Auxin and abscisic acid regulate strawberry fruit ripening and senescence through cross-talk of their signal transduction pathways that further modulate the structural genes related to physico-chemical properties of fruit.The physiological and transcriptomic changes in harvested strawberry fruits in responses to IAA, ABA and their combination were analyzed. Exogenous IAA delayed the ripening process of strawberries after harvest while ABA promoted the postharvest ripening. However, treatment with a combination of IAA and ABA did not slow down nor accelerate the postharvest ripening in the strawberry fruits. At the molecular level, exogenous IAA up regulated the expressions of genes related to IAA signaling, including AUX/IAA, ARF, TOPLESS and genes encoding E3 ubiquitin protein ligase and annexin, and down regulated genes related to pectin depolymerization, cell wall degradation, sucrose and anthocyanin biosyntheses. In contrast, exogenous ABA induced genes related to fruit softening, and genes involved in signaling pathways including SKP1, HSPs, CK2, and SRG1. Comparison of transcriptomes in responses to individual treatments with IAA or ABA or the combination revealed that there were cooperative and antagonistic actions between IAA and ABA in fruit. However, 17 % of the differentially expressed unigenes in response to the combination of IAA and ABA were unique and were not found in those unigenes responding to either IAA or ABA alone. The analyses also found that receptor-like kinases and ubiquitin ligases responded to both IAA and ABA, which seemed to play a pivotal role in both hormones’ signaling pathways and thus might be the cross-talk points of both hormones.

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.

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.

The aim of the present study was to investigate the possible role of BAX and BI-1 genes in chilling injury of cucumber fruit. BAX and BI-1 gene expressions were assayed under 2 ± 1 °C. Meanwhile, cell death, cellular integrity, specific chromatin fragmentation and nucleus morphology in cucumber (Cucumis sativus L. cv. Zhexiu-1) fruits were determined. Results indicated that BAX and BI-1 genes were activated by low temperature and the expression level of the BAX was much higher than BI-1. At the same time, electrolyte leakage and cell death were increased coupled with nuclear envelope disassembly and DNA fragmentation during the occurrence of chilling injury. In addition, characteristic features of programmed cell death were induced as well as the initiation of chilling injury. The interaction of BAX and BI-1 might predetermine the cell life or death in response to cold stimulus.

Programmed cell death (PCD) is a genetically controlled and conserved process in eukaryotes during development as well as in response to pathogens and other stresses. BAX inhibitor-1 (BI-1) has been implicated as an anti-PCD factor which is highly conserved in plants. Sequence of putative cucumber BI-1 protein exhibited 77.7 % identity and 91.2 % positive value with the homologue Blast BI-1 protein of Arabidopsis thaliana (AtBI-1). This highly homologous protein to the AtBI-1 protein was named CsBI-1. This protein contains an open reading frame (ORF) of 250 amino acids with a BAX inhibitor domain and five transmembrane regions conserved among members of the BI-1 family. Primers designed by the cDNA of CsBI-1gene were used for further sequencing. Cell death in cold-stored cucumber developed concomitantly with increased expression of the CsBI-1 gene and reached maximum at day 6. However, cell death accelerated significantly after 9 d when sharp decrease of the CsBI-1 expression occurred. After warming to 20 °C, expression of the CsBI-1 gene was the highest at day 3, decreased afterwards, and the lowest expression was detected at day 9 when PCD obviously appeared. The overall results indicate that CsBI-1 is cucumber homologue of Arabidopsis thaliana AtBI-1 gene. CsBI-1 is a conserved cell death suppressor induced by cold stress and a negative regulator of PCD.

The aim of this study was to explore the artificial hibernation of crucian carp for waterless preservation and to characterize the quality and biochemical properties during and after the hibernation. Anesthetized crucian carp using eugenol were stored at 8 °C with 90 % oxygen and 95–100 % relative humidity for 38 h and then transferred to fresh water to recover. Liquid loss and cooking loss had no significant changes (p > 0.05). The total volatile basic nitrogen content and 2-thiobarbituric acid value in hibernated fish were significantly higher (p < 0.05) than fresh and recovered groups. Serum cortisol, glutamic-oxaloacetic transaminase (GOT), alkaline phosphatase (AKP), and acid phosphatase (ACP) activities significantly increased (p < 0.05) during hibernation, while glutamic-pyruvic transaminase (GPT) had no significant change (p > 0.05). Both ACP and AKP activities decreased upon the fish recovered, but only the ACP activity returned to normal. However, there were increased serum glucose concentration, GOT and GPT activities in recovered fish. On the basis of these findings, it can be concluded that the artificially hibernated life of crucian carp was 38 h by the combination of anaesthetizing and low temperature. The muscle quality would not be influenced, and most of the stress responses would disappear after hibernated fish recovered.

This study was to investigate the responses of phospholipase D (PLD) and lipoxygenase (LOX) to mechanical wounding in postharvest cucumber (Cucumis sativus L. cv. Biyu-2) fruits. Membrane-associated Ca2+ content, activities and gene expression of PLD and LOX, and contents of phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidic acid (PA) were determined in cucumber fruits following mechanical wounding. Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding, while membrane-associated Ca2+ content decreased. Accompanying with the increase of PLD and LOX activities, accumulation of PA and losses of PC and PI were observed in all fruits, but there were differences of degrees between wounded and control fruits. Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury. The activation of PLD and LOX might be the result of gene expression, which could be stimulated by the Ca2+ flowing from the membrane to the cytoplasm upon receiving the wounding signals.

The antioxidant properties of methanol extracts from daylily flowers during maturation were determined with antioxidant assays, including antioxidant activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging and reducing power. Antioxidant compounds, such as phenolic compounds, ascorbic acid and β-carotene were also analysed. Significant variation in antioxidant properties and involved compounds was observed between different maturity stages of daylily flowers. The highest antioxidant activity was observed at stage III (flower opening) accompanying the highest content of ascorbic acid and phenolic compounds, while no significant difference of β-carotene contents was observed among the four maturity stages. Four individual phenolics, such as (+)-catechin, chlorogenic acid, rutin and quercetin were identified and quantified by HPLC. (+)-Catechin was the main phenolic compound identified in daylily flowers, accounting for about 74.11% of total phenolics. Overall, daylily flowers at opening stage possess the highest functional benefit and thus would be the appropriate harvesting stage in view of the nutritional consideration.

Hot air drying and microwave drying were applied to dry fish fillets made of grass carp (Ctenopharyngodon idellus), and the correlative influences on nutritional and odorous properties were evaluated by proximate composition, protein solubility, amino acid composition, fatty acid composition, peroxide value, anisidine value, and odour evaluation. Drying resulted in a significant increase of protein but reduced fat content. There was lack of negative influence of the drying process on the amino acid composition of grass carp fillets. Both saturated and monounsaturated fatty acid contents decreased, while polyunsaturated fatty acids increased by an average of 23.8% after drying. Microwave-dried samples showed lower fat loss, higher protein solubility, and lower anisidine values than hot air-dried samples. There was no significant difference in odour quality between hot air-dried and microwave-dried samples. The present study provides a possible application of microwave drying as an efficient drying process for fish fillets.

The physicochemical changes in fresh sugarcane juice stored at 10 °C were studied by determining juice yield, color, reducing sugar, titratable acidity, viscosity, pH, polyphenol oxidase (PPO), sucrose neutral invertase (SNI) and total microbial count. Results showed that blanching of stems before squeezing effectively prevented degreening and/or browning, and reduced activities of PPO and SNI in fresh sugarcane juice. Added ascorbic acid delayed the increase of reducing sugar, titratable acidity, viscosity and total microbial count, and also prevented degreening and/or browning with reduced PPO and SNI activities in fresh sugarcane juice during storage. Addition of 0.1% ascorbic acid seemed to be more effective than blanching of sugarcane stems, and was able to maintain the quality of fresh sugarcane juice for up to 5 days at 10 °C. Deterioration of fresh sugarcane juice was demonstrated as a rapid increase of titratable acidity and viscosity with a obvious browning.

Sugarcane (Saccharum officinarum L. cv. Badila) was harvested at the mature stage and stored at 2, 10, and 20 °C for 30, 90, and 120 days, respectively. Metabolic changes in the contents of sucrose and reducing sugar in relation to the activities of soluble acid invertase (SAI), neutral invertase (NI) and sucrose-phosphate synthase (SPS), in sugarcane juice, were studied. Extractable juice, sucrose and vitamin C declined significantly with increasing storage temperatures, while respiration rate increased. There was a rapid increase in titratable acidity during storage, with a more rapid rate at higher temperatures. A sharp increase in reducing sugar was observed within 20 days at 20 °C and 70 days at 10 °C, followed by a rapid decrease. Both SAI and NI activities showed a sharp increase within 15 days at 20 °C, followed by a rapid decrease, while a moderate increase occurred within 40–60 days at 10 °C. Slight increases were observed in SPS activity within 20 days at 20 °C and 50 days at 10 °C. Enzyme activities remained steady or underwent a small change in canes stored at 2 °C. Enzyme activities were significantly correlated with reducing sugar content.

Chitosan was applied to kamaboko gels made from grass carp (Ctenopharyngodon idellus), and the correlative influences on gelling quality and lipid oxidation were evaluated by color, texture, expressible water, TBA (2-thiobarbituric acid) and peroxide values. Whiteness, hardness, springiness, cohesiveness, chewiness, adhesiveness, TBA value increased, while expressible water and peroxide value decreased when 1% chitosan was added in gels. Addition with 1% chitosan was considered as a promising approach in the processing of grass carp gels to improve thermal gelling properties and delay lipid oxidation.

Harvested cucumber (Cucumis sativus L. cv. Jinyou-1) fruits were placed at 37 °C (pre-warming) or at 20 °C (control) for 24 h prior to be stored at 2 °C for 9 days. After storage, fruits were cut into three sections with equal length, namely top (calyx end), middle and bottom (stalk end), respectively. In order to determine the responses of phospholipase D (PLD) and lipoxygenase (LOX) to chilling stress, their activities and expression pattern of PLD gene in three sections of cucumber fruits were measured when the symptoms of chilling injury first appeared as numerous tiny pits. Chilling injury assessed as chilling injury index and electrolyte leakage occurred initially in the top area near calyx of fruits, and developed toward the bottom near stalk. This spatial development of chilling injury was in parallel with the gradients of PLD and LOX activities and PLD mRNA levels. Alleviation of chilling injury by pre-warming treatment was related with increased content of membrane-associated Ca2+, suppressed expression of PLD mRNA, and reduced activities of PLD and LOX. We suggest that PLD and LOX are associated with the initiation of chilling injury by involving in membrane deterioration and signaling pathway in response to chilling stress.

The gene expression patterns of antioxidative enzymes in cucumber (Cucumis sativus L.) fruits at four different maturity stages, immature (3-8 d after anthesis (DAA), mature (9-16 DAA), breaker (17-22 DAA), and yellow (35-40 DAA), were determined before and after cold storage at 2°C for 9 d and after subsequent rewarming at 20°C for 2 d. The electrolyte leakage and malondialdehyde content in cucumber fruits were increased after cold storage and subsequent rewarming. Increased expressions of peroxidase, ascorbate peroxidase (APX), and monodehydroascorbate reductase after cold storage played an important role in cucumber fruits to cope with chilling injury. The elevated cyt-superoxide dismutase, catalase, APX and dehydroascorbate reductase after subsequent rewarming in cucumber fruits facilitated the recovery from chilling stress. The highest expression levels of all the seven antioxidative enzyme genes in yellow fruits might be responsible for the enhanced chilling tolerance. Cucumber fruits at earlier developmental stages was more susceptible to chilling stress than those at later stages. The relative higher gene expressions of antioxidative enzymes genes at earlier developmental stages may be the responses to the sever oxidative stress caused by chilling injury.

Harvested cucumber (Cucumis sativus L. cv. Jinyou-1) fruit were placed at 37 °C (heat treatment) or at 20 °C (control) for 24 h prior to storage at 2 °C. In order to determine the responses of phospholipase D (PLD) and lipoxygenase (LOX) to chilling stress, their activities and the expression pattern of the PLD gene in cucumber fruit were measured during storage. Chilling injury assessed as electrolyte leakage and malondialdehyde (MDA) content was alleviated by heat treatment. Heated fruit showed reduced activities of LOX and PLD with suppressed expression of PLD mRNA compared with control fruit over the storage. The data indicate that PLD and LOX may be the major lipid-degradative enzymes involved in the induction of chilling injury in cucumber fruit. Our results suggest that PLD and LOX might be associated with the initiation of chilling injury by involvement in membrane deterioration.

•Wounding induces suberin accumulation in kiwifruit.•Abscisic acid (ABA) promots wound-induced suberization in kiwifruit.•ABA stimulates wound suberization likely through activation of PAL, CAD and POD.Wound-induced suberization is an essentially protective healing process for fruit to reduce water loss and avoid infecting. However, cognate mechanisms that regulate this process are little known. To expand our knowledge of suberization induced by wounding, a wound-healing investigation together with metabolite profiling study was conducted in postharvest kiwifruit (Actinidia deliciosa). The development of suberization in wounded fruit was demonstrated by autofluorescence observation and toluidine blue staining at 1–4 day (d) after wounding. Activities of phenylalanine ammonia-lyase (PAL), cinnamyl-alcohol dehydrogenase (CAD) and peroxidase (POD) in wound-healing tissue were enhanced by abscisic acid (ABA). The constituent analysis of suberin including polyphenolics (SPP) and polyaliphatics (SPA) proved that exogenous ABA increased the content levels of total phenols, total flavonoids and alkanes, alkenes, alcohols, alkane acids, olefine acids, esters, glycerides and vitamin E in wound-healing tissue. Results suggested that ABA stimulated suberization through the activation of PAL, CAD and POD to accelerate wound-healing of wounded kiwifruit.