It’s not easy being green: Maintaining broccoli postharvest quality

Up to 40% of harvested broccoli never reaches consumers due to quality losses during senescence, including yellowing and nutrient degradation. Reactive oxygen species cause oxidative stress within the plant, accelerating these negative changes through the jasmonate (JA) pathway.  Gage et al.  investigated if oxidative hormesis, where a mild activation of the stress-response pathway improves the plants’ ability to tolerate subsequent extreme stress, could help maintain the quality of Tenderstem® broccoli during postharvest storage. Despite success in other broccoli varieties, treatment with hydrogen peroxide did not maintain quality, and methyl JA exacerbated yellowing. This study also found that in Tenderstem®, early yellowing is due to carotenoid accumulation rather than chlorophyll degradation, differing from previous observations in other broccoli varieties. The authors suggest that the later developmental stage of Tenderstem® at harvest, along with genotypic differences, contributes to the altered response. In addition, this study also demonstrated that lower storage temperatures (5 vs. 10 °C) reduced JA-pathway gene expression, effectively prolonging green colour retention for over eight days. While chilling is energy-intensive, reducing food loss carries environmental and economic benefits, making it a worthwhile tradeoff. Overall, this study highlights the importance of understanding the diversity in stress responses and developmental differences between crop varieties, which impact postharvest strategies to minimize food losses. (Summary by Ciara O’Brien @ciara.obrien.bsky.social) Journal of Horticultural Science and Biotechnology 10.1080/14620316.2024.2449032