A Pathogen-Responsive Gene Cluster for Highly Modified Fatty Acids in Tomato.

Area of Science:

• Plant biochemistry
• Molecular biology
• Chemical ecology

Background:

• Plants synthesize complex fatty acids in response to biotic stress.
• Decorated fatty acids play roles in pathogen defense, but their biosynthesis is poorly understood.
• Falcarindiol, an acetylenic lipid found in several plants, exhibits antifungal and anticancer properties.

Purpose of the Study:

• To identify the biosynthetic pathway of falcarindiol in plants.
• To elucidate the role of specific genes in falcarindiol production.
• To investigate the contribution of falcarindiol to plant defense mechanisms.

Main Methods:

• Untargeted metabolomics and RNA sequencing in tomato (Solanum lycopersicum).
• Heterologous expression of initial biosynthetic steps.
• Generation of transgenic tomato mutants for pathway analysis.

Main Results:

• A novel biosynthetic gene cluster essential for falcarindiol production was identified in tomato.
• Reconstitution experiments confirmed the cluster's role in falcarindiol biosynthesis.
• Transgenic tomato lines exhibited altered falcarindiol levels and modified resistance to fungal and bacterial pathogens.

Conclusions:

• A specific gene cluster governs the biosynthesis of the alkynyl lipid falcarindiol in tomato.
• Falcarindiol biosynthesis contributes to plant defense against microbial pathogens.
• This study provides key insights into plant lipid modification and defense strategies.