Tools Shape Paradigms of Plant-Environment Interactions

The purpose of this study was to investigate the L. monocytogenes occurrence and genetic diversity in three Belgian pork cutting plants. We specifically aim to identify harborage sites and niche locations where this pathogen might occur. A total of 868 samples were taken from a large diversity of food and non-food contact surfaces after cleaning and disinfection (C&D) and during processing. A total of 13% (110/868) of environmental samples tested positive for L. monocytogenes. When looking in more detail, zone 3 non-food contact surfaces were contaminated more often (26%; 72/278) at typical harborage sites, such as floors, drains, and cleaning materials. Food contact surfaces (zone 1) were less frequently contaminated (6%; 25/436), also after C&D. PFGE analysis exhibited low genetic heterogeneity, revealing 11 assigned clonal complexes (CC), four of which (CC8, CC9, CC31, and CC121) were predominant and widespread. Our data suggest (i) the occasional introduction and repeated contamination and/or (ii) the establishment of some persistent meat-adapted clones in all cutting plants. Further, we highlight the importance of well-designed extensive sampling programs combined with genetic characterization to help these facilities take corrective actions to prevent transfer of this pathogen from the environment to the meat.

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Investigation of the Effectiveness of Disinfectants Used in Meat-Processing Facilities to Control Clostridium sporogenes and Clostridioides difficile Spores

Foods ◽

10.3390/foods10061436 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1436

Author(s):

Siobhán McSharry ◽

Leonard Koolman ◽

Paul Whyte ◽

Declan Bolton

Keyword(s):

Test Tube ◽

Meat Industry ◽

Meat Processing ◽

Clostridium Sporogenes ◽

Safety Issues ◽

Clostridioides Difficile ◽

Plant Environment ◽

D Values ◽

Sulphamic Acid ◽

Spore Forming Bacteria

Spore-forming bacteria are a major concern for the food industry as they cause both spoilage and food safety issues. Moreover, as they are more resistant than vegetative cells, their removal from the food processing environment may be difficult to achieve. This study investigated the efficacy of the ten most commonly used disinfectant agents (assigned 1–10), used at the recommended concentrations in the meat industry, for their ability to eliminate Clostridium sporogenes and Clostridioides difficile spores. Test-tube based suspension assays suggested that disinfectants 2 (10% v/v preparation of a mixture of hydrogen peroxide (10–30%), acetic acid (1–10%) and peracetic acid (1–10%)), 7 (4% w/v preparation of a mixture of peroxymonosulphate (30–50%), sulphamic acid (1–10%) and troclosene sodium (1–10%)) and 10 (2% v/v preparation of a mixture of glutaraldehyde (10–30%), benzalkonium chloride (1–10%)) were the most effective formulations. D-values for these ranged from 2.1 to 8.4 min at 20 °C for the target spores. Based on these findings, it is recommended that these disinfectants are used to control Clostridium spores in the meat plant environment.

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Comparative Quantitative Trait Loci Mapping of Aliphatic, Indolic and Benzylic Glucosinolate Production in Arabidopsis thaliana Leaves and Seeds

Genetics ◽

10.1093/genetics/159.1.359 ◽

2001 ◽

Vol 159 (1) ◽

pp. 359-370 ◽

Cited By ~ 4

Author(s):

Daniel J Kliebenstein ◽

Jonathan Gershenzon ◽

Thomas Mitchell-Olds

Keyword(s):

Arabidopsis Thaliana ◽

Secondary Metabolites ◽

Plant Environment ◽

Aliphatic Glucosinolates ◽

Glucosinolate Concentration ◽

Indolic Glucosinolates ◽

The Individual ◽

Concentration Mapping ◽

Indolic Glucosinolate ◽

Aliphatic Glucosinolate

Abstract Secondary metabolites are a diverse set of plant compounds believed to have numerous functions in plant-environment interactions. Despite this importance, little is known about the regulation of secondary metabolite accumulation. We are studying the regulation of glucosinolates, a large group of secondary metabolites, in Arabidopsis to investigate how secondary metabolism is controlled. We utilized Ler and Cvi, two ecotypes of Arabidopsis that have striking differences in both the types and amounts of glucosinolates that accumulate in the seeds and leaves. QTL analysis identified six loci determining total aliphatic glucosinolate accumulation, six loci controlling total indolic glucosinolate concentration, and three loci regulating benzylic glucosinolate levels. Our results show that two of the loci controlling total aliphatic glucosinolates map to biosynthetic loci that interact epistatically to regulate aliphatic glucosinolate accumulation. In addition to the six loci regulating total indolic glucosinolate concentration, mapping of QTL for the individual indolic glucosinolates identified five additional loci that were specific to subsets of the indolic glucosinolates. These data show that there are a large number of variable loci controlling glucosinolate accumulation in Arabidopsis thaliana.

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Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽

10.1093/aobpla/plaa072 ◽

2021 ◽

Author(s):

Tiphaine Vidal ◽

Hafssa Aissaoui ◽

Sabrina Rehali ◽

Bruno Andrieu

Keyword(s):

Genotypic Variation ◽

Leaf Size ◽

High Rate ◽

Time Interval ◽

Extension Rate ◽

Leaf Production ◽

Maize Cultivars ◽

Plant Environment ◽

The Difference ◽

Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

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