Tea tree oil (TTO) and its two characteristic components (terpinen-4-ol and 1,8-cineole) have been shown to inhibit
Botrytis cinerea
growth. In this study, we conducted a transcriptome analysis to ...determine the effects of TTO and its characteristic components, alone and in combination, against
B
.
cinerea
. Most differentially expressed genes (DEGs) from
B
.
cinerea
cells treated with terpinen-4-ol participated in the biosynthesis of secondary metabolites, and the metabolism of amino acids, carbohydrates, and lipids. All treatments containing terpinen-4-ol potentially induced mitochondrial dysfunction and oxidative stress. These were further confirmed by the decreased activities of several enzymes (e.g., succinate dehydrogenase (SDH), malate dehydrogenase (MDH), α-ketoglutarate dehydrogenase (α-KGDH), isocitrate dehydrogenase (ICDH)), the increased activities of certain enzymes (e.g., catalase (CAT), peroxidase (POD), superoxide dismutase (SOD)), and increased content of hydrogen peroxide (H
2
O
2
). 1,8-Cineole mainly affected DEGs involved in genetic information processing, resulting in cell death. This study provides insight into the molecular mechanism of
B
.
cinerea
inhibition by TTO, and explains the synergistic effect of terpinen-4-ol and 1,8-cineole on
B
.
cinerea
.
► Tea tree oil (TTO) vapor treatment alleviated gray mold and soft rot in strawberries. ► TTO vapor treatment maintained a higher quality of freshness than untreated fruit in storage. ► Spore ...germination and mycelial growth of Botrytis cinerea and Rhizopus stolonifer were inhibited by TTO. ► TTO induced H2O2 levels and SOD, PAL, POD and β-1,3-glucanase activities in strawberries.
The purpose of this study was to investigate the effect of tee tree oil (TTO) against the main fungal disease in strawberries and a possible mechanism for the effects. TTO vapor exhibited a higher activity against spore germination and mycelial growth of Botrytis cinerea and Rhizopus stolonifer under in vitro conditions. TTO vapors at 0.9g/L significantly reduced artificially inoculated gray mold and soft rot in vivo, and treated strawberries maintained a fresher quality than untreated strawberries during storage. In addition, this treatment also enhanced the resistance of strawberries against B. cinerea, which caused a higher hydrogen peroxide (H2O2) level and activities of superoxide dismutase (SOD), phenylalanine ammonia-lyase (PAL), peroxidase (POD) and β-1,3-glucanase during the first period of incubation. These results indicate that TTO can reduce fruit decay, possibly by inhibiting pathogen growth directly and inducing disease resistance indirectly, and TTO vapor may provide an alternative means of controlling disease in strawberries.
•Chitosan combined with clove oil showed in vitro synergistic antifungal activity against P. digitatum.•The combined treatment caused alterations in P. digitatum hyphal morphology and disruption of ...cell membranes.•The combined coating did show synergistic effects with artificial green mold on mandarins.•A combined coating improved the activities of PAL and chitinase at the later stage of incubation.
The antifungal activity of chitosan combined with clove oil against Penicillium digitatum, the causal agent of citrus green mold, was tested in vitro and in vivo. Chitosan combined with clove oil inhibited mycelial growth more than individual treatments, which was related to the greater release of cellular material and the largest alterations in hyphal morphology of P. digitatum. However, compared to chitosan alone, 1% chitosan coatings combined with various amounts of clove oil (0.5, 1 or 2mL/L) showed no greater ability in controlling decay development on artificially inoculated citrus fruit. 1% chitosan combined with 0.5mL/L clove oil appeared to slightly reduce lesion diameter and enhanced the activities of defense enzymes, including chitinase and phenylalanine ammonia-lyase at the later stages of incubation. This study indicated that the synergistic antifungal activity of chitosan-clove oil observed in in vitro studies was not found in in vivo tests. Therefore, the data suggest that a coating of 1% chitosan alone, not combined with clove oil, can effectively contribute to the control of green mold on citrus fruit.
•Cooking methods affect the nutritional quality of red cabbage.•Fresh-cut red cabbage could retain the highest nutrition.•Steaming with less water and cooking time was recommended to use in Asian ...cuisine.
The aim of this work is to investigate the effects of domestic cooking methods, including steaming, microwave heating, boiling and stir-frying on the nutritional quality of red cabbage. Compared with fresh-cut red cabbage, all cooking methods were found to cause significant reduction in anthocyanin and total glucosinolates contents. Moreover, steaming resulted in significantly greater retention of vitamin C and DPPH radical-scavenging activity, while stir-frying and boiling, two popular Chinese cooking methods, led to significant losses of total phenolic, vitamin C, DPPH radical-scavenging activity, and total soluble sugar as well as reducing sugars. Normally, red cabbage consumed fresh in salads could maintain the highest nutrition. However, considering the habits of Asian cuisine, it is recommended to use less water and less cooking time, such as steaming based on our present results, so as to retain the optimum benefits of the health-promoting compounds.
Myrosinases are β-thioglucoside glucosidases that are unique to the Brassicales order. These enzymes hydrolyze glucosinolates to produce compounds that have direct antibiotic effects or that function ...as signaling molecules in the plant immune system, protecting plants from pathogens and insect pests. However, the effects of jasmonic acid (JA), a plant hormone that is crucial for plant disease resistance, on myrosinase activity remain unclear. Here, we systematically studied the effects of JA on myrosinase activity and explored the associated internal transcriptional regulation mechanisms. Exogenous application of JA significantly increased myrosinase activity, while the inhibition of endogenous JA biosynthesis and signaling reduced myrosinase activity. In addition, some myrosinase genes in Arabidopsis (Arabidopsis thaliana) were upregulated by JA. Further genetic and biochemical evidence showed that transcription factor FAMA interacted with a series of JASMONATE ZIM-DOMAIN proteins and affected JA-mediated myrosinase activity. However, among the JA-upregulated myrosinase genes, only THIOGLUCOSIDE GLUCOHYDROLASE 1 (TGG1) was positively regulated by FAMA. Further biochemical analysis showed that FAMA bound to the TGG1 promoter to directly mediate TGG1 expression in conjunction with Mediator complex subunit 8 (MED8). Together, our results provide evidence that JA acts as an important signal upstream of the FAMA/MED8-TGG1 pathway to positively regulate myrosinase activity in Arabidopsis.
Natural products extracted from plants are an alternative method for controlling postharvest citrus blue mold, caused by
Penicillium italicum
(
P. italicum
)
.
In this study, RNA sequence analysis ...was used to investigate the underlying anti-fungal mechanism of flavonoids from
Sedum aizoon
L. (FSAL) on
P. italicum
. Significant differences in 3592 genes were observed, including 2507 up-regulated and 1085 down-regulated genes between the FSAL-treated and the control groups. Furthermore, the GO and KEGG analysis results indicated that FSAL inhibited genes related to the integral components of membrane, oxidation–reduction process, mitochondrion, ribosome, and amino acid metabolism. In the presence of FSAL, the cellular constituents, including DNA and RNA were leaked from hyphae of
P. italicum
. Reactive oxygen species (ROS) production in
P. italicum
was also determined with a significant concentration-effect under the treatment of FSAL. Thus, we speculate that the inhibitory activity of FSAL on
P. italicum
is mainly achieved by damaging the structure of the cell membrane and cell wall, disrupting the process of mitochondrial respiratory metabolism, protein biosynthesis, and amino acid metabolism, leading to cell death. The present study provided a global perspective on the molecular mechanism of FSAL on
P. italicum
through transcriptome analysis, which may help develop a novel plant-derived anti-fungal agent for the blue mold of citrus.
Purpose
To present a novel MR pulse sequence and modeling algorithm to quantify the water exchange rate (kw) across the blood–brain barrier (BBB) without contrast, and to evaluate its clinical ...utility in a cohort of elderly subjects at risk of cerebral small vessel disease (SVD).
Methods
A diffusion preparation module with spoiling of non–Carr‐Purcell‐Meiboom‐Gill signals was integrated with pseudo‐continuous arterial spin labeling (pCASL) and 3D gradient and spin echo (GRASE) readout. The tissue/capillary fraction of the arterial spin labeling (ASL) signal was separated by appropriate diffusion weighting (b = 50 s/mm2). kw was quantified using a single‐pass approximation (SPA) model with total generalized variation (TGV) regularization. Nineteen elderly subjects were recruited and underwent 2 MRIs to evaluate the reproducibility of the proposed technique. Correlation analysis was performed between kw and vascular risk factors, Clinical Dementia Rating (CDR) scale, neurocognitive assessments, and white matter hyperintensity (WMH).
Results
The capillary/tissue fraction of ASL signal can be reliably differentiated with the diffusion weighting of b = 50 s/mm2, given ~100‐fold difference between the (pseudo‐)diffusion coefficients of the 2 compartments. Good reproducibility of kw measurements (intraclass correlation coefficient = 0.75) was achieved. Average kw was 105.0 ± 20.6, 109.6 ± 18.9, and 94.1 ± 19.6 min–1 for whole brain, gray and white matter. kw was increased by 28.2%/19.5% in subjects with diabetes/hypercholesterolemia. Significant correlations between kw and vascular risk factors, CDR, executive/memory function, and the Fazekas scale of WMH were observed.
Conclusion
A diffusion prepared 3D GRASE pCASL sequence with TGV regularized SPA modeling was proposed to measure BBB water permeability noninvasively with good reproducibility. kw may serve as an imaging marker of cerebral SVD and associated cognitive impairment.
Abstract
Sucrose metabolism, particularly the decomposition of sucrose by invertase, plays a central role in plant responses to cold stress. Invertase inhibitors (INHs) evolved in higher plants as ...essential regulators of sucrose metabolism. By limiting invertase activity, INHs keep cellular sugar levels elevated, which provides enhanced protection to plants under stress. Our results showed that the expression of
PpVIN2
, the only vacuolar invertase (VIN) gene in peach fruit sensitive to chilling temperatures, increases significantly during cold storage, while VIN enzyme activity increases more modestly. We also found that peach fruit transiently overexpressing
PpINH1
had decreased VIN activity. Interactions of PpINH1 and PpVIN2 with recombinant proteins were shown by yeast two-hybrid assays and bimolecular fluorescence complementation assays, as well as in vitro. During cold storage, trehalose-treated peach fruit had significantly increased
PpINH1
expression, decreased VIN enzyme activity, and significantly higher sucrose content than did untreated fruit. As a result, the treated fruit had enhanced resistance to chilling injury. Collectively, our data show that the post-translational repression of VIN enzyme activity by PpINH1 helps maintain sucrose levels in peach fruit during cold storage, thereby improving resistance to chilling injury.
We investigated the effects of at-harvest maturity of ‘YuLu’ peach fruit on soluble sugar metabolism and their relationship with chilling injury susceptibility. Peaches were sorted into four maturity ...groups at harvest by
I
AD
(index of the absorbance difference between 670 and 720 nm) then stored at 5 °C for 28 days. Fruit quality parameters, flesh browning index, malondialdehyde (MDA) content, soluble sugar content, gene expression, and enzyme activities associated with sucrose metabolism were measured. The more mature fruit groups had significantly (
p
< 0.05) lower firmness, higher soluble solid content, a* values of background color, sorbitol and sucrose content at harvest. During the cold storage, the higher flesh browning index in the mature groups (M3 and M4) maybe due to the double stress of senescence and chilling injury because there was concomitant sharp increase in MDA content. However, the most immature at-harvest group (M1) had the significantly (
p
< 0.05) higher MDA content after 14 days of cold storage, and a flesh browning index significantly (
p
< 0.05) higher than the M2 group (the next more mature group), late in the storage period. Moreover, the M1 group had lower sucrose content at postharvest and higher activities and transcript levels of sucrose degrading enzymes and lower levels of sucrose synthesis enzymes, which was responsible for the lower sucrose levels than M2 group during storage. It was concluded that the more immature peach fruit with lower sucrose content, have a higher chilling susceptibility than more mature fruit.
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