Chilling Injury Disorders Research Articles

The Impact of Rootstock on "Big Top" Nectarine Postharvest Concerning Chilling Injury, Biochemical and Molecular Parameters.

Peaches and nectarines have a short shelf life even when harvested at appropriate physiological maturity. Market life is increased by storage at low temperatures. However, chilling injury symptoms can appear, causing physiological disorders and limiting shipping potential. The rootstock effect on the post-harvest quality has hardly been explored. Thus, the principal aim of this work was to study the influence of seven different Prunus rootstocks on the "Big Top" nectarine cv, considering harvest and post-harvest quality parameters and their correlation with chilling injury disorders. Basic fruit quality traits, individual sugars and organic acids analyzed by HPLC and other biochemical compounds such as relative antioxidant capacity, total phenolics content, flavonoids, anthocyanins, vitamin C and related enzyme activities (PAL, POD, PPO) were considered. In addition, correlations with possible candidate genes for chilling injury (CI) tolerance were searched by qPCR. Although a low susceptibility to CI symptoms has been found in "Big Top", rootstocks "PADAC 9902-01", "PADAC 99-05" and "ReplantPAC" exhibited lower CI symptoms. A statistically significant influence of the evaluated rootstocks was found concerning the parameters of this study. Phenols and anthocyanins seem to be important parameters to be considered in the prevention of chilling injury disorders. Moreover, PAL1, PPO4, PG2 and LDOX genes relative expressions were positively associated with chilling injury susceptibility. This study opens new perspectives for understanding peach fruit adaptation and response to cold storage temperatures during the post-harvest period.

Transcriptome and metabolic survey disclose the mode of action of static and dynamic low oxygen postharvest storage strategies to prevent the onset of superficial scald disorder in fruit of ‘Granny Smith’ apple cultivar

To preserve quality features and ensuring availability of fresh fruit on the market, apples need to be stored after harvest. The low temperature applied during storage, beside avoiding important fruit loss, can also promote the development of serious chilling injury disorders, such as superficial scald. One of the strategies largely employed to prevent the development of this phenomenon is the control of the storage atmosphere by lowering down the oxygen concentration. In this work, a multifaceted survey was carried out to investigate transcriptome variation together with three categories of metabolites (phenolics, lipids and volatile organic compounds ) in fruit of ‘Granny Smith’ apple cultivar stored in both static and dynamic controlled hypoxia atmosphere for five and seven months, respectively. The global transcriptome survey identified a core set of differentially expressed genes in three main functional groups, revealing as the duration of storage had an important effect in the coordination of gene expression. The effect of the length of storage was furthermore highlighted by the DEG-network analysis that identified a distinct number and type of transcriptomic hubs. Samples characterized by the development of superficial scald were distinguished by a higher concentration of chlorogenic acid and a higher expression of phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) in a time-dependent fashion. The prevention of this disorder was instead related to distinctive re-programming events, involving the accumulation of specific antioxidant types of metabolites, very long chain fatty acids (VLCFAs) and the expression of genes coordinating a hypoxia acclimation process, such as RAP2-like and plant cysteine oxidase (PCO).

Comparative transcriptome and metabolite survey reveal key pathways involved in the control of the chilling injury disorder superficial scald in two apple cultivars, 'Granny Smith' and 'Ladina'.

The low temperature normally applied to prevent fruit decay during the storage of apples, can also triggers the onset of a chilling injury disorder known as superficial scald. In this work, the etiology of this disorder and the mechanism of action of two preventing strategies, such as the application of 1-MCP (1-methylcyclopropene) and storage at low oxygen concentration in 'Granny Smith' and 'Ladina' apple cultivars were investigated. The metabolite assessment highlighted a reorganization of specific metabolites, in particular flavan-3-ols and unsaturated fatty acids, while the genome-wide transcriptomic analysis grouped the DEGs into four functional clusters. The KEGG pathway and GO enrichment analysis, together with the gene-metabolite interactome, showed that the treatment with 1-MCP prevented the development of superficial scald by actively promoting the production of unsaturated fatty acids, especially in 'Granny Smith'. 'Ladina', more susceptible to superficial scald and less responsive to the preventing strategies, was instead characterized by a higher accumulation of very long chain fatty acids. Storage at low oxygen concentration stimulated a higher accumulation of ethanol and acetaldehyde together with the expression of genes involved in anaerobic respiration, such as malate, alcohol dehydrogenase and pyruvate decarboxylase in both cultivars. Low oxygen concentration, likewise 1-MCP, through a direct control on ethylene prevented the onset of superficial scald repressing the expression of PPO, a gene encoding for the polyphenol oxidase enzyme responsible of the oxidation of chlorogenic acid. Moreover, in 'Granny Smith' apple, the expression of three members of the VII subgroups of ERF genes, encoding for elements coordinating the acclimation process to hypoxia in plants was observed. The global RNA-Seq pattern also elucidated a specific transcriptomic signature between the two cultivars, disclosing the effect of the different genetic background in the control of this disorder.

Lipid peroxidation and lipid-soluble antioxidants as quality control markers in cold-stored fruit for establishing commercial acceptability in Bacon avocados

Avocados are prone to chilling injury disorders when stored at low temperatures. Although most studies have been performed in the worldwide distributed ‘Hass’ variety, other less exploited commercial varieties such as ‘Bacon’ might be more cold-tolerant. Aiming at evaluating how cold storage influences chilling injury, the extent of lipid peroxidation and the contents of lipophilic antioxidants were measured in ‘Bacon’ avocados. Harvested fruit were divided into two groups: one stored for 6 weeks at 4 °C and sampled at various time intervals for 42 days, and the other maintained at low temperatures for 3 and 6 weeks and then exposed to room temperature for 5 days until ripened. Long-term cold storage negatively influenced tocochromanols and carotenoids composition in unripen fruit, decreasing progressively both vitamin E and plastochromanol-8 contents, and most particularly carotenoids; yet chilling injury was prevented during cold storage for 6 weeks. When these fruits were ripened at room temperature, chilling injury increased 20% in the peel but only 5% in the mesocarp (edible part). Enhanced chilling injury in the mesocarp was associated with a 2.3-fold increase in lipid hydroperoxides (a primary lipid peroxidation product) and a 2.5-fold increase in plastochromanol-8 content, while contents of other tocochromanols, carotenoids and malondialdehyde (a secondary product of lipid peroxidation) kept unaltered. Interestingly, medium-term cold storage (3 weeks at 4 °C) did not lead to chilling injury in ripe fruit, therefore cold storage for 3 weeks is considered optimal to prevent large antioxidant vitamin degradation and maintain fruit quality in ripen avocados. In conclusion, despite the high cold tolerance shown by ‘Bacon’ avocados, fruit showed a strong depletion (60%) in carotenoids content after 6 weeks of storage at 4 °C, negatively affecting their commercial acceptability. Aside from evaluating visual chilling injury symptoms, evaluation of lipid peroxidation markers and contents of lipid-soluble antioxidants are deemed to be essential to establish commercial acceptability in cold-stored fruit.

Preservation treatment with methyl jasmonate alleviates chilling injury disorder in pear fruit by regulating antioxidant system and energy status

Preservation treatment with methyl jasmonate alleviates chilling injury disorder in pear fruit by regulating antioxidant system and energy status

Transcriptional analysis of the response of nectarine fruit to low-temperature stress in cold storage

ABSTRACT Nectarine (Prunus persica var. nectarina) is a sub-tropical fruit tree with strong cold sensitivity. In this study, flesh of nectarine (Shuguang) was used to determine the difference in transcriptional data before and after chilling injury under storage. In addition, genes responses involved in nectarine acclimation to cold stress were also explored. Results of the current study showed that nectarine was found to be more susceptible to chilling injury during storage at 5°C than at 0°C, and differentially expressed genes (DEGs) were concentrated in the late stage of low-temperature storage where chilling injury symptoms appeared at the end of the experiment. The key genes related to low-temperature response were associated with post-harvest biological processes. DEGs were annotated on the metabolic pathways of cold regulation signal transduction, cold resistance physiological metabolism and cold resistance-related protein synthesis. Moreover, the expression of genes related to cold stress such as plant hormone signal transduction element such as Auxin-responsive protein, transcription factors responding to cold stress such as WRKY transcription factor and genes related to maintaining membrane stability and regulating physiological metabolism such as proline dehydrogenase was more pronounced when nectarine was stored at 5°C than at 0°C. Overall, these findings showed that alteration in chilling temperature has substantial impact on the transcription levels associated with cold resistance pathway during the low-temperature storage of nectarine and thus promotes chilling injury disorders in nectarine.

Comparison of a dual-laser and a Vis-NIR spectroscopy system for detection of chilling injury in kiwifruit

A novel dual-laser system with laser wavelengths of 730 nm and 850 nm has been developed for the non-destructive detection of chilling injury in Actinidia chinensis var. chinensis ‘Zesy002’ kiwifruit. Chilling injury in kiwifruit is a physiological disorder that may occur during low-temperature storage, with symptoms that are often not evident until the fruit is cut open. This study involved a sample of 162 kiwifruit with differing severity of chilling injury, and a performance comparison between the novel dual-laser system and a standard visible – near infrared (Vis-NIR) interactance spectroscopy approach proven in a prior study. The dual-laser system involved scanning the laser beams across the fruit to generate spatial profiles of light transmission in the fruit. Data analysis with supervised model training, using a support vector machine algorithm, was successfully used to achieve cross-validation prediction accuracies higher than 90 % for distinguishing sound and chilling-injured kiwifruit. The performance was equivalent to that achieved by the Vis-NIR interactance spectroscopy approach, suggesting that the dual-laser method is an alternative and more attractive option because of its easier system layout for high-speed on-line sorting of kiwifruit for chilling injury disorder.

Physicochemical changes and chilling injury disorders in 'Tango' mandarins stored at low temperatures.

The susceptibility to chilling injury and quality changes of 'Tango' mandarins stored at different temperatures was evaluated in fruit grown at two locations in Andalusia (Spain) and grafted on Carrizo Citrange or FA5 rootstock. The peel disorders were also characterized by a microstructural study. Fruit developed chilling injuries, manifested as pitting lesions affecting the equatorial area of the fruit stored at 1 °C or 5 °C; fruit growing on FA5 rootstock showed a slightly lower incidence. The microstructural study revealed that only the upper layers of flavedo were affected in the damaged fruit, the epidermal and hypodermal tissues being dramatically collapsed. Although the fruit was prone to accumulate ethanol, especially after the shelf life that followed the different periods of cold storage, the ethanol did not compromise the overall flavor. Storage of 'Tango' fruit was limited by chilling injuries when stored at 1 °C or 5 °C for more than 20 days. Moreover, at these temperatures, the fruit was prone to accumulate ethanol and develop off flavors. At 9° C, the fruit could be stored for 30 days without compromising external or internal quality. Growing location and rootstock influenced some quality attributes at harvest but not during storage. © 2020 Society of Chemical Industry.

High-density genetic map and QTL analysis of soluble solid content, maturity date, and mealiness in peach using genotyping by sequencing

Peach (Prunus persica) is one of the most important temperate fruit trees in the world, based on its production and cultivated area. Consumer acceptance is the principal objective of multiple breeding programs and it is dependent on many factors. Among these factors, an important role is played by the soluble solids content (SSC) and the postharvest performance represented by mealiness (M) susceptibility as a chilling injury disorder. Additionally, a major maturity date (MD) QTL has been reported to have a pleiotropic effect on both M and SSC. The aim of this work was QTL identification of SSC, MD, and M and to identify adequate candidate genes that are linked to regulation of these traits. The analysis was performed by evaluation of fruit quality traits during three consecutive seasons in an F1 progeny of 194 siblings, which were obtained from the intraspecific cross between the yellow-flesh peach “O’Henry” and the white-flesh nectarine NR-053. The main result was the construction of a genetic linkage map with 499 markers (486 SNPs, 11 SSRs, and two morphological markers) spanning 717.6 cM, with an average distance between markers of 1.5 cM/cluster. The analysis allowed the identification of consistent QTLs for SSC and M in the linkage group LG5 and for MD in LG1, LG2, LG5, and LG6. A large number of genes were annotated in QTL intervals, which was reduced by selecting the genes with at least one SNP, which caused an amino acid variation. For SSC, the data identified four transcription factors, one gene involved directly with the sugar accumulation process, and one cell wall remodeling-related gene. For MD, 23 cell wall-related genes, three jasmonic acid-linked genes, eight transcription factors, and one ripening-related gene were identified. Finally, only one cell wall gene was identified that was associated with M. In conclusion, these results improve our understanding of the genetic control of fruit quality traits with commercial relevance in P. persica and specifically in the O × N mapping population.

1-Methylcyclopropene reduces chilling injury of harvested okra (Hibiscus esculentus L.) pods

Experiments were conducted to investigate the effects of 1-methylcyclopropene (1-MCP) on chilling injury disorders and quality maintenance of harvested okra (Hibiscus esculentus L.) fruit during storage at low temperature. Okra fruit were treated with 1 or 5μlL−1 1-MCP for 16h before storage for 18d at 7°C. Application of 1-MCP significantly alleviated the development of chilling injury disorders such as browning and pitting in okra pods in a concentration-dependent pattern, which was associated with lower membrane permeability and lipid peroxidation. In addition, 1-MCP treatment inhibited the decreases in color parameters (hue angle, lightness and chroma) and chlorophyll degradation, indicating that the bright green color in 1-MCP-treated fruit was well maintained. Furthermore, 1-MCP reduced the chilling-induced decline in variable:maximal chlorophyll fluorescence (Fv/Fm), an indicator of stress injury in plant tissues. Moreover, significantly lower respiration rate in 1-MCP-treated okra was also observed than in control fruit. Overall, 1-MCP treatment showed great potential to reduce the development of chilling injury disorders and maintain fruit quality, which may be a promising technique to extend the storage life of okra pods at low temperature.

Peroxidase activity in avocado fruit stored at chilling temperatures

No increase in peroxidase activity was observed in ‘Fuerte’ avocado fruits which showed chilling injury symptoms as a result of storage at 0 or 2°C. Peroxidase activity in the fruit declined along with fruit softening during the ripening process. It is suggested that peroxidase acitivity in avocado fruit mesocarp has no role in the development of the chilling injury disorder appearing as dark patches on the skin of the fruit.