Chapter 35 - Recent advances in begomovirus research in India

Abstract

Begomovirus, a large genus of the family Geminiviridae, consists of 410 species that infect various plants worldwide. The genus contains single-stranded circular DNA and is encapsidated in geminate particles. Viruses in this genus include whiteflies (Bemisia tabaci), which is transmitted in a circulative persistent manner and causes a significant reduction in the yield of economically important crops in India. Detection and molecular characterization of begomoviruses species—such as mung bean yellow mosaic virus, black gram yellow mosaic virus, bhendi yellow vein mosaic virus, chilli leaf curl virus, cotton leaf curl virus, pumpkin yellow vein mosaic virus, tomato leaf curl New Delhi virus, tobacco leaf curl virus, tomato yellow leaf curl virus, and papaya leaf curl virus—have been done with regard to phylogenetic analyses, infectivity on host plants, DNA replication, transgenic resistance, promoter analysis, and development of virus-based gene-silencing vectors using several techniques. Begomoviruses were detected using polymerase chain reaction (PCR) detection of geminivirus using degenerate primer, reverse transcription PCR (RT-PCR), real time PCR, rolling-circle amplification PCR (RCA-PCR assay), RCA, and microarray/DNA chip. Begomovirus infections can be prevented by controlling vectors, developing virus-free planting materials, developing immune or resistant varieties, use of culture practices, following quarantine regulations, and adapting modern methods, including pathogen-derived resistance (PDR), RNA interference (RNAi)–mediated resistance, and ribozyme-mediated resistance. In this chapter, we discuss modern methods of control, including PDR, RNAi-mediated resistance, ribozyme-mediated resistance, short, interfering RNA (siRNA)–mediated resistance, and artificial transacting siRNA (tasiRNA) resistance.