Tomato Yellow Leaf Curl Virus (TYLCV) Promotes Plant Tolerance to Drought

Abstract

A growing body of research points to a positive interplay between viruses and plants. Tomato yellow curl virus (TYLCV) is able to protect tomato host plants against extreme drought. To envisage the use of virus protective capacity in agriculture, TYLCV-resistant tomato lines have to be infected first with the virus before planting. Such virus-resistant tomato plants contain virus amounts that do not cause disease symptoms, growth inhibition, or yield loss, but are sufficient to modify the metabolism of the plant, resulting in improved tolerance to drought. This phenomenon is based on the TYLCV-dependent stabilization of amounts of key osmoprotectants induced by drought (soluble sugars, amino acids, and proteins). Although in infected TYLCV-susceptible tomatoes, stress markers also show an enhanced stability, in infected TYLCV-resistant plants, water balance and osmolyte homeostasis reach particularly high levels. These tomato plants survive long periods of time during water withholding. However, after recovery to normal irrigation, they produce fruits which are not exposed to drought, similarly to the control plants. Using these features, it might be possible to cultivate TYLCV-resistant plants during seasons characterized by water scarcity.

Exploiting Virus Infection to Protect Plants from Abiotic Stresses: Tomato Protection by a Begomovirus

“…Instead of severe, sometimes lethal response for most plant cells, TYLCV promotes the development of a protective homeostasis response in plants exposed to prolonged environmental stresses, favoring the survival of the plant. The down-regulation of stress proteins and metabolites coincides with the stabilization of their patterns, particularly in R-TYLCV tomatoes [ 39 , 41 ]. These stable patterns are maintained not only in shoot, but also in roots of virus-infected tomatoes.…”

“…Comparing uninfected and TYLCV-infected tomatoes grown under conditions of water withholding indicated that virus infection caused a reduced rate of transpiration and a stabilization of plant water balance. This resulted in less water use from soil and promoted plant survival [ 39 , 41 ]. Attenuated transpiration was observed in different tomato cultivars and was ultimately dependent on the presence of the virus.…”

“…TYLCV promoted tomato growth for much longer time compared to uninfected R-GF967 tomatoes. Virus pre-inoculation of the R-GF967, promoted extreme tolerance to drought [ 41 ]. Uninfected tomatoes (S- and R-TYLCV) ceased to grow after two weeks of complete water withholding, while these plants pre-infected with TYLCV continued to grow ( Figure 4 A).…”

Advancement in the molecular perspective of plant-endophytic interaction to mitigate drought stress in plants

“…Apart from endophytic bacteria and fungi, asymptomatic viruses also have important role in alleviating the abiotic stress in plants. Tomato yellow leaf curl virus (TYLCV), belonging to Begomovirus family, has been found to impart tolerance to tomato plant against severe drought stress (Gorovits et al, 2019;Shteinberg et al, 2021). Upon infection, the major TYLCV proteins interact with the heat shock transcription factor HSFA2 and suppress the heat shock response.…”

The potyviral protein 6K2 from Turnip mosaic virus increases plant resilience to drought

“…While plant viruses are best known as obligate parasites and pathogens of their hosts, recent evidence suggests viruses can enhance host survival during drought. For example, many plants have been shown to perform better under drought conditions when infected with viruses, such Brome mosaic virus (BMV), Cucumber mosaic virus (CMV), Cauliflower mosaic virus (CaMV), Tobacco mosaic virus (TMV), Tomato yellow leaf curl virus (TYLCV), or Tobacco rattle virus (TRV) compared to uninfected control plants (Xu et al 2008; Westwood et al 2013; Bergès et al 2018, 2020; Corrales-Gutierrez et al 2020; Shteinberg et al 2021). Virus-induced drought tolerance has been shown using diverse vegetative crops, including rice ( Oryza sativa ), wheat ( Triticum aestivum ), tomato ( Solanum lycopersicum ), pepper ( Capsicum annuum ), watermelon ( Cucumis lanatus ), cucumber ( Cucumis sativus ), and zucchini squash ( Cucurbita pepo ) (Xu et al 2008; Davis, Bosque-Pérez, Foote, Magney & Eigenbrode 2015).…”