Physiochemical properties of petunia edible flowers grown under saline conditions and their postharvest performance under modified atmosphere packaging and ethanol application

Morphological, physiological, and secondary metabolic responses of Taraxacum officinale to salt stress

Salt stress has a major effect on growth and secondary metabolism in medicinal plants, however, the effect of salt stress on Taraxacum officinale F. H. Wigg. is still scarce. In this study, we evaluated the effects of salt stress on the physiology, morphology, phenolic acid accumulation, and expression of genes involved in phenolic acid biosynthesis in T. officinale. We found that plants grew well at 1 g kg^-1 NaCl, and the state of photosystem Ⅱ (PSⅡ) and the organization of the chloroplasts at 0.5 g kg^-1 NaCl showed no significant differences compared with the control. However, 2 g kg^-1 and 4 g kg^-1 NaCl inhibited growth and accelerated leaf senescence. At 4 g kg^-1 NaCl, the fresh and dry weights decreased to 28% and 42% of the control, while chlorosis and necrosis were observed on the leaves. Furthermore, up-regulation of the expression of ToC3'H corresponded with an increase in the levels of caffeoylquinic acids (chlorogenic acid and isochlorogenic acid A) at NaCl concentration ≤ 1 g kg^-1. Expressions of four phenolic acid biosynthesis genes, ToC4H, To4CL, ToHCT, and ToHQT, were down-regulated with increasing NaCl concentrations, consistent with the observed decreases in caftaric and cichoric acids. In summary, cultivation of T. officinale under mild salt stress (NaCl ≤ 1 g kg^-1) is feasible and facilitates the accumulation of caffeoylquinic acids; thus this species may be recommended for saline soils.

A Combination of Melatonin and Ethanol Treatment Improves Postharvest Quality in Bitter Melon Fruit

Central composite design (CCD), utilized with three independent variables, verified that the optimal treatment conditions in bitter melon fruit were melatonin (MT) concentration of 120 µmol L−1, ethanol concentration of 6%, and immersing time of 10 min. Under optimal conditions, the experimental values of firmness, chilling injury (CI) index, and weight loss were shown as 27.81 N, 65.625%, and 0.815%, respectively. Moreover, the combined effect of MT and ethanol on CI and physiological quality in postharvest bitter melon fruit stored at 4 °C was investigated. It was found that the combined treatment contributed to the reduced CI symptoms and inhibited ion leakage and malondialdehyde (MDA) accumulation. Moreover, higher levels of chlorophyll, total soluble solids (TSSs), soluble sugar, soluble protein, and ascorbic acid (AsA) were observed in comparison with the control group. Furthermore, the synthesis of total phenols and flavonoids in bitter melon was greatly promoted. Therefore, the combination of MT and ethanol could have the potential for alleviating CI and maintaining postharvest quality for the duration of cold storage.