The peach industry faces serious economic losses because of the short “green” life of the fruit at postharvest. In the present study, we investigated the effects of putrescine (PUT) application on the quality characteristics, pattern of ripening, storage behavior, and shelf life of peach fruit during low-temperature storage. The aqueous solution of PUT (0, 1, 2, and 3 mM) was applied onto the peach trees at three distinctive stages of fruit growth and development. The fruit, harvested at the commercial stage of maturity, were stored at 1 ± 1 °C and 90 ± 2% relative humidity for 6 weeks. The data for fruit firmness, total soluble solids (SSC), titratable acidity (TA), ascorbic acid (AsA) content, rate of ethylene production, chilling injury (CI) index, and color perception were collected at harvest and then on a weekly basis throughout the storage period. The results showed that spray application of PUT significantly reduced the incidence of CI and reduced the rates of fruit softening, loss in fruit weight, SSC, TA, AsA content, and fading of skin color during storage, regardless of the doses of PUT applied or time of application. However, the positive effects on the quality characteristics of peach fruit, including CI, were more pronounced with the higher doses of PUT, specifically when applied at 2 mM. In conclusion, CI in peach fruit may be substantially alleviated by the spray application of 1–3 mM PUT during fruit growth without compromising the quality of the fruit for up to 6 weeks of low-temperature storage.

Scarcity of water is one of the most serious concerns in plant biology with diverse implications at all the levels of molecular, biochemical, and physiological phenomena of plant growth, development, and consequently the productivity. Most of the strategies to induce or enhance drought tolerance in plants are unreasonably expensive and/or time-consuming. Some studies conducted in the recent past have shown that plant growth regulators (PGRs) may induce/improve physiological tolerance in plants to cope with adverse environmental conditions including drought. The present study was aimed at investigating the effects of foliar spray of GABA (0, 1, 2, and 4 mM) applied 20 days following the germination of seeds, on vegetative growth, morphological characteristics, integrity of cell-membrane, and the levels of photosynthetic pigments and enzymatic antioxidants in carrot cvs. Supertaj and Bharat, grown under 100% and 50% field capacity of soil moisture. The treated and untreated (control) carrot plants were harvested and analyzed 2 weeks following the GABA application. The results revealed that foliar application of GABA improved the vegetative growth and significantly increased the levels of free amino acids, plastid pigments, enzymatic antioxidants, and the relative water content in the root crop grown under 50% field capacity of soil moisture, compared to control. Additionally, the GABA application decreased the electrolyte leakage of ions and melondialdehyde (MDA) content in carrot leaves. The carrots harvested from GABA-treated or untreated (control) plants were not significantly different for their protein contents. In conclusion, the incorporation of GABA in the production management of carrots may help plants to mitigate the adverse effects of water deficit stress.