including the intricate relationship between TYLCV, whiteflies, and regulatory factors. This comprehensive analysis aims to establish a foundation for future research endeavors exploring the molecular mechanisms underlying TYLCV infection and the development of plant resistance through breeding programs.

Sublethal Effects of Imidacloprid on Fecundity, Apoptosis and Virus Transmission in the Small Brown Planthopper Laodelphax striatellus

Laodelphax striatellus damages plants directly through sucking plant sap and indirectly as a vector of rice stripe virus (RSV), resulting in serious losses of rice yield. It is one of the most destructive insects of rice in East Asia. Insecticides are primarily used for pest management, but the sublethal concentrations of insecticides may benefit several insects. The present research attempted to explore the effects of sublethal concentrations of imidacloprid on the fecundity, apoptosis and RSV transmission in the viruliferous SBPH. The results showed that the fecundity of SBPH was significantly increased after treatment with the LC₁₀ dose of imidacloprid, while the LC₃₀ dose of imidacloprid reduced the fecundity compared with the control. To further investigate the underlying mechanism of increased fecundity after exposure to the LC₁₀ dose of imidacloprid, we examined the expression levels of vitellogenin (Vg), Vg receptor (VgR) and caspases in the ovaries of SBPH, and observed the apoptosis by terminal deoxynucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling (TUNEL). qRT-PCR results indicated that the expression levels of Vg, VgR and four caspase genes were all significantly increased by the LC₁₀ dose of imidacloprid, and TUNEL assays suggested that the frequency of apoptosis was significantly higher in the SBPH treated by the LC₁₀ dose of imidacloprid, suggesting a potential correlation between the increased fecundity and the apoptosis of SBPH ovarioles. Additionally, the expression levels of RNA3 and capsid protein (CP) were both increased significantly by the LC₁₀ dose of imidacloprid, whereas were decreased by the LC₃₀ dose of imidacloprid compared to the control. Therefore, this study clarifies the mechanisms of sublethal effects of imidacloprid on viruliferous SBPH and could be used to optimize pest control strategies.