Hair-like Structures and Special Genes Help Grapevines Resist Insect Damage

Jenn Hoskins
27th June, 2024

Hair-like Structures and Special Genes Help Grapevines Resist Insect Damage

Image Source: Natural Science News, 2024

Key Findings

  • The study, conducted at The Ohio State University, found that 'GREM4' grapevines are more resistant to Japanese beetle herbivory than 'PN40024'
  • 'GREM4' grapevines have higher leaf trichome densities, which deter beetle feeding
  • 'GREM4' also has a higher expression of defense-related genes, contributing to its robust resistance
Grapevine (Vitis) is a globally significant fruit crop, but insect herbivory poses a substantial threat to yields. Understanding the mechanisms behind insect herbivory resistance is crucial for developing more resilient grapevine varieties. A recent study conducted by researchers at The Ohio State University[1] explored the resistance of Vitis labrusca acc. 'GREM4' and Vitis vinifera cv. 'PN40024' to Japanese beetle (Popillia japonica) herbivory, uncovering key morphological and genetic factors that contribute to this resistance. The study found that 'GREM4' exhibited greater resistance to Japanese beetle herbivory compared to 'PN40024'. This was determined through both choice and no-choice herbivory assays over periods ranging from 30 minutes to 19 hours. One of the primary findings was that 'GREM4' had significantly higher leaf trichome densities than 'PN40024', and beetles showed a preference for feeding on leaf surfaces with fewer trichomes. However, even when leaves from both species with similar trichome densities were tested, 'GREM4' sustained less damage, indicating that additional factors beyond trichomes were at play. To delve deeper into these additional factors, the researchers performed comparative transcriptomic analyses. They discovered that 'GREM4' had a higher constitutive expression of genes related to defense response and secondary metabolite biosynthesis, even before herbivory began. Upon herbivory, 'GREM4' exhibited a more extensive response, with 690 differentially expressed genes compared to 502 in 'PN40024'. The up-regulated genes in 'GREM4' were particularly enriched in pathways related to terpene biosynthesis, flavonoid biosynthesis, phytohormone signaling, and disease defense, suggesting a robust and multi-faceted defense mechanism. These findings align with previous research that has shown the importance of genetic and morphological traits in plant resistance to biotic stresses. For instance, a study on downy mildew resistance in various Vitis species highlighted the significance of pathogen genotype and host species in determining resistance levels[2]. Similarly, research on powdery mildew resistance demonstrated genetic variation in ontogenic resistance across different Vitis species[3]. The current study builds on these findings by identifying specific genetic and morphological traits that contribute to insect herbivory resistance in grapevines. The role of mitogen-activated protein kinases (MAPKs) in orchestrating defense responses to insect herbivory has also been well-documented[4]. In this context, the current study's identification of genes involved in phytohormone signaling and disease defense in 'GREM4' further underscores the complexity of plant defense mechanisms. In conclusion, the study conducted by The Ohio State University suggests that 'GREM4' grapevines possess a combination of morphological traits, such as high trichome density, and genetic traits, including the constitutive and inducible expression of defense-related genes, which contribute to their resistance to Japanese beetle herbivory. These findings not only enhance our understanding of plant-insect interactions but also provide valuable insights for breeding programs aimed at developing grapevine varieties with improved resistance to insect herbivory.

GeneticsBiochemPlant Science

References

Main Study

1) Trichomes and unique gene expression confer insect herbivory resistance in Vitis labrusca grapevines.

Published 27th June, 2024

Journal: BMC plant biology

Issue: Vol 24, Issue 1, Jun 2024

Related Studies

2) Variation Within and Between Vitis spp. for Foliar Resistance to the Downy Mildew Pathogen Plasmopara viticola.

https://doi.org/10.1094/PDIS-92-11-1577

3) Ontogenic Resistance to Uncinula necator Varies by Genotype and Tissue Type in a Diverse Collection of Vitis spp.

https://doi.org/10.1094/PDIS-92-7-1067

4) MAPK signaling: a key element in plant defense response to insects.

https://doi.org/10.1111/1744-7917.12128


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