Abstract

Viruses, as intracellular parasites, rely on the host organism to complete their life cycle. Although over 70% of plant viruses are transmitted by insect vectors, the role of vector energy metabolism on the infection process of insect-borne plant viruses is unclear. In this study, full-length cDNAs of three energy metabolism-related genes (LsATPase,LsMIT13andLsNADP-ME) were obtained from the small brown planthopper (SBPH,Laodelphax striatellus), which transmits theRice stripe virus(RSV). Expression levels ofLsATPase,LsMIT13andLsNADP-MEincreased by 105%, 1120% and 259%, respectively, due to RSV infection. The repression ofLsATPase,LsMIT13orLsNADP-MEby RNAi had no effect on RSV nucleocapsid protein (NP) transcripts or protein levels. The repression ofLsATPasecaused a significant increase inLsMIT13andLsNADP-MEtranscript levels by 230% and 217%, respectively, and the repression ofLsMIT13caused a significant increase inLsNADP-MEmRNA levels. These results suggested that the silencing ofLsATPaseinduced compensatory upregulation ofLsMIT13andLsNADP-ME, and silencingLsMIT13induced compensatory upregulation ofLsNADP-ME. Further study indicated that the co-silencing ofLsATPase,LsMIT13andLsNADP-MEin viruliferous SBPHs increased ATP production and RSV loads by 182% and 117%, respectively, as compared with nonviruliferous SBPHs. These findings indicate that SBPH energy metabolism is involved in RSV infection and provide insight into the association between plant viruses and energy metabolism in the insect vector.Keywords:RSV;Laodelphax striatellus;energy metabolism;ATP synthase;mitochondrial import inner membrane translocases;NAD-dependent malic enzyme