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Plants subjected to stress need to respond rapidly and efficiently to acclimatize and survive. In this paper, we investigated a selected gene set potentially involved in early cell reprogramming in two rice genotypes with contrasting salinity tolerance (Pokkali tolerant and IR29 susceptible) in order to advance knowledge of early molecular mechanisms of rice in dealing with salt stress. Selected genes were evaluated in available transcriptomic data over a short period of 24 h and involved enzymes that avoid ROS formation (AOX, UCP and PTOX), impact ATP production (PFK, ADH and COX) or relate to the antioxidant system. Higher transcript accumulation of AOX (ROS balancing), PFK and ADH (alcohol fermentation) was detected in the tolerant genotype, while the sensitive genotype revealed higher UCP and PTOX transcript levels, indicating a predominant role for early transcription of AOX and fermentation in conferring salt stress tolerance to rice. Antioxidant gene analyses supported higher oxidative stress in IR29, with transcript increases of cytosolic CAT and SOD from all cell compartments (cytoplasm, peroxisome, chloroplast and mitochondria). In contrast, Pokkali increased mRNA levels from the AsA-GSH cycle as cytosolic/mitochondrial DHAR was involved in ascorbate recovery. In addition, these responses occurred from 2 h in IR29 and 10 h in Pokkali, indicating early but ineffective antioxidant activity in the susceptible genotype. Overall, our data suggest that AOX and ADH can play a critical role during early cell reprogramming for improving salt stress tolerance by efficiently controlling ROS formation in mitochondria. We discuss our results in relation to gene engineering and editing approaches to develop salinity-tolerant crops.

Phytochemicals from tropical fruits and their by-products have shown the potential to use as antimicrobial natural. This study aimed to optimize the recovery of phenolic compounds (total polyphenols and flavonoids) from cashew apple using ultrasound-assisted extraction to promote the functional attributes to its coproducts and to evaluate their antioxidant and antimicrobial potential. An experimental design applying a response surface methodology was used for the extraction process. The ethanol concentration (13.76 % to 56.21 %) and the ultrasonic bath time (21.71 to 78.28 min.) were considered as independent variables, and the polyphenols content, total flavonoids as dependent variables. The phenolic profile of optimized hydroalcoholic extracts (UPLC-QToF-MSE) and their antimicrobial potential against foodborne pathogenic bacteria was assessed. The optimized conditions for a total phenolic extract of 750 mg GAE 100 g-1 were 42.16 % ethanol and 37.34 min in an ultrasonic bath, and for total flavonoids of 479.07 mg of quercetin per 100 g-1 were 37.15 % ethanol and 25.13 min. A total of 15 compounds including quercetin and myricetin derivatives, gallic acid, and anacardic acid were identified. The extracts displayed effective action against Staphylococcus aureus and Listeria monocytogenes. The extracts were effective against foodborne pathogenic bacteria thus demonstrating their potential to be a good natural alternative to synthetic additives in the food industry.