# Time-Series Comparative Transcriptome Analyses of Two Potato Cultivars with Different Verticillium Wilt Resistance

## TL;DR

This study compares the transcriptomes of two potato cultivars with different resistance to Verticillium wilt, identifying genes and metabolic pathways linked to resistance.

## Contribution

The study provides the first comprehensive transcriptomic insights into Verticillium wilt resistance in potato.

## Key findings

- VW inoculation caused 14,310 and 21,739 differentially expressed genes in resistant and susceptible potato cultivars, respectively.
- LS8 showed rapid activation of salicylic acid and defense-related metabolites, followed by metabolic reprogramming involving carbohydrate and cell wall biosynthesis.
- Highly expressed StPAL genes and increased PAL activity in LS8 were associated with VW resistance.

## Abstract

Comparative omics analysis offers one of the most direct and effective approaches to gain novel insights into crop traits, facilitating candidate gene identification and crop improvement. Verticillium dahliae causes one of the most globally devastating crop diseases, the Verticillium wilt (VW). However, comparative transcriptome resources regarding VW resistance remain scarce in a major host species potato. To address this knowledge gap, we provide a comprehensive comparative RNA-seq analysis of VW resistance between a VW-resistant and -susceptible potato cultivar (LS8 and SP, respectively). VW inoculation induced dramatic transcriptomic changes, resulting in 14,310 differentially expressed genes (DEGs) in LS8 and 21,739 DEGs in SP. With the time-series analysis, we disentangled the VW-associated transcriptomic responses from those reflected LS8-SP cultivar differences. Particularly, LS8 featured a rapid response of phytohormone salicylic acid and defense-related specialized metabolites at 1 day post inoculation (dpi), followed by large-scale metabolic reprogramming, including carbohydrate and choline metabolism and enhanced biosynthesis of secondary cell wall components (e.g., hemicellulose, xylan, cuticle, suberin, and wax). Furthermore, we identified highly expressed VW-responsive potato phenylalanine ammonia-lyase genes (StPALs) and revealed the higher PAL activities in LS8 associated with VW resistance. Overall, our results provide the first transcriptomic insights into VW resistance in potato and new candidate genes regarding VW resistance.