Geminivirus Resistance: A Minireview

Abstract

A continuing challenge to crop production worldwide is the spectrum of diseases caused by geminiviruses, a large family of small circular single-stranded DNA viruses. These viruses are quite diverse, some containing mono-or bi-partite genomes, and infecting a multitude of monocot and dicot plants. There are currently many efforts directed at controlling these diseases. While some of the methods include controlling the insect vector using pesticides or genetic insect resistance (Rodrí guez-Ló pez et al., 2011), this review will focus on the generation of plants that are resistant to geminiviruses themselves. Genetic resistance was traditionally found by surveying the wild relatives of modern crops for resistance loci; this method is still widely used and successful. However, the quick rate of virus evolution demands a rapid turnover of resistance genes. With better information about virus-host interactions, scientists are now able to target early stages of geminivirus infection in the host, preventing symptom development and viral DNA accumulation.

Molecular underpinnings of ssDNA specificity by Rep HUH-endonucleases and implications for HUH-tag multiplexing and engineering

“…Characterization of the Rep/ssDNA interface provides a platform to model other Rep ssDNA interfaces as well as an avenue to explore disruption of the interface for antiviral treatments of plant and human Rep-mediated viral infections ( 51 ). Billions of dollars worldwide are lost in agriculture every year from the decimation of crops such as tomatoes, cassava, cotton, and beans by geminivirus infection ( 52 ).…”

“…In a human disease context, parvovirus B19 human infections can lead to serious or fatal outcomes for a fetus ( 53 , 54 ) and are associated with autoimmune diseases in adults ( 21 , 22 ). This has sparked treatment and vaccine development ( 55 ), however present antiviral strategies, both viral protein interfering and gene silencing approaches, are either minimally effective or are eventually subverted by conferred resistance from a rapidly evolving viral genome ( 51 , 56–60 ). Development of antivirals specifically targeting the ssDNA binding of Reps could more effectively retain long-term resistance.…”

A recessive gene pepy-1 encoding Pelota confers resistance to begomovirus isolates of PepYLCIV and PepYLCAV in Capsicum annuum

“…Begomoviruses, transmitted by white ies, have emerged as serious limitations to the cultivation of a wide variety of crops worldwide (Navas-Castillo et al, 2011;Rojas et al 2018). This has motivated researchers and breeders to identify begomovirus resistant sources and to conduct genetic mapping of resistance loci in various crops such as tomato, pepper, melon (Cucumis melo), squash (Cucurbita moschata), common bean (Phaseolus vulgaris), cassava (Manihot esculenta), and cotton (Gossypium hirsutum) (Blair and Morales 2008;Lapidot and Levin 2017;Sáez et al 2017Sáez et al , 2020Beam and Ascencio-Ibáñez 2020;Thakur et al 2020;Zaidi et al 2020). To the best of our knowledge, tomato Ty-1/Ty-3/Ty-3a (encoding RDR), Ty-2 (encoding an NB-LRR protein), and ty-5 (encoding Pelota) are the only begomovirus resistance genes cloned to date (Verlaan et al 2013;Lapdot et al 2015;Yamaguchi et al 2018).…”

Morphological response and genetic variability of four species of chili pepper (Capsicum spp.) under infection of pepper yellow leaf curl virus

“…In assembling disease-resistant plants, apart from focusing on plant resistance, other traits that are not directly related also need to be developed to support increased yields and product quality. Sources of diversity are increasingly being explored, not only limited to the same species or commodity but also from other commodities (Beam and Ascencio-Ibanez 2020). Evaluation of various species becomes important to be carried out to obtain good sources of morphological, agronomic, and resistance character.…”