Abstract:
Trichomes are plant-derived external appendages that play a crucial role in plant stress resistance. This study examined the spatial distribution characteristics of epidermal trichomes and conducted insect resistance tests on nine potato varieties (lines) with high, medium, and low trichome densities. Using a comprehensive targeted metabolomics approach, we measured the two varieties (lines) with the greatest differences in trichome density, ‘Tianshu 15’ and ‘S10-510’, and compared their metabolic composition differences. Using a comprehensive targeted metabolomics approach, we selected two varieties (lines) with contrasting trichome densities, ‘Tianshu 15’ and ‘S10-510’, for further analysis. We then compared their metabolic profiles to identify compositional differences. The results show: The trichomes on potato leaves exhibit polymorphic distribution patterns, with significantly lower trichome density on the adaxial surface compared to the abaxial surface. The percentage of insect-damaged leaves and the number of insects per hundred leaves showed a negative correlation with both non-glandular trichomes and glandular trichomes on the adaxial surface, as well as with non-glandular trichomes and glandular trichomes on the abaxial surface. Varieties (lines) with high trichome density exhibit greater insect resistance than those with medium trichome density, and those with low trichome density. There is a significant correlation between trichome density and insect resistance. Broad-targeted metabolomics detected a total of
1717 distinct metabolite species. Among these, phenolic acids, lipids, alkaloids, and flavonoids constituted the most abundant classes, accounting for 16.7%, 14.91%, 12.75%, and 12.06% of the total detected metabolites, respectively. Significant metabolic differences were observed between the ‘Tianshu 15’ and ‘S10-510’ varieties, with 446 differentially expressed metabolites identified. Among these, 238 metabolites showed significant upregulation, while 208 metabolites exhibited significant downregulation. The top five pathways with the highest enrichment of differentially abundant metabolites were secondary metabolites, ABC transporters, tryptophan metabolism, flavone and flavanol biosynthesis, and glycolysis. This study proⅥdes valuable insights for research on the mechanisms of pest and disease resistance in potatoes and for the breeding of new varieties (lines).