Where systems biology meets postharvest

According to the dictionary, a system is something like “a group or combination of interrelated, interdependent, or interacting elements forming a collective entity”. In postharvest, fresh harvested food crops can be considered isolated small scale systems. Postharvest research aims to understand the quality of these ‘systems’ as influenced by postharvest conditions. The phenotypic quality of horticultural produce is based on genetic traits that are expressed through a cascade of reactions subject to complex regulatory mechanisms and diverse environmental conditions. Ultimately, to fully understand postharvest phenomena, a systemic approach that links genetic and environmental responses and identifies the underlying biological networks is required. Thanks to the development of high throughput omics techniques such system-wide approaches have become a viable option to support traditional postharvest research. This review provides an overview of systems biology and how it can lead postharvest research into a new era.     

Evaluation of a 4‐h static copper sulphate treatment against experimental infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus)

The efficacy of copper sulphate (CuSO₄) against the early stages of an experimental acute infection of Flavobacterium columnare in channel catfish (Ictalurus punctatus) was evaluated. Fish were challenged, by waterborne exposure to F. columnare in an ultra‐low flow‐through water delivery system, and treated with CuSO₄ at 4.2 and 2.1 mg L^?1 at 5.5 h post challenge for 4 h. Bacterial challenged non‐treated fish acted as a positive control and non‐challenged non‐treated fish acted as a negative control. Fish challenged with F. columnare and treated with CuSO₄ at 4.2 and 2.1 mg L^?1 post challenge had mortalities of 6.4% and 18.3%, respectively, compared with the positive control, which had 90.2% mortality. The mortality of challenged fish treated with CuSO₄ at 4.2 and 2.1 mg L^?1 was significantly different from the positive control. There was no significant difference between the mortalities of the 4.2 and 2.1 mg L^?1 treatments. The results suggest that CuSO₄ has clear therapeutic value against columnaris infections.     

THE SCINTIGRAPHIC EVALUATION OF SOLID PHASE GASTRIC EMPTYING IN NORMAL CATS

The gastric emptying half-time of solid food in normal cats was determined using a scintigraphic technique. ^99mTc-sulfur colloid was applied to dry food. Sequential images were acquired post prandial, and the gastric emptying half-time was determined for several different acquisition and processing parameters. Good correlation was found between different acquisition and processing methods, some of which made use of edge detection applications, while others used different views, or number of views from which the gastric emptying half-time was calculated. The mean ± standard deviation, (range) and median of the gastric emptying half-time determined using the geometric mean of total counts in hand-drawn regions of interest from the lateral and ventral images were 2.47 × 0.71, (1.42–3.61) and 2.37 hours respectably.     

Identification of marker alleles linked to fire blight resistance QTLs in apple genotypes

Molecular marker analysis can be an effective tool when searching for new fire blight resistance donors. It can speed up the breeding process as well, even though many of the available markers linked to fire blight resistance QTLs have not yet been tested by screening a large number of cultivars. The aim of this study was to search for alternate sources of the three major QTLs of fire blight resistance; FBF7, FB_MR5 and FB_E, as well as to test the efficiency of some markers linked to minor QTLs. Altogether, nine primer pairs were used on 77 genotypes including new Hungarian cultivars and old apple cultivars from the Carpathian basin. Several marker alleles of FB resistance QTLs have been detected in the screened genotypes, most importantly the alleles coupling with FB_MR5 in the old cultivars ‘Kéresi muskotály’, ‘Szabadkai szercsika’ and ‘Batul’. We propose these cultivars as the first available resistance donors of FB_MR5 instead of the crabapple Malus × robusta 5. The results also bring new information regarding the resistance alleles of new Hungarian cultivars and selections.     

H2O2参与大麦对白粉菌的防卫反应

抗病品种Ｓｕｌｔａｎ－５及其突变体与白粉菌小种Ａ６互作的细胞学研究表明,接种３６ｈ后,抗感品种中白粉菌分生孢子形成附着胞的频率及侵入频率无显著差异。抗病品种比感病品种过敏性反应细胞明显增多,过生反应与Ｍｌａ－１２基因型的大麦品种对白粉菌的小种专化抗性有关,用ＤＡＢ（地氨基联苯胺）观察到Ｈ２Ｏ２在乳突和过敏性反应细胞中积累。接各ｈ后在初生芽管的乳突以及接种１５ｈ后在附着胞下面的乳突有晕圈处有Ｈ２Ｏ２     

Perinatal hypoxia induces subsequent retinal degeneration in the offspring of ovoviviparous fish, Xiphophorous maculates

OBJECTIVE: This experiment evaluated the perinatal hypoxic effect on the retina of offspring of the ovoviviparous fish. ANIMAL STUDIED: The ovoviviparous fish Xiphophorous maculates was used for the experiment. PROCEDURE: The mothers were kept in a hypoxic environment of 3.5% oxygen for 6 h, starting 30 h before hatching. Subsequently, the retinae of the offspring were fixed, sectioned at 6 microm and evaluated microscopically from the age of 1 to 35 days. RESULTS: Degeneration of the outer nuclear layer of the retina was noted on the 3rd day and severe retinal degeneration was observed on the 35th day. Immunocytochemistry confirmed apoptosis by TUNEL reaction. There was no difference in neovascularization, as revealed by vascular endothelial growth factor, between controls (group 1) and hypoxic fish (group 2). CONCLUSIONS: Perinatal hypoxia could have long-lasting effects on the central nervous system in some species.     

Electrophysiological identification of site-insensitive mechanisms in knockdown-resistant strains (kdr,super-kdr) of the housefly larva (Musca domestica)

The effects of pyrethroids were studied upon isolated segmental nerves and neuromuscular junctions in both susceptible (Cooper) and knockdown-resistant (kdr; super-kdr) strains of housefly larvae (Musca domestica L.). Isolated segmental nerves contained neither cell bodies nor synaptic contacts; thus, any effects of pyrethroids were attributed solely to their actions upon voltage-dependent Na⁺ channels. Threshold concentrations of the type II pyrethroid, deltamethrin, required to elevate the spontaneous firing rate of these nerves were determined. Both resistant strains were about ten times less sensitive to deltamethrin than the susceptible strain, but insensitivity of super-kdr nerves was no greater than in the less resistant kdr strain. At neuromuscular junctions, the minimum concentrations of pyrethroids needed to trigger massive increases in the frequency of miniature excitatory postsynaptic potentials (mEPSPs) were determined for deltamethrin and the type I pyrethroid, fenfluthrin. With fenfluthrin there was no detectable difference between the junctions of kdr and super-kdr strains, which were both about ten-fold less sensitive than Cooper junctions. With deltamethrin, kdr junctions were about 30 times less sensitive than those of Cooper; super-kdr junctions were dramatically insensitive to deltamethrin, being some 10000- and 300-fold less sensitive than those of Cooper and kdr respectively. Thus, in the synaptic assay, super-kdr conferred an extension in resistance over kdr only against the type II pyrethroid, it being ineffective against fenfluthrin. We suggest that kdr resistance comprises at least two site-insensitive areas within the nervous system. One involves insensitivity of the Na⁺ channel and has similar efficacy in both kdr and super-kdr strains against type I and II pyrethroids; the other is associated with the presynaptic terminal and is particularly effective in super-kdr resistance against type II pyrethroids. The latter could be associated with Ca²⁺-activated phosphorylation of proteins involved with neurotransmitter release. Such phosphorylation reactions are known to be perturbed by pyrethroids, especially by type II compounds.     

Salmonella enterica serovar Kentucky recovered from human clinical cases in Maryland,USA (2011–2015)

Salmonella Kentucky is among the most frequently isolated S. enterica serovars from food animals in the United States. Recent research on isolates recovered from these animals suggests there may be geographic and host specificity signatures associated with S. Kentucky strains. However, the sources and genomic features of human clinical S. Kentucky isolated in the United States remain poorly described. To investigate the characteristics of clinical S. Kentucky and the possible sources of these infections, the genomes of all S. Kentucky isolates recovered from human clinical cases in the State of Maryland between 2011 and 2015 (n = 12) were sequenced and compared to a database of 525 previously sequenced S. Kentucky genomes representing 12 sequence types (ST) collected from multiple sources on several continents. Of the 12 human clinical S. Kentucky isolates from Maryland, nine were ST198, two were ST152, and one was ST314. Forty‐one per cent of isolates were recovered from patients reporting recent international travel and 58% of isolates encoded genomic characteristics similar to those originating outside of the United States. Of the five isolates not associated with international travel, three encoded antibiotic resistance genes conferring resistance to tetracycline or aminoglycosides, while two others only encoded the cryptic aac(6′)‐Iaa gene. Five isolates recovered from individuals with international travel histories (ST198) and two for which travel was not recorded (ST198) encoded genes conferring resistance to between 4 and 7 classes of antibiotics. Seven ST198 genomes encoded the Salmonella Genomic Island 1 and substitutions in the gyrA and parC genes known to confer resistance to ciprofloxacin. Case report data on food consumption and travel were, for the most part, consistent with the inferred S. Kentucky phylogeny. Results of this study indicate that the majority of S. Kentucky infections in Maryland are caused by ST198 which may originate outside of North America.     

IMAGING DIAGNOSIS—MULTIMODALITY FINDINGS IN AN ADULT DOG WITH PRIMARY SARCOMA OF THE PULMONARY ARTERY AND MYOCARDIAL METASTASES

Intravascular pulmonary artery sarcomas in combination with myocardial metastasis are rare in dogs. We describe the radiographic, echocardiographic, and electrocardiographic‐gated (ECG‐gated) computed tomographic angiography (CTA) findings in a dog with pulmonary artery sarcoma. All imaging studies demonstrated severe main pulmonary artery enlargement. Echocardiography and ECG‐gated CTA revealed a mass occluding the lumen of the right pulmonary artery. In addition, CTA revealed focal left ventricular myocardial contrast enhancement and parenchymal lung changes. Postmortem examination confirmed the presence of a large thrombus associated with arteriosclerosis and an intravascular sarcoma in the right pulmonary artery with metastases to the myocardium, lungs and brain.     

Retrospective analysis of the influence of environmental drivers on commercial stocks and fishing opportunities in the Irish Sea

Irish Sea fisheries have undergone considerable change in recent years following the decline of commercially important finfish stocks and their slow response to management's recovery plans. In 2015, the fishing industry called for a holistic exploration into the impact of environmental change and food web effects to identify the drivers underpinning stock dynamics. In this study, we identify correlations between large‐scale climatic indicators, temperature, primary and secondary productivity, and fish recruitment in the Irish Sea and incorporate them into an Ecopath with Ecosim food web model co‐created by scientists and fishers. Negative correlations were found between the North Atlantic Oscillation winter index (NAOw) and large zooplankton abundance and between the Atlantic Multidecadal Oscillation (AMO) and the recruitment of cod (Gadus morhua) and whiting (Merlangius merlangus). Using correlation analyses to direct the addition of environmental drivers to the Irish Sea ecosystem model improved the models fit against observed biomass and catch data and revealed the indirect impacts of environmental change as mitigated through trophic interactions. Model simulations suggest that historic environmental change suppressed the overall production of commercial finfish, limiting opportunities for the fishing industry, whilst also dampening the rate of stock recovery despite marked reductions in fishing effort. These results suggest that failure to account for ecosystem information may lead to misconceived expectations and flawed fisheries management; therefore, there is a need to operationalize ecosystem information through management procedures to support fisheries advice.