Water deficit enhances the transmission of plant viruses by insect vectors

Abstract

Drought is a major threat to crop production worldwide and is accentuated by global warming. Plant responses to this abiotic stress involve physiological changes overlapping, at least partially, the defense pathways elicited both by viruses and their herbivore vectors. Recently, a number of theoretical and empirical studies anticipated the influence of climate changes on vector-borne viruses of plants and animals, mainly addressing the effects on the virus itself or on the vector population dynamics, and inferring possible consequences on virus transmission. Here, we directly assess the effect of a severe water deficit on the efficiency of aphid-transmission of the Cauliflower mosaic virus (CaMV) or the Turnip mosaic virus (TuMV). For both viruses, our results demonstrate that the rate of vector-transmission is significantly increased from water-deprived source plants: CaMV transmission reproducibly increased by 34% and that of TuMV by 100%. In both cases, the enhanced transmission rate could not be explained by a higher virus accumulation, suggesting a more complex drought-induced process that remains to be elucidated. The evidence that infected plants subjected to drought are much better virus sources for insect vectors may have extensive consequences for viral epidemiology, and should be investigated in a wide range of plant-virus-vector systems.

Drought stress affects response of phytopathogen vectors and their parasitoids to infection‐ and damage‐induced plant volatile cues

“…This prediction holds only if the bacterial transmission rate is similar between drought‐stressed and well‐watered plants. A recent study demonstrated that transmission of Cauliflower mosaic virus and Turnip mosaic virus to turnip Brassica rapa by the aphid M. persicae increased with drought stress (van Munster et al ., ). Similar research should be conducted on citrus and C Las to have a better understanding of how drought stress affects spread of this pathogen.…”

Genome‐wide association study reveals new loci involved in Arabidopsis thaliana and Turnip mosaic virus (TuMV) interactions in the field

“…Impacts of temperature, water deficit and variable light also influence responses to viruses in A. thaliana (Xu et al ., ; Hily et al ., ). In turnip, drought was shown to enhance the rate of transmission for Cauliflower mosaic virus (CaMV) and TuMV (van Munster et al ., ), whereas the opposite was found in transmission of Turnip yellows virus (TuYV) in A. thaliana (Yvon et al ., ). Together, these results highlight the need to capture the variable stresses within and between days that typify natural environments.…”

“…Plant viruses, the major pathogens causing emerging infectious disease (Anderson et al, 2004), exhibit environmental sensitivity of diverse components of their epidemics and thus represent a relatively large threat in the context of global change. For example, recent studies have reported the impacts of high temperatures, water deficit, variable light and CO 2 concentration changes on both rates of infection and transmission efficiencies of viruses (Xu et al, 2008;Nancarrow et al, 2014;Chung et al, 2015;Hily et al, 2016;van Munster et al, 2017;Trebicki et al, 2017;Yvon et al, 2017).…”

Management of Plant Disease Epidemics with Irrigation Practices

“…Irrigation water does not affect the several viral pre-infection stages that are found within the fungi and bacteria life cycles. When lacking or in excess, water and irrigation may cause physiological host changes, which may accentuate or attenuate symptoms or alter the relationship of the vector with the virus and the host plant [43]. In some cases, the virus may protect its host from severe drought by avoiding irreversible wilt, as reported by Xu et al [44].…”