Maria Doroteia Campos

With the rising prominence of organic farming systems in European Union countries, motivated by agricultural policies, there is pressure for effective disease management strategies. To address this challenge, the use of plant resistance inducers (PRIs) and elicitors has emerged as a promising approach. In this study, we compared the impact of integrated production with organic agriculture farming practices, specifically applying PRIs and elicitors in the latter, on the expression levels of stress-responsive genes in two grapevine cultivars, ‘Alicante Bouschet’ and ‘Trincadeira’. Our findings revealed that the organic farming system led to upregulation of eight of the 12 studied genes in at least one cultivar, indicating a significant influence of production mode. The upregulated genes were associated with plant stress-responsive genes (PR1, PR2, PR4, and TLP9), sugar metabolism (HT5), phenylpropanoids (STS1), enzymes related to jasmonic acid synthesis and response to biotic stresses, respectively (LOX, PER42). Also, the ‘Alicante Bouschet’ cultivar consistently displayed significantly higher levels of transcript accumulation on most of the stress-related genes compared to the ‘Trincadeira’ cultivar in both production modes. Our study provides valuable insights into the effectiveness of PRIs and elicitors in increasing plant expression levels of stress-responsive genes, leading to greater resilience to pathogen attacks and emphasizing their position in organic agriculture.