•Single factor experiments approach was used for optimizing phenolics extraction from peach.•Several extracting parameters were studied: effect of solvent, time and temperature.•The optimal ...extraction conditions were determined.•Good correlations existed between antioxidant activities and TPC.•This is the first report on optimizing phenolic compounds extraction from peach fruit.
The aim of the present study is to investigate the effects of solvent type (ethanol, methanol, acetone and water), acetone concentration (20–100%, v/v), solvent acidity (0–2N), time (30–450min) and temperature (25–70°C) on the extraction of total phenolic compounds (TPC), total flavonoid compounds (TFC) and on the antioxidant capacity: 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity (DPPH-RSA) and ferric reducing power (FRP) of peach fruit (Prunus persica L.) using single factor experiments approach. All the studied extracting conditions showed significant effect (p<0.05) on TPC, TFC, DPPH-RSA and FRP. On the basis of TPC and antioxidant activity parameters, the best extraction conditions were 60% acetone without acidification for 180min at 25°C. Based on these optimized conditions, high content of TPC, DPPH-RSA and FRP of peach extracts were obtained with values of 363 GAE/100g, 48% percentage of inhibition and 317 AAE/100g, respectively. Good, positive or negative, Pearson correlation coefficients were found between TPC, TFC DPPH-RSA and FRP of peach extracts, especially under the influence of solvent type, solvent concentration and acidity extraction conditions.
Anthocyanin pigmentation is an important consumer trait in peach (Prunus persica). In this study, the genetic basis of the blood‐flesh trait was investigated using the cultivar Dahongpao, which shows ...high levels of cyanidin‐3‐glucoside in the mesocarp. Elevation of anthocyanin levels in the flesh was correlated with the expression of an R2R3 MYB transcription factor, PpMYB10.1. However, PpMYB10.1 did not co‐segregate with the blood‐flesh trait. The blood‐flesh trait was mapped to a 200‐kb interval on peach linkage group (LG) 5. Within this interval, a gene encoding a NAC domain transcription factor (TF) was found to be highly up‐regulated in blood‐fleshed peaches when compared with non‐red‐fleshed peaches. This NAC TF, designated BLOOD (BL), acts as a heterodimer with PpNAC1 which shows high levels of expression in fruit at late developmental stages. We show that the heterodimer of BL and PpNAC1 can activate the transcription of PpMYB10.1, resulting in anthocyanin pigmentation in tobacco. Furthermore, silencing the BL gene reduces anthocyanin pigmentation in blood‐fleshed peaches. The transactivation activity of the BL‐PpNAC1 heterodimer is repressed by a SQUAMOSA promoter‐binding protein‐like TF, PpSPL1. Low levels of PpMYB10.1 expression in fruit at early developmental stages is probably attributable to lower levels of expression of PpNAC1 plus the presence of high levels of repressors such as PpSPL1. We present a mechanism whereby BL is the key gene for the blood‐flesh trait in peach via its activation of PpMYB10.1 in maturing fruit. Partner TFs such as basic helix–loop‐helix proteins and NAC1 are required, as is the removal of transcriptional repressors.
•10 μM of MeJA effectively inhibited soft rot caused by R. stolonifer.•MeJA elevated the expression of JA biosynthetic and PR genes.•MeJA induced disease resistance against R. stolonifer by priming ...of defense responses.•PpWRKY45 activated defense-related gene expression by bind to their promoters.•PpWRKY45 is involved in MeJA-primed defense by enhancing defense-related gene expression.
Methyl jasmonate (MeJA) and WRKY transcription factors (TFs) are documented to exert vital defensive functions. Research concerning WRKY TFs together with MeJA-primed defense against Rhizopus stolonifer in peach fruit is still in its infancy. In the present study, the mode of MeJA on inducing resistance against soft rot caused by Rhizopus stolonifer in peaches during the postharvest storage and the involvement of WRKY TFs were investigated, and the results manifested that MeJA at 10 μM significantly reduced disease occurrence and lesion diameter after R. stolonifer infection during 60 h of storage at 20 °C. Moreover, the MeJA treatment promoted the activity of CHI and GLU and elevated the expression levels of PpLOX, PpAOS and PpOPR3. More importantly, the expression of PpCHI, PpGLU, PpPR-like, PpLOX, PpAOS and PpOPR3 were substantially and rapidly elevated in the peach fruit that pretreated with MeJA and inoculated with R.stolonifer, indicating that MeJA stimulated a specific priming defense against Rhizopus rot in peaches. Furthermore, a MeJA-related transcription factor PpWRKY45 was identified and characterized as a nucleus-localized protein that could activate the expression of PpCHI, PpGLU, PpPR-like, PpLOX, PpAOS and PpOPR3 by binding to W-box elements in their promoters. These results indicate that PpWRKY45 is involved in MeJA-primed defense against R. stolonifer by activating JA biosynthetic and PR genes of peach fruit.
Peaches are a promising option for the Florida agricultural industry with plenty of revenue streams including fresh market, U-pick, and retail sales, as well as alternatives in the juicing and ...fermentation industries. This publication discusses a 2018 case study completed on a Florida peach cultivar. ‘UFSun’ were harvested, processed into juice, and analyzed for sugar content, juice yield, and general economic feasibility. UF/IFAS has bred peach cultivars that grow commercially in tropical and subtropical climates such as Florida’s and are harvest-ready two months before the rest of the United States, offering competitive advantages. Unfortunately, their small size renders them less profitable in fresh markets compared to larger non-Florida cultivars. Knowing the processing characteristics of Florida peaches provides valuable information for peach farmers who are considering using their peaches for juicing, fermentation, and similar purposes.
•MeJA primed the expression of PpWRKY70 and accumulation of phenolic compounds.•MeJA enhanced the enzyme activity and encoding gene expression of PAL and 4CL.•PpWRKY70 activated PpPAL and Pp4CL ...transcription via binding to their promoters.•PpWRKY70 is involved in MeJA-primed defense by activating phenylpropanoid pathway.
The molecular mechanisms underlying methyl jasmonate (MeJA) primed defense against Rhizopus stolonifer through regulating phenylpropanoid pathway in peaches and the involvement of WRKY transcription factor were investigated. MeJA treatment enhanced the activity of phenylalanine ammonia-lyase (PAL) and 4-coumarate-CoA ligase (4CL), and promoted the accumulation of total phenolics, total flavonoids and lignin content as well as the main individual phenolic compounds, including chlorogenic acid, neochlorogenic acid and epicatechin. Moreover, transcripts of PpPAL and Pp4CL transcription were substantially and rapidly enhanced upon inoculation with the pathogen in MeJA-treated fruit, indicating that MeJA triggered a priming defense via enhancing phenylpropanoid pathway in peaches. Furthermore, MeJA primed the expression of PpWRKY70, which was identified as a transcription activator of PpPAL and Pp4CL via binding to their W-boxes. Taken together, our results demonstrate that PpWRKY70 is involved in the MeJA-primed defense by activating the phenylpropanoid pathway.
Low-chill peach trees growing under Florida conditions can become vigorous and large. Summer pruning is a management strategy that can be applied to help restructure the canopy, direct the tree’s ...resources into fruit production, and improve the efficiency of fieldwork. Without summer pruning, peach orchards in subtropical regions will continue to grow vigorously and, if left unmanaged, will reach a point at which ladders will be required to harvest and maintain the trees. Summer pruning can be a means of reducing overall tree size, redistributing fruiting wood for easier harvesting, reducing disease pressure, and increasing fruit quality. This new 5-page publication of the UF/IFAS Horticultural Sciences Department, written by Ali Sarkhosh, Dustin Huff, Trequan McGee, and Juanita Popenoe, provides an illustrated step-by-step guide to summer pruning of peach trees.https://edis.ifas.ufl.edu/hs1377
Abstract
To date, about two dozen low-mass embedded protostars exhibit rich spectra with lines of complex organic molecules (COMs). These protostars seem to possess a different enrichment in COMs. ...However, the statistics of COM abundance in low-mass protostars are limited by the scarcity of observations. This study introduces the Perseus ALMA Chemistry Survey (PEACHES), which aims at unbiasedly characterizing the chemistry of COMs toward the embedded (Class 0/I) protostars in the Perseus molecular cloud. Of the 50 embedded protostars surveyed, 58% of them have emission from COMs. 56%, 32%, and 40% of the protostars have CH
3
OH, CH
3
OCHO, and N-bearing COMs, respectively. The detectability of COMs depends neither on the averaged continuum brightness temperature, a proxy of the H
2
column density, nor on the bolometric luminosity and the bolometric temperature. For the protostars with detected COMs, CH
3
OH has a tight correlation with CH
3
CN, spanning more than two orders of magnitude in column densities normalized by the continuum brightness temperature, suggesting a chemical relation between CH
3
OH and CH
3
CN and a large chemical diversity in the PEACHES samples at the same time. A similar trend with more scatter is also found between all identified COMs, which hints at a common chemistry for the sources with COMs. The correlation between COMs is insensitive to the protostellar properties, such as the bolometric luminosity and the bolometric temperature. The abundance of larger COMs (CH
3
OCHO and CH
3
OCH
3
) relative to that of smaller COMs (CH
3
OH and CH
3
CN) increases with the inferred gas column density, hinting at an efficient production of complex species in denser envelopes.
Peach are susceptible to chilling injury (CI) when stored at a low temperature and the postharvest application of methyl jasmonate (MeJA) is well known to alleviate CI in peach fruit. However, the ...optimal dose for the treatment of MeJA is still debated in peaches and the underlying mechanism remains largely unknown. In this study, we screened the optimal concentration of MeJA treatment in stony hard and melting flesh peaches, then investigated the involvement of α-linolenic acid metabolism and jasmonate acid (JA) signaling pathway in the MeJA-induced chilling tolerance. The results showed that 10 mol L−1 was the broad-spectrum concentration of MeJA treatment for CI alleviation in the two peach cultivars. Also, MeJA treatment improved the degree of fatty acid unsaturation in cell membrane by delaying the decrease in unsaturated fatty acids (USFAs) and the increase in saturated fatty acids (SFAs), resulting in the activation of α-linolenic acid metabolism. Correspondingly, it maintained a higher concentration of α-linolenic acid and higher activities of lipoxygenase (LOX), allene oxide synthase (AOS) and allene oxide cyclase (AOC). It also induced the expressions of PpLOX, PpAOS, PpAOC, PpACOX and PpFadA in peaches during the end of the cold storage at 5 °C and the shelf-life at 20 ℃. Meanwhile, the increased α-linolenic acid metabolism in MeJA treated fruit led to accumulations in JA and jasmonic acid isoleucine (JA-Ile), which boosted the JA signaling pathway by up-regulating the expressions of PpCOI1, PpJAZ and PpMYC2. Thus, it was suggested that MeJA treatment activated α-linolenic acid metabolism and JA signaling pathway might be contributing to alleviating CI in peaches during cold storage.
•10 mol L−1 MeJA had better effect on CI alleviation in the two peach cultivars.•MeJA improved the unsaturation in cell membrane via improving USFAs/SFAs ratio.•MeJA activated α-linolenic acid metabolism at enzymatic and transcript levels.•MeJA boosted the JA signaling pathway by up-regulating PpJAZ and PpMYC2.
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•CETH treatment alleviated chilling injury in peach fruit.•CETH promoted total phenolic content whereas inhibited POD activity.•CETH induced the accumulation of phospholipids, PC and ...PE.•CETH induced the accumulation of Cer and its derivatives, e.g. CerG3 and CerP.•CETH led a lipid remodeling to facilitate membrane stability.
Horticultural products, including peaches, are susceptible to chilling injury (CI), on which the effect of ethylene is still controversial, and the underlying mechanism remains elusive. Here, changes in biochemical and molecular mechanisms involved in phenolic and lipid metabolism were compared between stony hard peaches with continuous ethylene (CETH) and controls. CETH effectively compromised internal browning incidence, accompanied by the inhibited activity of peroxidase but enhanced phenolic content, and less membrane leakage with reduced H2O2 and malondialdehyde contents. Intriguingly, CETH elevated levels of phospholipids and unsaturation of their acyl chains, coincident with the lower transcript levels of phospholipase Dα1 but higher fatty acid desaturase2/8.1, and the enhanced sphingolipid contents and biosynthesis concomitant with higher transcript levels of glucosylceramide synthase but lower inositol phosphorylceramide synthase3. Therefore, CETH can ameliorate fruit CI through adjusting phenolic and lipid metabolism, especially comprehensive remodeling of phospholipids and sphingolipids to contribute to the membrane stability.
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