A Reduced Starch Level in Plants at Early Stages of Infection by Viruses Can Be Considered a Broad-Range Indicator of Virus Presence

Abstract

The diagnosis of virus infection can facilitate the effective control of plant viral diseases. To date, serological and molecular methods for the detection of virus infection have been widely used, but these methods have disadvantages if applied for broad-range and large-scale detection. Here, we investigated the effect of infection of several different plant RNA and DNA viruses such as cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), potato virus X (PVX), potato virus Y (PVY) and apple geminivirus on starch content in leaves of Nicotiana benthamiana. Analysis showed that virus infection at an early stage was generally associated with a reduction in starch accumulation. Notably, a reduction in starch accumulation was readily apparent even with a very low virus accumulation detected by RT-PCR. Furthermore, we also observed that the infection of three latent viruses in propagative apple materials was associated with a reduction in starch accumulation levels. Analysis of transcriptional expression showed that some genes encoding enzymes involved in starch biosynthesis were downregulated at the early stage of CMV, TMV, PVX and PVY infections, suggesting that virus infection interferes with starch biosynthesis in plants. Our findings suggest that assessing starch accumulation levels potentially serve as a broad-range indicator for the presence of virus infection.

Effect of infection of potato plants by Potato virus Y (PVY), Potato virus S (PVS), and Potato virus M (PVM) on content and physicochemical properties of tuber starch

“…PVM, PVY, and PVS samples exhibit higher amylose content than the virus‐free control sample; the highest amount of amylose (22.01%) was noted in PVY starch. According to Lal et al (2021), ToLCNDV‐potato infection caused changes to amylose content in starch, probably due to the effect of viruses on the biochemical and physiological process of starch accumulation in tubers, similar to the procedures described by Zhao et al, 2022.…”

“…As noted before, researchers found a decrease in the starch content in the tubers of potatoes infected with the virus (Blotskaya, 2000; Hou et al, 2020; Lal et al, 2021; Zhao et al, 2022; Amelyushkina, 2018; Rusetsky, 2006). The dry matter of tubers and starch content decrease in tubers of potato plants infected by PVM, PVS, and PVY.…”

“…Infection by plant viruses leads to biochemical and physiological changes in photosynthesis, CO 2 assimilation, and starch accumulation (Trethewey & Smith, 2000). It is noted that viruses usually suppress the accumulation of starch in the leaves of plants at an early stage of infection (Zhao et al, 2022). Infection of potato plants with PLRV, PVY, PVS, and PVM leads to a decrease in the starch content in tubers by 0.5%–9% compared to uninfected tubers (Blotskaya, 2000).…”

Pathogen-triggered metabolic adjustments to potato virus Y infection in potato

“…Therefore, the observed downregulation of G6P and F6P in Russet Burbank may be an indication of disruption in energy production, as well as impaired starch biosynthesis, which is considered an indicator of successful virus infection ( Zhao et al., 2022 ). In addition, G6P and F6P depletion may indicate a repression of the glycolytic-PPP shunt.…”

A review of the interaction between potassium nutrition and plant disease control

“…The authors hypothesized that cucumber mosaic virus, tobacco mosaic virus, and potato viruses caused this reduction in starch content in the leaves through manipulation of the plant metabolism to promote the survival of the virus. While K nutrition was not considered in this study, it could be hypothesized that a viral pathogen attack on a K‐deficient plant may have increased rates of infection because of the compounding effects of reduced starch synthesis due to both the K deficiency (Cui & Tcherkez, 2021) and the virus manipulation of the plant metabolism (Shalitin et al., 2002; Zhao et al., 2022), which may combine to promote infection. However, the K deficiency cannot be severe enough to kill the host plant, as viral pathogens rely on their living host.…”