An Overview of Chili Leaf Curl Disease: Molecular Mechanisms, Impact, Challenges, and Disease Management Strategies in Indian Subcontinent.

Leaf curl disease in a chili plant is caused mainly by Chili leaf curl virus (ChiLCV) (Family: Geminiviridae, Genus: Begomovirus). ChiLCV shows a widespread occurrence in most of the chili (Capsicum spp.) growing regions. ChiLCV has a limited host range and infects tomatoes (Solanum lycopersicum), potatoes (S. tuberosum), and amaranth (Amaranthus tricolor). The virus genome is a monopartite circular single-stranded DNA molecule of 2.7 kb and associated with α and ß-satellites of 1.3 and 1.4 kb, respectively. The virus genome is encapsulated in distinct twinned icosahedral particles of around 18-30 nm in size and transmitted by Bemisia tabaci (Family: Aleyrodidae, Order: Hemiptera). Recently, bipartite begomovirus has been found to be associated with leaf curl disease. The leaf curl disease has a widespread distribution in the major equatorial regions viz., Australia, Asia, Africa, Europe, and America. Besides the PCR, qPCR, and LAMP-based detection systems, recently, localized surface-plasmon-resonance (LPSR) based optical platform is used for ChiLCV detection in a 20-40 µl of sample volume using aluminum nanoparticles. Management of ChiLCV is more challenging due to the vector-borne nature of the virus, therefore integrated disease management strategies need to be followed to contain the spread and heavy crop loss. CRISPR/Cas-mediated virus resistance has gained importance in disease management of DNA and RNA viruses due to certain advantages over the conventional approaches. Therefore, CRISPR/Cas system-mediated resistance needs to be explored in chili against ChiLCV.