Plant pathogens are the unseen enemy. According to the Encyclopedia of Microbiology, plant disease is defined as a state of local or systemic abnormalities affecting the physiological functions of a plant, leading to a chronic irritation caused by phytopathogenic organisms (biotic or infectious disease agents).
Plants are also prone to abiotic diseases. These are caused by external conditions that don't typically spread plant to plant; however, they are everywhere. Some common examples are soil and nutritional deficiencies, salt accumulation, and environmental factors such as ice and fire.
Currently, an estimated 4000 viruses are recognized worldwide, of which about 1000 affect plants. The study of plant pathology allows for managing viral diseases' negative impacts on crops and recognizing virus-host interactions, enabling scientists to understand the root of conditions responsible for crop loss worldwide.
Recently, eight laboratories across five European countries independently contributed to newly published research on Physostegia Chlorotic Mottle Virus (PhCMoV); the study was a colossal undertaking. Sharing information on plant diseases like this will allow researchers to identify early detection signs, efficiently characterize the diseases, and eventually manage future disease outbreaks.
PhCMoV, first identified in 2018 in Austria, was detected growing on tomatoes in Germany and Serbia. Tin both cases, the crops were showing mottling and ripening abnormalities. PhCMoV is from the Rhabdoviridae family of single-strand RNA viruses that insects transmit.
In the study, PhCMoV was identified in eight countries. They took healthy plants to act as a host while being inoculated with the disease to correlate symptoms in controlled conditions.
A total of nine species were analyzed across seven families of natural plant hosts. Samples were collected from Germany, Belgium, France, the Netherlands, and Slovenia, with some additional symptomatic plants from Russia and Romania submitted for diagnostics. Plant samples range from tomato, eggplant, cucumber, potato, and sweet potato variations.
After they extracted the genomes across these regions, they found that tomatoes showed an uneven ripening pattern with excessive mottling of the fruit but not on the leaves. Similar results were displayed for eggplants, where the leaves also showed some yellowing and vein clearing, unlike the tomatoes. Cucumbers showed signs of mottling, deformities, variable color changes, and leaf curling.
Plant diseases often exhibit symptoms similar to other plant diseases, like zoonotic and human diseases. Genomic data and the characterization of plant pathology can fuel future research in viral biodiversity. Examining virus-host-vector systems, or the study of Viromics is vital to identifying potential pathogens that could threaten plants and animals.
Sources: Science Direct, UNL, EurekAlert, APS, NCBI, Springer Nature
Figure 1: Showing pictures of natural Physostegia chlorotic mottle virus (PhCMoV)-infected plants. Copyright © 2022 The Author(s): Temple et al. 2022.
Coline Temple, Arnaud G. Blouin, Kris De Jonghe, Yoika Foucart, Marleen Botermans, Marcel Westenberg, Ruben Schoen, Pascal Gentit, Michèle Visage, Eric Verdin, Catherine Wipf-Scheibel, Heiko Ziebell, Yahya Z. A. Gaafar, Amjad Zia, Xiao-Hua Yan, Katja R. Richert-Pöggeler, Roswitha Ulrich, Mark Paul S. Rivarez, Denis Kutnjak, Ana Vučurović, and Sébastien Massart
