Transforming stressed plants into healthy foods.

This paper presents the current status of transforming stressed plants into healthy foods and the future trends in this emerging field. Herein, we describe the three major key elements to advance this field, including a better understanding of the mode of action of oxidative stress on nutraceutical biosynthesis under pre- and postharvest scenarios either converting plants into biofactories of nutraceuticals or creating 'functional fresh produce' while preserving quality. We discuss the need of designing healthy products based on stressed fresh produce and by-products and present a pragmatic strategy to enhance nutraceuticals in plants, and finally we propose designing appropriate studies with stressed plants targeting immunomodulatory properties to determine preventive and therapeutic effects against chronic diseases and the appropriate recommended dose.

Is pomegranate husk scald during storage induced by water loss and mediated by ABA signaling?

BACKGROUND: Husk scald (HS) is a physiological disorder limiting the marketability of pomegranate fruit during long-term storage. Herein we propose that HS is triggered by water loss and mediated by ABA signaling. Therefore, pomegranate fruit were stored at three different storage temperatures (3.5, 7 and 11°C) and 96.5% ± 2.3% relative humidity (RH) evaluating weight loss (WL), abscisic acid (ABA), respiration rate (RR), total phenolics (TP), total anthocyanin (TA), antioxidant activity (AA), exocarp electrolyte leakage (EL), malondialdehyde (MDA), color attributes, browning index and visual quality of fruit. RESULTS: HS appeared after 3 months of storage at 11 °C, less at 7°C and non-present at 3.5°C. Incidence of HS occurred along with higher WL, RR, EL, MDA, and ABA content. Conversely, TP, TA and AA decreased significantly. WL increased with water vapor pressure deficit (VPD) at higher temperatures. After 93 days, 11 °C fruit reached ~10% WL while ABA increased to ~150 µg kg-1 . However, 3.5 and 7 °C fruit, reached 5 and 7% WL while ABA was ~31 and 75 µg kg-1 , respectively. CONCLUSION: Herein, we propose a mechanistic model of HS development where water stress induces ABA as a primary signaling molecule that triggers the HS response mediated by reactive oxygen species (ROS). Accumulation of ROS induces phenolic biosynthesis and oxidative stress promotes loss of membrane compartmentalization that induces phenolic degradation. Ultimately, husk scalding becomes visible due to the oxidation of phenolics into brown pigments. © 2022 Society of Chemical Industry.