Application of Gum Arabic as Edible Coating for Improving Postharvest Quality of Potato Tubers

Hydrocolloid gums are extensively used in food industry. Recently hydrocolloid gums especially Gum Arabic (GA) has been widely used as edible coatings to extent shelf life of postharvest fruits and vegetables. The objective of this study was to evaluate the effect of GA edible film application mixed with glycerol and CaCl2as base matrix with all GA films i.e. GA/EDTA,GA/L. paracasei supernatant and GA/EDTA /L. paracasei supernatant in preservation of potato tubers stored at 8°C and 30±5°C for 35 days. Physicochemical analyses including pH, weight loss percentage and total soluble solids percentage (TSS), as well as microbial analysis (total counts of bacteria, mold and yeast and Enterobacteriaceae).The obtained result revealed that the total microbial count was found that GA/EDTA/ L. paracasei supernatant gave a very close results to petroleum coating (wax) and the best results compared withnoncoated (control) tubers, this was evident through the lower microbial load, better results than other treatments and noncoated tubers such as reducing weight loss, total soluble solids, better control on pH and expansion of the shelf life

Oncogenic challenge of bromocriptine and L-arginine versus conventional antidiabetics on diethyl nitrosamine-induced liver tumorigenesis in diabetic rats: focus on AMPK activation

Background: Diabetes mellitus (DM) is associated with a spectrum of cancers where the metabolic antecedents, consequences, and therapy might affect cancer risk. The association between hepatocellular carcinoma (HCC) and DM had been confirmed. Approaches to HCC prevention focus on the molecular regulators of the disease process defined as the inflammation-fibrosis-cancer axis. The AMP-activated protein kinase (AMPK) is an interesting metabolic tumor suppressor and a promising target for cancer prevention and therapy. This study aimed to investigate the effects of bromocriptine mesylate and L-arginine on hepatic carcinogenesis on a rat model of hepatic neoplasia induced by diethyl nitrosamine (DENA) and promoted by type-2 DM in contrast to the conventional antidiabetics.Methods: One hundred male Wistar rats were randomly assigned into two sets; control set (normal, HCC, DM, and combined HCC/DM) and treated set where rats received one of the following drugs for another 5 weeks: insulin glargine, glimepiride, metformin, pioglitazone, bromocriptine mesylate, or L-arginine. Bodyweight changes, blood glucose level, liver functions tests, serum C-peptide and alpha-fetoprotein (AFP), and hepatic activated AMPK were assessed beside the hepatic histopathological changes.Results: Equivalent to metformin, bromocriptine and L-arginine treatment significantly reduced AFP, despite their minor glycemic control. L-arginine induced AMPK activation, yet less than metformin. Histopathologic examination revealed a reduction in hepatic intra-lobular chronic inflammatory cell infiltration, steatosis and necrosis by metformin, bromocriptine, and L-arginine. Hepatic necro-inflammatory changes were most prominent in insulin-treated rats.Conclusions: L-arginine and bromocriptine mesylate prevent early neoplastic changes almost equivalent to metformin at least partially via hepatic AMPK activation

Phylogenetic analysis of 23S rRNA gene sequences of some Rhizobium leguminosarum isolates and their tolerance to drought

The phylogenetic relationships among thirteen Rhizobium leguminosarum bv. viciae isolates collected from various geographical regions were studied by analysis of the 23S rRNA sequences. The average of genetic distance among the studied isolates was very narrow (ranged from 0.00 to 0.04) and the studied isolates formed two main groups based on cluster analysis. The isolates were tested for their growth on YMA medium supplemented with concentrations 10, 20 and 30% of polyethylene glycol plus control. All isolates exhibited good drought-tolerant efficiencies at 10% PEG. While most of the isolates could not tolerate up to 20% PEG, isolates of Rlv6, Rlv9, Rlv12 and Rlv13 tolerated up to 20% PEG.Keywords: Rhizobium leguminosarum, 23S rRNA gene, phylogenetic tree, diversity and drought toleranc

Field Crop Responses and Management Strategies to Mitigate Soil Salinity in Modern Agriculture: A Review

The productivity of cereal crops under salt stress limits sustainable food production and food security. Barley followed by sorghum better adapts to salinity stress, while wheat and maize are moderately adapted. However, rice is a salt-sensitive crop, and its growth and grain yield are significantly impacted by salinity stress. High soil salinity can reduce water uptake, create osmotic stress in plants and, consequently, oxidative stress. Crops have evolved different tolerance mechanisms, particularly cereals, to mitigate the stressful conditions, i.e., effluxing excessive sodium (Na+) or compartmentalizing Na+ to vacuoles. Likewise, plants activate an antioxidant defense system to detoxify apoplastic cell wall acidification and reactive oxygen species (ROS). Understanding the response of field crops to salinity stress, including their resistance mechanisms, can help breed adapted varieties with high productivity under unfavourable environmental factors. In contrast, the primary stages of seed germination are more critical to osmotic stress than the vegetative stages. However, salinity stress at the reproductive stage can also decrease crop productivity. Biotechnology approaches are being used to accelerate the development of salt-adapted crops. In addition, hormones and osmolytes application can mitigate the toxicity impact of salts in cereal crops. Therefore, we review the salinity on cereal crops physiology and production, the management strategies to cope with the harmful negative effect on cereal crops physiology and production of salt stress

Plants take action to mitigate salt stress: Ask microbe for help, phytohormones, and genetic approaches

Global agriculture is a pivotal activity performed by various communities worldwide to produce essential human food needs. Plant productivity is limited by several factors, such as salinity, water scarcity, and heat stress. Salinity significantly causes short or long-term impacts on the plant photosynthesis mechanisms by reducing the photosynthetic rate of CO2 assimilation and limiting the stomatal conductance. Moreover, disturbing the plant water status imbalance causes plant growth inhibition. Up-regulation of several plant phytohormones occurs in response to increasing soil salt concentration. In addition, there are different physiological and biochemical mechanisms of salt tolerance, including ion transport, uptake, homeostasis, synthesis of antioxidant enzymes, and osmoprotectants. Besides that, microorganisms proved their ability to increase plant tolerance, Bacillus spp. represents the dominant bacteria of the rhizosphere zone, characterised as harmless microbes with extraordinary abilities to synthesise many chemical compounds to support plants in confronting salinity stress. In addition, applying arbuscular mycorrhizal fungi (AMF) is a promising method to decrease salinity-induced plant damage as it could enhance the growth rate relative to water content. In addition, there is a demand to search for new salt-tolerant crops with more yield and adaptation to unfavourable environmental conditions. The negative impact of salinity on plant growth and productivity, photosynthesis, stomatal conductance, and changes in plant phytohormones biosynthesis, including abscisic acid and salicylic acid, jasmonic acid, ethylene, cytokinins, gibberellins, and brassinosteroids was discussed in this review. The mechanisms evolved to adapt and/or survive the plants, including ion homeostasis, antioxidants, and osmoprotectants biosynthesis, and the microbial mitigate salt stress. In addition, there are modern approaches to apply innovative methods to modify plants to tolerate salinity, especially in the essential crops producing probable yield with a notable result for further optimisation and investigations