Dissecting Papaya Leaf Curl Disease (PLCD) Complex and Assessing its Potential for siRNA Based Targeting

Abstract

Carica papaya L. (papaya) production is severely affected by leaf curl and related disease symptoms caused by various species of begomoviruses making it a complex disease. Papaya leaf curl disease (PLCD) complex has broad host range and high genetic variability, therefore, the study was conducted to dissect the genetic complexity of PLCD. Begomoviruses infect various host crops and weeds associated with cultivation of papaya. Intermixing among their genomes and mutational forces drive molecular variability in the disease complex, which enables them to expand their host range. This molecular variability is important determinant when RNA interference based strategy is applied against these viruses. In this study, we have observed that the broad host range of PLCD complex viral components is due to high frequency of recombination events that took place at different time scales. The rise of recombinants led to host variability resulting in similar symptomatic infection over new crops and weeds in nearby fields. Therefore, we have taken into account molecular variability and recombination regions of the viral genome as the targets for providing resistance against these viruses, thus, preventing serious implications of similar diseases spreading over to new hosts.