Terpinen-4-ol, the main component of tea tree oil, markedly increases the disease resistance of postharvest strawberry fruit. To understand the mechanism underlying the enhancement of disease resistance, a high-throughput RNA-seq was used to analyze gene transcription in terpinen-4-ol-treated and untreated fruit. The results show that terpinen-4-ol induces the expression of genes in the jasmonic acid (JA) biosynthesis pathway, secondary metabolic pathways such as phenylpropanoid biosynthesis, and pathways involved in plant-pathogen interactions. Terpinen-4-ol treatment reduced disease incidence and lesion diameter in strawberry fruit inoculated with Botrytis cinerea. Terpinen-4-ol treatment enhanced the expression of genes involved in JA synthesis (FaLOX, FaAOC, and FaOPR3) and signaling (FaCOI1), as well as genes related to disease defense (FaPAL, FaCHI, and FaGLU). In contrast, treatment with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM) accelerated disease development and inhibited the induction of gene expressions by terpinen-4-ol. We conclude that the JA pathway participates in the induction of disease resistance by terpinen-4-ol in strawberry fruit. More generally, the results illuminate the mechanisms by which disease resistance is enhanced by essential oils.
Greenhouse gases (GHGs) carbon dioxide (CO2) and nitrous oxide (N2O), contribute significantly to global warming, and they have increased substantially over the years. Reforestation is considered as an important forestry application for carbon sequestration and GHGs emission reduction, however, it remains unknown whether reforestation may instead produce too much CO2 and N2O contibuting to GHGs pollution. This study was performed to characterize and examine the CO2 and N2O emissions and their controlling factors in different species and types of pure and mixture forest used for reforestation. Five soil layers from pure forest Platycladus orientalis (PO), Robinia pseudoacacia (RP), and their mixed forest P-R in the Taihang mountains of central China were sampled and incubated aerobically for 11 days. The P-R soil showed lower CO2 and N2O production potentials than those of the PO soils (P
Chinese bayberry fruit were treated with hot air (HA) at 48 ℃ for 3 h and then stored at 4 ℃ for 15 d. Changes in fungal communities were analyzed by high-throughput sequencing (HTS), and decay and fruit quality were monitored during storage. The results showed that HA treatment effectively maintains fruit quality and the richness and diversity of fungal communities. Heat treatment inhibited decay development and reduced the growth of fungi in the genera Botryotinia spp., Davidiella spp., Hanseniaspora spp., and Candida spp. Canonical correspondence analysis further revealed that Botryotinia spp. and Davidiella spp. were positively correlated with fruit decay and weight loss. FUNGuild analysis demonstrated that HA-treated bayberries had a lower relative abundance within the plant pathogen guild, but higher relative abundance within the endophyte guild. The results suggest that HA treatment reduces pathogens by favoring the increase of endophytes, providing new insight into the decay development and quality changes during the storage of postharvest Chinese bayberries.
Thinned peach polyphenols (TPPs) were extracted by ultrasonic disruption and purified using macroporous resin. Optimized extraction conditions resulted in a TPPs yield of 1.59 ± 0.02 mg GAE/g FW, and optimized purification conditions resulted in a purity of 43.86% with NKA-9 resin. TPPs composition was analyzed by UPLC-ESI-QTOF-MS/MS; chlorogenic acid, catechin, and neochlorogenic acid were the most abundant compounds in thinned peaches. Purified TPPs exhibited scavenging activity on DPPH, ABTS, hydroxyl radical, and FRAP. TPPs inhibited α-amylase and α-glucosidase by competitive and noncompetitive reversible inhibition, respectively. TPPs also exhibited a higher binding capacity for bile acids than cholestyramine. In summary, TPPs from thinned peaches are potentially valuable because of their high antioxidant, hypoglycemic, and hypolipidemic capacities, and present a new incentive for the comprehensive utilization of thinned peach fruit.