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A water-soluble polysaccharide WSP1 was extracted from the fruiting body of Termitornyces albuminosus. Its molecular weight, monosaccharide composition and molecular structure were determined by GPC, GC–MS, UV spectroscopy, FT-IR spectroscopy, methylation analysis, NMR (1D and 2D) and AFM. Moreover, the antioxidant activity of WSP1 was evaluated in vitro by the tests of reducing power, scavenging ability on DPPH radical and hydroxyl radical, and chelating ability on ferrous ion. The results indicated that the molecular weight of WSP1 was 9 kDa, and it was mainly composed of fucose and galactose in a molar ratio of 1:3.09. Based on monosaccharide composition, methylation analysis and NMR, the possible repeating unit of WSP1 was presented as follows: →2-α- l -Fucp-1→ (6-α- d -Galp-1)3→. The antioxidant assay revealed that, in the concentration range tested in this experiment, WSP1 had strong scavenging ability on DPPH radical, suggesting that WSP1 could be potentially used as a powerful radical scavenger.

The phytohormone auxin has been proved to be involved in the regulation of quality traits in climacteric fruit ripening, but there was little information about the correlation between auxin and aroma volatiles in fruit. In the present study, the effect of auxin on aroma volatiles in tomato fruit during postharvest ripening was studied by treating detached tomato fruit at mature green stage with 2, 4-dichlorophenoxyacetic acid. The results showed that exogenous auxin delayed the ripening process of tomato fruit via inhibiting the ethylene production and the carotenoids accumulation, as well as the degradation of chlorophyll. In addition, exogenous auxin enhanced the accumulation of phenolic volatiles such as phenylacetaldehyde (1.57-fold), 2-phenylethanol (1.56-fold) and methyl benzoate (1.75-fold), and inhibited the production of 1-hexanol (56.59 %), 1-nitro-2-phenylethane (23.74 %), benzyl cyanide (45.69 %) and 2-isobutylthiazole (35.18 %). Exogenous auxin altered the expression of a number of key genes involved in the biosynthetic pathway of aroma volatiles, including induction of SlSAMT1, LePAR1and LePAR2, and inhibition of TomloxC, HPL, ADH2, LeCCD1s, LePAR1, LePAR2, LeAADCs, SlBCAT1. The log2 fold change of these genes ranged between -4.53 and 3.02 compared to that in the control group. Moreover, correlation analysis revealed that changes of apocarotenoids and amino acid-derived volatiles were positively correlated with the expressions of related genes in response to auxin. The present study provided valuable information for further elucidating the regulation of tomato fruit aroma as well as quality traits during ripening.

Abscisic acid (ABA) is a phytohormone which is involved in the regulation of tomato ripening. In this research, the effects of exogenous ABA on the bioactive components and antioxidant capacity of the tomato during postharvest ripening were evaluated. Mature green cherry tomatoes were infiltrated with either ABA (1.0 mM) or deionized water (control) and stored in the dark for 15 days at 20 &deg, C with 90% relative humidity. Fruit colour, firmness, total phenolic and flavonoid contents, phenolic compounds, lycopene, ascorbic acid, enzymatic activities, and antioxidant capacity, as well as the expression of major genes related to phenolic compounds, were periodically monitored. The results revealed that exogenous ABA accelerated the accumulations of total phenolic and flavonoid contents, mostly increased the contents of detected phenolic compounds, enhanced FRAP and DPPH activity, and promoted the activities of PAL, POD, PPO, CAT, and APX during tomato ripening. Meanwhile, the expressions of the major genes (PAL1, C4H, 4CL2, CHS2, F3H, and FLS) involved in the phenylpropanoid pathway were up-regulated (1.13- to 26.95-fold) in the tomato during the first seven days after treatment. These findings indicated that ABA promoted the accumulation of bioactive components and the antioxidant capacity via the regulation of gene expression during tomato ripening.

Methyl jasmonate (MeJA) acts as an elicitor to stimulate phenolic compounds in fruit and vegetables. To explore the regulation of MeJA on phenolic compounds biosynthesis during postharvest tomato ripening, mature green tomato fruit were treated by 0.5 mM MeJA or deionized water under vacuum, and then kept in darkness for 16 d. Total phenolics and total flavonoids contents, phenolic compounds contents, enzymatic activities, as well as expression levels of genes in response to phenylpropanoid pathway were determined in the present study. Results showed exogenous MeJA enhanced total phenolics and flavonoids contents, augmented the contents of most phenolic compounds, as well as promoted enzymatic activities associated with phenylpropanoid pathway (PAL, C4H, 4CL, CHS, and CHI) during tomato ripening. Furthermore, MeJA up-regulated the expressions of the corresponding genes (1.16- to 19.32-fold) involved in phenylpropanoid pathway during the first 7 d. Results suggested MeJA enhanced phenolic compounds biosynthesis during postharvest tomato ripening via influencing the enzymatic activities and gene expressions. These results may provide valuable information for exploring technical means for the regulation of phenylpropanoid pathway during tomato ripening.

Many studies have shown that abscisic acid (ABA) regulates climacteric fruits ripening by inducing ethylene production. Nevertheless, the key components involved in the crosstalk between these two phytohormones in controlling fruit ripening remain unknown. SlAREB1, a downstream transcription factor in ABA signaling pathway, has been reported to mediate ABA signaling that regulates tomato ripening through induction of ethylene biosynthetic genes. NOR, a member of NAC domain family, was proved to act upstream of ethylene and essential for ripening- and ethylene-associated genes expression. Here, we found that the expression of SlAREB1 and NOR are both ABA-inducible, and SlAREB1 transcription reaches the peak level prior to NOR during the ripening process. Yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA) and dual luciferase assay indicated NOR as a novel direct target of SlAREB1. Transient over-expression of SlAREB1 in tomato fruits results in elevated expression of NOR as well as a number of downstream ethylene biosynthetic genes including SlACS2, SlACS4 and SlACO1, suggesting that SlAREB1 can mediate ABA signal to activate NOR transcription and ultimately promote ethylene synthesis. Based on these data, we present a model suggesting that the SlAREB1-NOR regulation is a crucial node modulating ABA-regulated ethylene biosynthesis during tomato fruit ripening.

In order to investigate the synergistic effect of abscisic acid and ethylene on tomato color development during ripening, mature green tomato fruit were harvested and treated with abscisic acid (ABA), 1-methylcyclopropene (1-MCP), alone or in combination, and dihydroguaiaretic acid (NDGA), and then were stored at 20 °C and 90% RH for fourteen days. Endogenous ethylene production, color development and the expression profiles of major related genes in treated fruits were examined. Furthermore, 2000 bp sequences upstream of major related genes were analyzed. Results indicated that ABA significantly up-regulated the expression levels of major genes related to carotenoids and flavonoids biosynthesis (ranging from 2.08 to 35 folds) and initiated the accumulation of carotenoids, phenolics and flavonoids by 2 or 4 days earlier than that in control. However, results demonstrated that the exogenous ABA could not significantly affect tomato color development without ethylene. The outcome of gene promoter analysis revealed that, besides single existence of ABRE or ERE motifs, 10 of 23 genes involved in carotenoids biosynthetic pathway, and 10 of 40 genes involved in flavonoid biosynthesis pathway possess both ABRE and ERE motifs in their 2000 bp upstream sequences, suggesting that ABA and ethylene may affect fruit color development via the collaborative regulation of these genes.

MADS-box genes, which encode highly conserved DNA-binding transcriptional factors, can regulate developmental processes in plants. FaMADS1a has not been functionally analyzed in non-climacteric fruit to date. In this study, one strawberry ( Fragaria × ananassa ) MADS-box gene, FaMADS1a , was cloned and its tissue-specific expression profiles were analyzed. FaMADS1a expressed in petal and fruit, and its expression levels decreased significantly during fruit ripening. Multiple sequence alignments suggested that FaMADS1a protein exhibited conserved MADS_MEF2_like motif, K-box region, MADS domain, SRF-TF motif and ARG80 domain. Phylogenetic analysis revealed that FaMADS1a belonged to the SEP1/2 clade. Phytohormone abscisic acid (ABA) suppressed FaMADS1a expression but accelerated the ripening process and anthocyanin-related gene expressions, while indole-3-acetic acid (IAA) induced FaMADS1a expression with delayed ripening phenotype and reduced expressions of anthocyanin-related genes. The pBI121 vector-mediated over-expression of FaMADS1a reduced the expressions of four anthocyanin-related genes and delayed fruit ripening compared to the control. Results suggested that FaMADS1a played a negative role in anthocyanin accumulation of strawberry fruit via repressing FaPAL6 , FaCHS , FaDFR and FaANS .

Sucrose metabolism is a fundamental process during tomato ripening. Studies have shown the role of the phytohormone methyl jasmonate (MeJA) in tomato fruit ripening. However, the role of MeJA in regulating sucrose metabolism in tomato is still unclear. In this study, mature green cherry tomato fruit were infiltrated with MeJA (0.5 mM) or sterile deionized water (control). The changes in color, firmness, and ethylene production in fruit, the contents of sucrose, glucose and fructose, and the enzymatic activities and the expression levels of key genes associated with sucrose metabolism were determined periodically during a storage period of 16 d. MeJA-treated fruit showed a significant acceleration in ripening, with higher a* value and ethylene production and lower firmness. MeJA treatment enhanced sucrose phosphate synthase (SPS) activity, whereas it inhibited acid invertase (AI) and neutral invertase (NI) activities. These changes in enzyme activities together resulted in a significantly higher sucrose content and lower glucose and fructose contents. Furthermore, exogenous MeJA upregulated the gene expression levels of sucrose-phosphate synthase1–4 (SPS1-4) and sucrose-phosphate phosphatase2 (SPP2), which were associated with sucrose biosynthesis, and downregulated those related to sucrose degradation, except for sucrose synthase2 (SUS2) and SUS3. The findings indicated that exogenous MeJA might alter sucrose metabolism during tomato ripening by regulating the enzymatic activities and gene expression levels. This research provides valuable information to elucidate the mechanisms via which MeJA regulates tomato sucrose metabolism.

It is difficult to preserve fresh shiitake mushroom (Lentinula edodes (Berk.) sing) partly because of the rapid deterioration of texture (softening or lignification). In this study, we developed a storage model in which tissue softening was induced to analyse the relationship between changes in firmness and alterations in cell wall chemical components as well as their metabolism. The results showed that the treatment group accumulated more CO2 and contained less O2 because of the poorer permeability in package. The contents of glucan and chitin in the treatment group decreased from 241.3 ± 13.2 mg g−1 and 46.3 ± 1.2 mg g−1 to 157.3 ± 11.2 mg g−1 and 18.0 ± 1.0 mg g−1 (P

Auxin-ethylene interactions are crucial for fruit ripening processes. However, the molecular basis of the regulatory network of auxin-ethylene interaction during ripening is still not very clear. To reveal the potential molecular mechanism of ethylene-auxin interplay in tomato ( Solanum lycopersicum L.) fruit ripening, global transcriptome profiling analysis was performed on cherry tomato fruit treated with auxin, ethylene or the combination of the two hormones. The results showed that ethylene modulated auxin transport, metabolism and signaling processes by affecting the expression patterns of genes encoding auxin carrier proteins, aldehyde dehydrogenase and primary auxin-responsive proteins. Most genes involved in ethylene biosynthesis and signaling were regulated 7 days after treatment with exogenous auxin. Furthermore, the expression levels of mitogen-activated protein kinase ( MAPK ) and of ubiquitination-related genes were altered in auxin-treated fruit, suggesting that auxin regulates ethylene metabolism and signaling via complicated mechanisms. The potential interaction points in auxin-ethylene crosstalk were also identified and a model was proposed. Our analyses provide a global insight into the ethylene-auxin interaction and predict the potential regulators in the crosstalk of the two hormones during the fruit ripening process.

The effects of thermal treatment on the ultrastructure and quality of Chilgoza pine nuts stored at near-freezing temperature were investigated. The moisture content of pine nuts was adjusted to 13.3%, compared to the initial 17.3% moisture content. Thermal treatment improved the storage stability. The hydrolysis of lipids was delayed in low-moisture pine nuts, resulting in a significant inhibition of free fatty acid accumulation in pine nuts. Low-moisture pine nuts also showed lower peroxide and thiobarbituric acid (TBA)​ values compared with the control. Ultrastructure characterization revealed that thermal treatment maintained the cell integrity, deferred the degradation of the plasmalemma and protected the internal lipid droplet. Thermal treatment better retained the antioxidant components, including total phenolics and vitamin E, and reduced the activities of lipase and lipoxygenase in pine nuts. These results indicated that thermal treatment could retard the senescence and deterioration of quality in pine nuts stored at a near-freezing temperature. Se investigaron los efectos del tratamiento térmico en la ultrastructura y la calidad del piñón de pino Chilgoza almacenado a una temperatura cercana a congelación. El contenido de humedad de los piñones de este pino fue de 13,3%, en comparación con el contenido de humedad inicial de 17,3%. El tratamiento térmico mejoró la estabilidad de almacenamiento. La hidrólisis de los lípidos se retardó en los piñones de pino de baja humedad, resultando en una inhibición significativa de la acumulación de ácidos grasos libres en los piñones. Los piñones de pino de baja humedad también mostraron unos índices bajos de peróxido y TBA en comparación con la muestra control. La caracterización de la ultrastructura reveló que el tratamiento térmico mantuvo la integridad de las células, atrasó la degradación de la plasmalema y protegió la gota lipídica interna. El tratamiento térmico retuvo de forma más favorable los componentes antioxidantes, como el total fenólico y la vitamina E, además redujo la actividad de la lipasa y la lipoxigenasa en los piñones. Estos resultados indicaron que el tratamiento térmico podría retardar la senescencia y la deterioración de la calidad de los piñones almacenados a una temperatura cercana a la congelación.

Auxin is an important plant hormone and plays crucial roles in regulating fruit ripening. The delay of ripening after auxin treatment has been found in tomato and other fleshy fruit. However, the influence of auxin on metabolites alteration during tomato ripening period has not been extensively studied. To investigate the impact of exogenous auxin on tomato fruit quality, pigment metabolism, primary metabolite profiling, and the expression of selected ripening-related transcription factor genes were analyzed. The results showed that exogenous auxin significantly interfered the accumulation and conversion of pigments, total phenolics and flavonoids but did not largely influence the final content of these compounds in full ripe tomato fruit. Dramatic changes on the content of primary metabolites were induced by auxin during tomato ripening period and the alterations were not able to be completely restored at the end of ripening. The contents of citric acid, threonic acid and succinic acid were increased whereas alanine and aspartic acid accumulation was repressed in auxin-treated fruit. The expression patterns of transcription factor genes related to ripening were also disturbed by exogenous auxin. The present study provided an overall insight on how auxin regulates pigment and primary metabolite accumulation during ripening stage and offered useful information for further investigation of auxin impact on fruit quality.

Fresh button mushrooms (Agaricus bisporus) were harvested and treated with a solution of 1.5% CaCl2 + 0.5% citric acid and stored for 16 days at 12 °C. The effects of this treatment on firmness, weight, color, cell wall compositions (cellulose and chitin) and cell wall degrading enzymes (cel1ulase, beta-1, 3 glucanase, chitinase and phenylalanine ammonialyase) were investigated during post-harvest storage. The expressions of major genes (Cel1, Glu1, Chi1 and PAL1) involved in cell wall degradation during post-harvest storage were also monitored. The results revealed that the post-harvest chemical treatment maintained better firmness, weight, color and inhibited cellulase, beta-1, 3 glucanase, chitinase and phenylalanine ammonialyase activities. These findings showed that the down-regulation of cell wall degrading enzymes is a possible mechanism that delays the softening of button mushrooms by the application of combined chemical treatment.

Wound-induced suberization is an essentially protective healing process for wounded fruit to reduce water loss and microbial infection. It has been demonstrated that abscisic acid (ABA) could promote wound suberization, but the molecular mechanism of ABA regulation remains little known. In this study, the transcript level of Achn030011 (designated as AchnKCS), coding a β-ketoacyl-coenzyme A synthase (KCS) involved in suberin biosynthesis, was found to be significantly upregulated by ABA in wounded kiwifruit. A bZIP transcription factor (Achn270881), a possible downstream transcription factor in the ABA signaling pathway, was screened and designated as AchnbZIP12 according to its homology with related Arabidopsis transcription factors. A yeast one-hybrid assay demonstrated that AchnbZIP12 could interact with the AchnKCS promoter. Furthermore, significant trans-activation of AchnbZIP12 on AchnKCS was verified. The transcript level of AchnbZIP12 was also upregulated upon treatment with ABA. These results imply that AchnbZIP12 acts as a positive regulator in ABA-mediated AchnKCS transcription during wound suberization of kiwifruit.

Chitin-glucan complex (CGC), the main component of fungal cell wall, is reported to have wide applications in the food and pharmaceutical industries because of its physical and physiological activities. In this study, CGC was extracted from the fruiting body of Termitomyces albuminosus (Berk.) Heim with the treatments of deproteination, demineralization and depigmentation to obtain a yield of 13.46%, and its properties were investigated. The results indicated that CGC from T. albuminosus contained glucan and chitin in a molar ratio of 46:54, with very low contents of proteins and inorganic salts. The chitin in CGC was in the α-form, with crystallinity index of 64.81% and degree of acetylation of 65.40%. The surface morphology of CGC was dense and firm with no nanofibers and nanopores as observed by scanning electron microscopy, and the peak degradation temperature was determined to be 314.88 °C. This study suggested that CGC from T. albuminosus was promising to be an alternative source of crustacean chitinous products in the industry of food, medicine, waste water treatment and so on in the future.

Phytohormone methyl jasmonate (MeJA) plays an important role in fruit ripening. This research aimed to investigate the regulation of MeJA in ethylene biosynthesis and signal transduction during postharvest tomatoes ripening. After mature green cherry tomatoes were infiltrated with MeJA (0.5 mM) or deionized water (control) respectively, fruit colour and firmness, ethylene production, the activities and expressions of ACS and ACO, as well as the expressions of major genes involved in ethylene signal transduction were periodically monitored. Results showed that a significant acceleration in ripening in MeJA-treated fruit was observed, along with the accelerated changes of ethylene production, the enhanced activities and expression levels of ACS and ACO. The expression levels of ETR3, ETR4, ETR6, ETR7, EIN2, EIL2, EIL3, EIL4 and ERF1 were up-regulated (from 1.26- to 6.50-fold) by MeJA during tomatoes ripening. The expression of CTR1, however, was down-regulated (from 0.23- to 0.54-fold). Moreover, the expression of EIL1 was positively regulated at the early ripening stage whereas negatively regulated at the late ripening stage (11.76-/0.39-fold), whereas the expressions of CTR3 and CTR4 showed the opposite expression patterns (0.15-/7.78-fold, 0.48-/2.00-fold). Results suggested the up-regulation of the genes associated with ethylene biosynthesis, as well as the up-regulated transcriptional levels of the most genes involved in ethylene signal transduction, leading to the increase of ethylene production, response and action, would be one of the major mechanisms of MeJA in accelerating postharvest tomatoes ripening.

Effect of exogenous nitric oxide (NO) on polyamines (PAs) catabolism, γ-aminobutyric acid (GABA) shunt, proline accumulation and chilling injury of banana fruit under cold storage was investigated. Banana fruit treated with NO sustained lower chilling injury index than the control. Notably elevated nitric oxide synthetase activity and endogenous NO level were observed in NO-treated banana fruit. PAs contents in treated fruit were significantly higher than control fruit, due to the elevated activities of arginine decarboxylase and ornithine decarboxylase. NO treatment increased the activities of diamine oxidase, polyamine oxidase and glutamate decarboxylase, while reduced GABA transaminase activity to lower levels compared with control fruit, which resulted the accumulation of GABA. Besides, NO treatment upregulated proline content and significantly enhanced the ornithine aminotransferase activity. These results indicated that the chilling tolerance induced by NO treatment might be ascribed to the enhanced catabolism of PAs, GABA and proline.

Three annexin genes may be involved in the ripening progress of strawberry fruit. Phytohormones and calcium regulate the expressions of three annexin genes during strawberry fruit ripening. Plant annexins are multi-functional membrane- and Ca2+-binding proteins that are involved in various developmental progresses and stress responses. Three annexins FaAnn5a, FaAnn5b and FaAnn8 cDNA obtained from strawberry fruit encode amino acid sequences of approximately 35 kDa containing four annexin repeats, Ca2+-binding site, GTP-binding motif, peroxidase residue, and conserved amino acid residues of tryptophan, arginine and cysteine. During fruit development, the transcript levels of FaAnn5a and FaAnn5b increased while FaAnn5b declined after 3/4R stage. The expression patterns of annexins suggested their potential roles in strawberry fruit development and ripening. Expressions of annexin genes were also highly correlated with hormone levels. In addition, exogenous abscisic acid (ABA) enhanced the expressions of FaAnn5a and FaAnn8 while exogenous auxin (IAA) retarded it. However, both ABA and IAA promoted the transcript levels of FaAnn5b, indicating the independent regulation of annexins in fruit likely due to multi-functions of their large family. The responses of annexin genes to exogenous ABA and IAA inhibitors verified the involvement of annexins in plant hormone signaling. Besides, calcium restrained the expressions of FaAnn5s (FaAnn5a and FaAnn5b) but promoted the expression of FaAnn8. Effects of calcium and ethylene glycol tetraacetic acid (EGTA) on the transcript levels of annexins confirmed that calcium likely mediated hormone signal transduction pathways, which helped to elucidate the mechanism of calcium in fruit ripening. Therefore, FaAnn5s and FaAnn8 might be involved in plant hormones’ regulation in the development and ripening of strawberry fruit through calcium signaling in the downstream.

Fruits are prone to suffer water-deficit stress and accelerated senescence after harvest. To understand the effect of postharvest water-deficit on the senescence progress of strawberry fruit, fruit peduncles were dipped into water or abscisic acid solution and stored at 20 °C with 50% relative humidity in the dark. The results showed that detached fruit without water supply through the peduncles suffered serious water-deficit stress with great weight loss and low moisture content. However, fruit absorbing water through their peduncles successfully avoided the water-deficit stress with a slight change of weight loss and moisture content. Water-deficit significantly promoted anthocyanin levels with increased PAL, C4H and DFR activities. The expressions of transcriptional factors that regulate anthocyanin biosynthesis ( FaMYB1 , FabHLH3 and FaTTG1 ) were also up-regulated under water-deficit stress. Meanwhile, stress elevated the abscisic acid level as well as FaNCED1 and FaASR expression in strawberry fruit. Furthermore, exogenous ABA application exhibited the similar features with water-deficit stress. These results suggested that postharvest water-deficit would accelerate anthocyanin accumulation in strawberry fruit and that abscisic acid may play a role in the response to water-deficit stress.

Fruit aroma development depends on ripening. Abscisic acid (ABA) has been reported to be involved in the regulation of tomato fruit ripening. In the present study, the effects of exogenous ABA on aromatic volatiles in tomato fruit during postharvest ripening were studied. The results showed that exogenous ABA accelerated color development and ethylene production as well as the accumulation of carotenoids, total phenolics and linoleic acid in tomato fruit during ripening. Moreover, exogenous ABA increased the accumulation of volatile compounds such as 1-peten-3-one (2.06-fold), β-damascenone (1.64-fold), benzaldehyde (3.29-fold) and benzyl cyanide (4.15-fold); induced the expression of key genes implicated in the biosynthesis pathways of aromatic volatiles, including TomloxC, HPL, ADH2, LeCCD1B and SlBCAT1 (the values of the log2 fold changes ranged from -3.02 to 2.97); and promoted the activities of lipoxygenase (LOX), hydroperoxide lyase (HPL) and alcohol dehydrogenase (ADH). In addition, the results of promoter analyses revealed that cis-acting elements involved in ABA responsiveness (ABREs) exist in 8 of the 12 key genes involved in volatile biosynthesis, suggesting that ABA potentially affects aromatic volatile emissions via the regulation of gene expression profiles.

The perception and signal transduction of the plant hormone abscisic acid (ABA) are crucial for strawberry fruit ripening, but the underlying mechanism of how ABA regulates ripening-related genes has not been well understood. By employing high-throughput sequencing technology, we comprehensively analyzed transcriptomic and miRNA expression profiles simultaneously in ABA- and nordihydroguaiaretic acid (NDGA, an ABA biosynthesis blocker)-treated strawberry fruits with temporal resolution. The results revealed that ABA regulated many genes in different pathways, including hormone signal transduction and the biosynthesis of secondary metabolites. Transcription factor genes belonging to WRKY and heat shock factor (HSF) families might play key roles in regulating the expression of ABA inducible genes, whereas the KNOTTED1-like homeobox protein and Squamosa Promoter-Binding-like protein 18 might be responsible for ABA-downregulated genes. Additionally, 20 known and six novel differentially expressed miRNAs might be important regulators that assist ABA in regulating target genes that are involved in versatile physiological processes, such as hormone balance regulation, pigments formation and cell wall degradation. Furthermore, degradome analysis showed that one novel miRNA, Fa_novel6, could degrade its target gene HERCULES1, which likely contributed to fruit size determination during strawberry ripening. These results expanded our understanding of how ABA drives the strawberry fruit ripening process as well as the role of miRNAs in this process., Crop genetics: pathways to ripe strawberries Researchers in China have uncovered the genetic factors through which the plant hormone ABA controls strawberry ripening. Zisheng Luo’s team at Zhejiang University used high-throughput sequencing to compare gene expression in strawberry plants after they were treated with ABA or an ABA-blocker. They discovered that ABA changes the expression of genes related to other hormones, metabolite synthesis, and breaking down cell walls. The team also checked the expression of short RNA molecules which regulate gene expression, known as microRNAs (miRNAs). They found 26 miRNAs which changed expression in response to ABA, six of which were novel, and identified 18 genes regulated by these miRNAs, including a cell wall gene which may be involved in fruit enlargement. These findings clarify the molecular mechanisms linking ABA with strawberry ripening and lay the groundwork for detailed functional studies.

Phytohormones regulate numerous aspects of plant growth and development. Green-mature banana fruit were treated with deionized water (control), abscisic acid (ABA), indole-3-acetic acid (IAA) and ABA + IAA, respectively, to investigate the role of ABA and IAA in fruit ripening. Results showed that ABA accelerated fruit ripening, but IAA delayed the process. However, treatment of ABA + IAA showed little difference in fruit color and firmness. The acceleration of ABA and delay of IAA on banana ripening process seems to be neutralized by ABA + IAA. Digital gene expression revealed that ABA + IAA treated fruit maintained the similar color phenotype with the control by regulating the expression of chlorophyll degradation-related gene PaO (GSMUA_Achr6G25590_001), and carotenoid biosynthesis-related genes DXR (GSMUA_Achr3G20790_001) and PSY (GSMUA_Achr2G12480_001, GSMUA_Achr4G17270_001, GSMUA_Achr4G17290_001). Moreover, ABA + IAA treated fruit maintained the similar softening phenotype with the control by adjusting the expression of pectin degradation-related genes PME (GSMUA_Achr3G05740_001) and PL (GSMUA_Achr6G28160_001, GSMUA_Achr7G04580_001). ABA + IAA treatment nearly abolished the action of individual ABA or IAA through equilibrating the expression of specific genes involved in chlorophyll degradation, carotenoid biosynthesis and pectin degradation pathways in the postharvest ripening of banana. The interaction between ABA and IAA might exercise as an antagonistic mechanism of neutralizing the specific gene expression either induced by ABA or reduced by IAA in the postharvest ripening of banana.

Effects of postharvest nitric oxide (NO) treatment on energy metabolism and chilling injury in cold-stored banana fruit were investigated. Banana fruit were treated with 0.05 mM NO donor sodium nitroprusside, and then stored at 7 °C for up to twenty days. NO treatment apparently inhibited the development of chilling injury. The contents of adenosine triphosphate (ATP) and energy charge in the NO-treated fruit were significantly higher than control fruit. Meanwhile, the activities of enzymes involved in energy metabolism, including H+-ATPase, Ca2+-ATPase, succinic dehydrogenase and cytochrome C oxidase were markedly enhanced by NO treatment. In addition, notably elevated activities of fructokinase, glucokinase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were observed in NO-treated banana fruit. These results indicated that NO could enhance chilling tolerance of banana fruit through maintaining high levels of energy status and inducing enzyme activities involved in energy metabolism during cold storage.

Because of the short shelf life of button mushroom, its long-term preservation efforts gained momentum. In this study, we evaluated the efficiency of chemical dips for quality maintenance of button mushrooms during storage and compared three different treatments: water (CK), T1 (2.5% w/v CaCl2, 0.5% w/v citric acid) and T2 (2.5% w/v CaCl2, 0.5% w/v citric acid, 3% w/v sorbitol). Changes in weight, firmness, color, malondialdehyde (MDA), hydrogen peroxide (H2O2), hydroxyl radical (-OH), superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) were determined. As compared to control, T1 and T2 maintained weight, color and texture during storage. Downregulations in H2O2, −OH and MDA contents were observed, whereas the activities of SOD, CAT, POD and APX were increased. T2 was more efficient in maintaining quality and reducing oxidative stress of button mushrooms within 6 days, while T1 showed the same effects for 12 days as compared to CK. Practical Applications Mushrooms are nutritionally and medicinally important and delicate food stuff. Several techniques have been employed for the preservation of mushrooms in order to cater the shorter shelf life problem of mushrooms. The integrated treatment employed in our study showed significant enhancement in the shelf life of mushrooms at 12C for 12 days. From this study, it can be assumed that these treatments can increase the shelf life of mushrooms for 1 week at room temperature and 1 month at 4C. This treatment is considered cost-effective, durable and safe. The components are easily available and have no side effects on food, consumer and environment. Furthermore, it can be introduced in domestic as well as in commercial levels for preservation of mushrooms. It can increase the mushroom shelf life and can decrease mushroom spoilage. This study suggests further investigations about application of this treatment for preservation of other perishable food stuffs.

In this study, the antioxidant activities of different parts of lotus (Nelumbo nuficera Gaertn) rhizome were compared. The total phenolic content of lotus rhizome was determined, and Ferric reducing antioxidant power (FRAP) assay, 1,1-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical-scavenging assay and β-carotene-linoleic acid assay were performed to assess the antioxidant activity of lotus rhizome. Results showed that there was a significant difference in total phenolic content and antioxidant activity between any two of four parts of lotus rhizome. The order of total phenolic content and antioxidant activity in different parts of lotus rhizome was as follows: peel of old lotus rhizome > peel of young lotus rhizome > flesh of old lotus rhizome > flesh of young lotus rhizome. The total phenol content is significantly positive correlated with the antioxidant activity in different parts of lotus rhizome. This study has provided a basis for further exploring the antioxidant components in lotus rhizome.

This study evaluated the effects of composite chemical pretreatment on the quality of postharvest button mushrooms. Three different treatments, including (T1) control (water), (T2) 1 mmol L −1 Na 2 EDTA + 10 mmol L −1 CaCl 2 and (T3) 1 mmol L −1 Na 2 EDTA + 2.5% CaCl 2 + 0.5% citric acid + 2.5% sorbitol were used for pretreatments. The results showed that T3-treated samples maintained good firmness and color and had less weight loss during the postharvest storage. Lower levels of H 2 O 2 , − OH and low malondialdehyde content (MDA) were observed in T3 compared with T1 and T2 samples. Significantly higher soluble protein contents and higher activities in the antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) were observed in T3 compared with T1 and T2 at the end of the storage period ( P

To study the detachment stress on the ripeness of strawberry fruit, physiological characteristics of strawberry fruit on and off plant during ripeness and senescence processes were investigated. The results indicated that the ripeness of strawberry fruit upon detachment was accelerated, in terms of firmness, soluble solid content and especially color development. The color of fruit off plant changed rapidly from white to full red in 1–2 days. The respiratory rate in fruit off plant was strengthened, higher than that on plant. Abscisic acid level and ethylene production in fruit off plant were also higher than those on plant and auxin degradation was exacerbated by detachment. Expression levels of FaMYB1, FabHLH3 and FaTTG1 were generally reduced with phenotypes of redder color and more anthocyanin accumulation in fruit off plant. Results also suggested that the detachment initially stimulated ethylene and abscisic acid production and auxin degradation, which modulated ripening-related gene expression and at last enhanced fruit pigmentation.

Effects of 1 mM abscisic acid (ABA) and 4.1 kJ/m 2 UV-C radiation on quality, antioxidant capacity, anthocyanin contents, and anthocyanin biosynthetic enzyme activities of large green strawberry fruit stored at 20 °C were evaluated. Results showed that ABA promoted color formation, firmness decrease, soluble solids content and anthocyanin accumulation while UV-C inhibited these processes. Activities of phenylalanine ammonia-lyase, tyrosine ammonia-lyase and p -coumarate ligase were immediately upregulated by approximately 50% with UV-C radiation but were inhibited, including dihydroflavonol 4-reductase especially on day 3 or 4. UV-C radiation had little effect on activity of cinnamate 4-hydroxylase (C4H). ABA enhanced activities of anthocyanin biosynthetic enzymes except C4H. These data indicated that the stimulatory effect of ABA on strawberry anthocyanin accumulation was related to enhancement of biosynthetic enzyme activities, while the effects of UV-C were more transient. In addition, it appeared that C4H was not a rate-limiting enzyme in the strawberry anthocyanin biosynthesis pathway.

Mature green cherry tomato fruit were harvested and treated with ultraviolet-C (UV-C) irradiation at a predetermined dose of 4.2 kJ m −2 , and stored at 18 °C for 35 days. The effects of UV-C treatment on color change, pigment contents, and the expression of major genes involved in carotenoid metabolism, including Psy 1, Pds , Lcy - β , and Lcy - ɛ , encoding phytoene synthase, phytoene desaturase, lycopene β-cyclase and lycopene ɛ-cyclase, respectively, were examined. The UV-C treated fruit developed a pink red color in contrast to the normal orange red color of control fruit. Lycopene accumulation during ripening in UV-C treated fruit was significantly inhibited but its final content was not affected. However, both accumulation and final content of β-carotene were significantly suppressed in UV-C treated fruit. The lower content of β-carotene, leading to a higher lycopene to β-carotene ratio, is probably responsible for the altered color phenotype in UV-C treated fruit. Psy 1, a major gene involved in lycopene synthesis was inhibited by UV-C irradiation. Significantly suppressed expression of Lcy-β gene was also observed in UV-C treated fruit. Thus it is possible that the lower transformation from lycopene to carotenes contributed to the relatively stable content of lycopene.

Fresh button mushrooms (Agaricus bisporus) were harvested and treated with a solution of 1.5% CaCl

Mature green cherry tomato fruit were harvested and treated with ultraviolet-C (UV-C) irradiation at a predetermined dose of 4.2 kJ m −2 and stored at 18 °C for 35 days. The effects of UV-C treatment on firmness, cell wall compositions (pectin and cellulose), cell wall ultra-structure, levels of ethylene production, and activities of cell wall degrading enzymes in the fruit were investigated during storage. Major genes involved in cell wall degradation ( PME 2.1, Cel 1, PG cat and Exp 1) were also checked. Fruit firmness was better maintained in UV-C treated fruit corresponding with higher contents of cellulose and acid-soluble pectin. Transmission electron microscopy indicated that UV-C irradiation retarded cell wall disassembly in the pericarp. Ethylene production was significantly inhibited by UV-C treatment. The UV-C treatment also suppressed the transcriptional expression of PME2.1 , Cel1 , PGcat and Exp1 genes, and inhibited pectin methylesterase (PME; EC 3.1.1.11), polygalacturonase (PG; EC3.2.1.15) and cellulase (EC3.2.1.4) activities during storage. These results suggested that the inhibition of ethylene production, which in turn down-regulated expression of genes encoding cell wall degrading enzymes, might be one of the possible mechanisms of UV-C delaying tomato fruit softening.

The effect of exogenous nitric oxide (NO) on chilling injury to banana fruit was investigated. Banana fruit was treated with NO donor sodium nitroprusside of 0.05 mM at 20 °C for 10 min and then stored at 7 °C for up to 20 days. Banana fruit treated with NO sustained a lower chilling injury index and higher firmness and kept lower electrolyte leakage and malondialdehyde content than the control. Further investigation showed that NO treatment enhanced activities of guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase compared to the control. It also maintained higher ascorbic acid, reduced glutathione content, and total antioxidant capacity but reduced hydrogen peroxide and superoxide anion to lower levels compared to control fruit during storage. NO treatment significantly enhanced the accumulation of total phenolics and proline, which resulted from the increased activities of phenylalanine ammonia-lyase and Δ¹-pyrroline-5-carboxylate synthetase and decreased proline dehydrogenase activity. We proposed that the enhanced chilling tolerance induced by NO treatment may result from the reduction of oxidative stress and proline accumulation.

Changes in quality of low-moisture conditioned pine nuts (Pinus gerardiana) under near freezing temperature storage were investigated. Nuts were adjusted to different moisture content (17.3% ± 0.42, 15.1% ± 0.26, and 13.3% ± 0.24) with 35°C, 20%RH, sealed in air-tight jars and stored at −3 and −1°C for 12 months. In general, free fatty acid content and peroxide value of the nuts increased, while sensory quality decreased during the storage. Low-moisture nuts had lower respiration, free fatty acid content, and peroxide value. Nuts stored at −3°C had less visible mold infection and browning percentage than at −1°C. Low-moisture treatment exerted a slight negative effect on texture, but had significant preservative effects on color, odor, and taste during storage. Overall, integration of low-moisture conditioning and near freezing temperature storage can be a promising non-chemical way for maintaining the postharvest quality and extending shelf-life of pine nuts.

Summary To investigate the effect of temperature and relative humidity (RH) on the absorption kinetics of self-activated and moisture-activated O2 scavengers for packaged food, kinetic parameters of each O2 scavenger were evaluated at 43%, 75% or 100% RH and at 10, 25 and 40 °C respectively. Absorption kinetics was well described by a first-order reaction with an Arrhenius type behaviour. For moisture-activated O2 scavengers, a proper high RH was needed to ensure a high O2 absorption capacity, as average O2 absorption capacity was 3.82 mL at 43% RH and 43.40 mL at 75% RH. When the temperature increased, O2 absorption rate constant ascended from 10 °C to 40 °C on an average of 0.153 and 0.306 h−1 in moisture-activated and self-activated O2 scavengers respectively. We could take the effect of temperature and RH into account when we chose different types of iron-based O2 scavengers for packaged food.

Changes in the content of bioactive components, oxidative stability, and radical scavenging capacity of pine nut oils extracted from kernels roasted for different times (0–60 min) at 150°C were determined. Oil extracted from kernels roasted for 30 min demonstrated the highest oxidative stability. The browning index which indicates extent of Maillard reaction significantly (p

The role of sucrose as a signal molecule in plants was in debate for a long time, until recently, it gradually becomes more prominently accepted. Sucrose plays roles in a vast array of developmental processes in plants, however, its function in fruit ripening has not been well elucidated. In this study, the influence of exogenous sucrose treatment (500 mM) on postharvest tomato fruit ripening was investigated. It was found that, in comparison with mannitol treatment (500 mM, set as control), sucrose accelerated the ripening process with higher levels of respiration rate and ethylene production during the storage. Sucrose treatment up-regulated its biosynthetic genes, whilst stimulated expressions of genes encoding degradation related enzymes in the fruits. However, higher sucrose content was observed in sucrose-treated fruits only in the first few days. In addition, sucrose application had minor effect on the contents of its degrading products, glucose and fructose. Moreover, exogenous sucrose treatment up-regulated expressions of ethylene biosynthetic genes, and promoted ethylene signal transduction via influencing critical genes of the signaling pathway in different patterns. These results indicate that sucrose stimulates tomato fruit ripening may through mediating its own metabolism, which facilitates nutrients fluxes and metabolic signaling molecules activation, and also by enhancing ethylene biosynthesis and signal transduction.

Abscisic acid (ABA) is a critical plant hormone for fruit ripening and adaptive stress responses in strawberry. Previous high-throughput sequencing results indicated that ABA-insensitive (ABI)5, an important transcription factor in the ABA signaling pathway, was a target for a novel microRNA (miRNA), Fan-miR73. In the present study, exogenous ABA treatment was found to accelerate fruit ripening through differentially regulating the transcripts of ABA metabolism and signal transduction related genes, including NCED1, PYR1, ABI1 and SnRK2.2. Expression of Fan-miR73 was down-regulated in response to exogenous ABA treatment in a dosage-dependent manner, which resulted in an accumulation of ABI5 transcripts in the ripening-accelerated fruits. In addition, both UV-B radiation and salinity stress reduced the transcript levels of Fan-miR73, whereas promoted ABI5 expression. Furthermore, high negative correlations between the transcriptional abundance of Fan-miR73 and ABI5 were observed during ripening and in response to stress stimuli. These results enriched the possible regulatory role of miRNA involved in the post-transcriptional modification of ABI5 during strawberry ripening, as well as responses to environmental stresses.

Auxin has been shown to modulate the fruit ripening process. However, the molecular mechanisms underlying auxin regulation of fruit ripening are still not clear. Illumina RNA sequencing was performed on mature green cherry tomato fruit 1 and 7 days after auxin treatment, with untreated fruit as a control. The results showed that exogenous auxin maintained system 1 ethylene synthesis and delayed the onset of system 2 ethylene synthesis and the ripening process. At the molecular level, genes associated with stress resistance were significantly up-regulated, but genes related to carotenoid metabolism, cell degradation and energy metabolism were strongly down-regulated by exogenous auxin. Furthermore, genes encoding DNA demethylases were inhibited by auxin, whereas genes encoding cytosine-5 DNA methyltransferases were induced, which contributed to the maintenance of high methylation levels in the nucleus and thus inhibited the ripening process. Additionally, exogenous auxin altered the expression patterns of ethylene and auxin signaling-related genes that were induced or repressed in the normal ripening process, suggesting significant crosstalk between these two hormones during tomato ripening. The present work is the first comprehensive transcriptome analysis of auxin-treated tomato fruit during ripening. Our results provide comprehensive insights into the effects of auxin on the tomato ripening process and the mechanism of crosstalk between auxin and ethylene.

The dark colour of soybean oligosaccharides extract from sweet slurry, a byproduct of soybean sheet production limits its full utilisation in the food industry. Adsorption resins were performed to remove the coloured impurity. The effects of operation parameters on decolourisation efficiency and adsorption isotherm were investigated. The experimental results revealed that more than 70% of the coloured impurity was removed in final products by macroporous resin DM-130 after 24 h contact. Temperature had significant influence on adsorption. The adsorption process and the thermodynamic data indicated that the process was possibly exothermic and spontaneous. The optimum ratio of resin mass/oligosaccharides solution was approximately 0.13 g/ml. The adsorption isotherm agreed with Freundlich model, indicating that the adsorption process was monolayer and heterogeneous. Adsorption kinetics fitted the pseudo-second-order kinetic model. The second step of intra-particle diffusion would be the rate-controlling step.

The functional properties and bioactivities of the pine nut protein isolates (PPI) and its enzymatic hydrolysates (PPH) prepared with Alcalase at 5 %, 10 %, 15 % and 25 % degree of hydrolysis (DH) were studied. The solubility of PPH significantly increased (p