Leaf-galling phylloxera on grapes reprograms host metabolism and morphology

Area of Science:

• Plant-insect interactions
• Molecular biology
• Plant physiology

Background:

• Gall-forming insects induce significant plant phenotypic changes.
• These modifications appear to benefit the parasite through unknown mechanisms.
• The induced phenotype is considered an extension of the parasite.

Purpose of the Study:

• Investigate how the grape phylloxera (Daktulosphaira vitifoliae) manipulates grapevines.
• Characterize the function of induced stomata and their role in carbon transport.
• Analyze the global reconfiguration of primary and secondary metabolism in galled tissues.

Main Methods:

• Tracing assimilated carbon transport to understand stomatal function.
• Transcriptome analysis of gall tissues to infer metabolic changes.
• Gene expression profiling for primary and secondary metabolic pathways.

Main Results:

• Phylloxera induced stomata on the adaxial leaf surface, typically lacking stomata.
• Induced stomata facilitated carbon assimilation and transport into the gall.
• Upregulated gene expression for water, nutrient, mineral transport, glycolysis, and fermentation.
• Downregulated gene expression for nonmevalonate and terpenoid synthesis.
• Upregulated gene expression for shikimate and phenylpropanoid biosynthesis.

Conclusions:

• Phylloxera-induced stomata are functional and part of an extended phenotype.
• Daktulosphaira vitifoliae globally reprograms grape leaf development.
• Metabolic reprogramming favors nutrient mobilization and alters defense investment for gall formation.