New discovery sheds light on how melon crops resist CMV virus

A new study led by Ana Montserrat Martín-Hernández, IRTA researcher at CRAG, has identified a protein that could make melons resistant to the destructive virus cucumber mosaic virus (CMV). This pathogen can infect over 1200 plant species, including important crops like cucumbers and melons, and has been a persistent problem for farmers worldwide. In this work published in Plant Physiology, CRAG researchers have found that mutations in a gene called CmVPS41 might control the resistance to CMV in Nicotiana benthamiana.

CmVPS41 protein is responsible for transporting proteins throughout the plant cell to the vacuole. By examining the protein's behaviour in both susceptible and resistant melon varieties, the researchers found that in the resistant types CmVPS41 was uniformly distributed throughout the cytoplasm and nucleus. However, in susceptible varieties, small channels which researchers referred to as transvacuolar strands were detected passing through the vacuoles, which are structures that allow material to pass through the vacuole membrane. While the existence of these transvacuolar strands was already known, researchers have found that these structures appear in susceptible melon varieties but not in resistant ones, which can be an important key to understanding how the virus infects the susceptible variety and how the resistant variety resists the infection.

Three-dimensional reconstruction of the transvascuolar strands.

This suggests that the distribution of CmVPS41 may include structures that facilitate CMV infection, and that the re-localization of CmVPS41 during viral infection could be an important target for future strategies to confer resistance in breeding programs.

Since CmVPS41 plays a significant role in melon resistance to CMV, further research will be conducted to uncover the protein's specific mechanism of action. By identifying the role of this regulator in cell trafficking, scientists can work towards developing new strategies to prevent the virus from spreading. This research also opens up new avenues for exploring the interactions between viral proteins and host cells, which could have implications for fighting against other plant viruses in the future.

«This study's findings provide valuable insights into the molecular mechanisms of melon virus resistance and could lead to the development of new disease-resistant crop varieties. With the global population continuing to grow, the need for sustainable agriculture practices has never been more important. This research is a promising step towards ensuring food security and sustainability for future generations.», says Ana Montserrat Martín-Hernández, leader of the research.

By understanding how CmVPS41 works and how mutations in this gene can affect resistance, researchers could develop new varieties of melons that are better equipped to resist the virus. This research also highlights the important role that genetics and protein structure play in plant resistance to disease and provides new opportunities for research in plant breeding and genetics. The discovery of this resistance mechanism could have important implications for melon farmers worldwide, as it could provide a new way to fight against CMV infections.

Reference article

Núria Real, Irene Villar, Irene Serrano, Cèlia Guiu-Aragonés, Ana Montserrat Martín-Hernández. Mutations in CmVPS41 controlling resistance to cucumber mosaic virus display specific subcellular localization, Plant Physiology, 2022;, kiac583, https://doi.org/10.1093/plphys/kiac583.

About the authors and funding of the study

This work was supported by the grants AGL2015-64625-C2-1-R and RTI2018-097665-B-C2, from the Spanish Ministry of Economy and Competitiveness (cofunded by FEDER funds) and by the CERCA Programme/Generalitat de Catalunya. The authors acknowledge financial support from the Spanish Ministry of Science and Innovation-State Research Agency (AEI), through the ″Severo Ochoa Programme for Centres of Excellence in R&D″ 2016-2019 (SEV-2015-0533) and CEX2019-000902-S.