Hardy kiwifruits (Actinidia arguta) were treated with 20 μl/l 1-methylcyclopropene (1-MCP) for 16 h at 10 °C and subsequently stored at 1 ± 0.5 °C. Anticancer properties of the fruit extracts were tested against five different human cancer cells. The hardy kiwifruits, without 1-MCP treatment, showed increases in both respiration and ethylene production rates during fruit storage. The 1-MCP treatment remarkably inhibited fruit ripening by reducing respiration and ethylene production. Fruits with the 1-MCP treatment could be stored for up to 5 weeks by maintaining higher fruit firmness, ascorbic acid and total phenolic contents compared to the control. The hardy kiwifruit extracts showed anti-proliferative effects to Hep3B and HeLa cells but not to HT29, HepG2 and LoVo cells. These results suggest that the application of 1-MCP at harvest effectively delayed the ripening process of the fruits, and the fruit extract had beneficial effects for the prevention of human cancer growth.

We applied exogenous ethylene to 'Jecy green' kiwifruit to elucidate the differences in fruit quality and metabolite profiling between naturally ripe (NR) and ethylene-induced ripe (ER) kiwifruit. Kiwifruit were exposed to ethylene (200μL/L) for 12h at 20°C and maintained for 9days at 20°C. Two metabolites of ascorbic acid and arabinose significantly decreased during kiwifruit ripening regardless of the ripening method. The concentrations of sucrose, myo-inositol, citric acid, and malic acid in NR fruit were substantially higher than those in ER fruit, while the concentrations of fructose, glucose, and quinic acid in ER fruit were higher than those in NR fruit. NR and ER kiwifruit were statistically similar in regard to overall sensory profile, even though the metabolite profiling showed a little difference. The application of ethylene to 'Jecy green' kiwifruit to regulate ripening for commercial purposes can result in good quality fruit without side effects.

The contents of eight phytohormones and the expression levels of genes encoding enzymes related to abscisic acid (ABA) biosynthesis and deactivation/degradation and transcription factors (TFs) related to fruit ripening were studied in the non-climacteric strawberry fruit (Fragaria × ananassa Duch., cv. 'Seolhyang') at six developmental stages. The hormones tested were ABA, indole-3-acetic acid (IAA), gibberellic acid 4 (GA4), jasmonic acid (JA), methyljasmonate (MJ), jasmonoyl isoleucine (JA-Ile), salicylic acid (SA), and ethylene (ET). The developmental and ripening stages studied were small green (S1, 11 days post-anthesis, DPA), green (S2, 20 DPA), breaker (S3, 24 DPA), pink (S4, 27 DPA), red (S5, 31 DPA), and fully red (S6, 40 DPA). IAA and GA4 contents were highest at S1 and gradually decreased after this stage. ABA content was low at S1-S3 and then increased rapidly until peaking at S6. By contrast, MJ content showed no significant changes over time, while SA content gradually increased. JA, JA-Ile, and ET contents were either insufficient for quantification or undetectable. Expression of the ABA biosynthesis genes FaNCED1 and FaABA2 increased during fruit ripening, whereas expression of the ABA deactivation/degradation genes FaUGT75C1 and FaCYP707A1 was high early in development, when ABA content was low, and then decreased. Among four ripening-related TF genes, FaMYB1, FaMYB5, FaMYB10, and FaASR, only the expression of FaMYB10 seemed to be closely related to strawberry fruit ripening. Our study supports the idea that ABA and FaMYB10 appear to be the key hormone and TF regulating strawberry ripening.