Plant parasitic nematodes are a major problem for growers worldwide, causing severe crop losses. Several conventional strategies, such as chemical nematicides and biofumigation, have been employed in the past to manage their infection in plants and spread in soils. However, the search for the most sustainable and environmentally safe practices is still ongoing. This review summarises information on plant parasitic nematodes, their distribution, and their interaction with their host plants, along with various approaches to manage their infestations. It also focuses on the application of microbial and fermentation-based bionematicides that have not only been successful in controlling nematode infection but have also led to plant growth promotion and proven to be environmentally safe. Studies with new information on the relative abundance of plant parasitic nematodes in two agricultural sites in the Republic of Ireland are also reported. This review, with the information it provides, will help to generate an up-to-date knowledge base on plant parasitic nematodes and their management practices.
Deoxynivalenol (DON) and Zearalenone (ZEN) are two commonly co-occurring mycotoxins produced by members of the genus Fusarium. As important food chain contaminants, these can adversely affect both human and animal health. Critically, as they are formed prior to harvesting, their occurrence cannot be eliminated during food production, leading to ongoing contamination challenges. DON is one of the most commonly occurring mycotoxins and is found as a contaminant of cereal grains that are consumed by humans and animals. Consumption of DON-contaminated feed can result in vomiting, diarrhoea, refusal of feed, and reduced weight gain in animals. ZEN is an oestrogenic mycotoxin that has been shown to have a negative effect on the reproductive function of animals. Individually, their mode of action and impacts have been well-studied; however, their co-occurrence is less well understood. This common co-occurrence of DON and ZEN makes it a critical issue for the Agri-Food industry, with a fundamental understanding required to develop mitigation strategies. To address this issue, in this targeted review, we appraise what is known of the mechanisms of action of DON and ZEN with particular attention to studies that have assessed their toxic effects when present together. We demonstrate that parameters that impact toxicity include species and cell type, relative concentration, exposure time and administration methods, and we highlight additional research required to further elucidate mechanisms of action and mitigation strategies.
Background/Objectives: Zinc, an important trace metal, requires daily intake but dietary antagonists including phytic acid reduce its absorption. It is unclear if phytic acid affects zinc absorption at the level of bioaccessibility (how much soluble zinc is available from digestion) or bioavailability (how much zinc is absorbed by the intestine). This study investigates at which level this occurs at and if the zinc source alters the response. Methods: Following a standardised in vitro digestion (INFOGEST), the yield of soluble zinc was measured as the bioaccessible fraction from inorganic and chelated zinc sources, with and without phytic acid. Bioavailability was assessed by measuring cellular zinc uptake in intestinal cell lines (Caco-2 and IPEC-J2). Results: Phytic acid affected the bioaccessibility of zinc, with varying impacts depending on the zinc source. Zinc proteinate had the highest bioaccessibility (42%) without phytic acid, while inorganic zinc sulphate (24%) and zinc bisglycinate (27%) were lower. ZnSO4 was more susceptible to phytic acid antagonism than chelated zinc sources (from 2:100 molar ratio of phytic acid: zinc), while the chelated zinc sources were only affected at a molar ratio of 4:100, with zinc bisglycinate being more susceptible than zinc proteinate. Cellular zinc uptake (bioavailability) and toxicity at equimolar concentrations were unaffected by phytic acid. Conclusions: This study found that phytic acid affected bioaccessibility, not bioavailability. The zinc source impacts the response. Zinc proteinate was consistently more bioaccessible while both chelated zinc sources were less susceptible to phytic acid than inorganic zinc.
In piglets, it is observed that early weaning can lead to poor weight gain due to an underdeveloped gastrointestinal (GI) tract, which is unsuitable for an efficient absorption of nutrients. Short-chain fatty acids (SCFAs) such as butyrate have demonstrated their ability to improve intestinal development by increasing cell proliferation, which is vital during this transition period when the small and large intestinal tracts are rapidly growing. Previous reports on butyrate inclusion in feed demonstrated significantly increased feed intakes (FIs) and average daily gains (ADGs) during piglet weaning. Similar benefits in piglet performance have been observed with the inclusion of yeast cell wall in diets. A proprietary mix of yeast cell wall, SCFAs, and zinc proteinate (YSM) was assessed here in vitro to determine its impact on cellular growth, metabolism and appetite-associated hormones in ex vivo small intestinal pig cells and STC-1 mouse intestinal neuroendocrine cells. Intestinal cells demonstrated greater cell densities with the addition of YSM (150 ppm) compared to the control and butyrate (150 ppm) at 24 h. This coincided with the higher utilisation of both protein and glucose from the media of intestinal cells receiving YSM. Ghrelin (an appetite-inducing hormone) demonstrated elevated levels in the YSM-treated cells on a protein and gene expression level compared to the cells receiving butyrate and the control, while satiety hormone peptide YY protein levels were lower in the cells receiving YSM compared to the control and butyrate-treated cells across each time point. Higher levels of ghrelin and lower PYY secretion in cells receiving YSM may drive the uptake of protein and glucose, which is potentially facilitated by elevated gene transporters for protein and glucose. Greater ghrelin levels observed with the inclusion of YSM may contribute to higher cell densities that could support pig performance to a greater extent than butyrate alone.
8 February 2021 in In Vitro Cellular & Developmental Biology - Animal