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Grapevine (Vitis vinifera L.) crops are continuously exposed to biotic and abiotic stresses, which can cause genetic and epigenetic alterations. To determine the possible effects of grapevine cryopreservation on the regulation of DNA demethylase genes, this work studied the expression of DNA demethylase genes in cryopreserved and post-cryopreserved grapevine tissues. V. vinifera DNA demethylases were characterized by in silico analysis, and gene expression quantification was conducted by RT‒qPCR. Three DNA demethylase sequences were found: VIT_13s0074g00450 (VvDMT), VIT_08s0007g03920 (VvROS1), and VIT_06s0061g01270 (VvDML3). Phylogenetic analysis revealed that the sequences from V. vinifera and A. thaliana had a common ancestry. In the promoters of responsive elements to transcription factors such as AP-2, Myb, bZIP, TBP, and GATA, the conserved domains RRM DME and Perm CXXC were detected. These responsive elements play roles in the response to abiotic stress and the regulation of cell growth. These data helped us characterize the V. vinifera DNA demethylase genes. Gene expression analysis indicated that plant vitrification solution 2 (PVS2) treatment does not alter the expression of DNA demethylase genes. The expression levels of VvDMT and VvROS1 increased in response to cryopreservation by vitrification. Furthermore, in post-cryopreservation, VvROS1 was highly induced, and VvDML3 was repressed in all the treatment groups. Gene expression differences between different treatments and tissues may play roles in controlling methylation patterns during gene regulation in tissues stressed by cryopreservation procedures and in the post-cryopreservation period during plant growth and development.

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The effect of individual and combined supplementation of FA and GPM on physiological variables, productive performance, and carcass characteristics of finishing pigs under heat stress conditions were investigated. Forty Yorkshire × Duroc pigs (80.23 kg) were individually housed and randomly distributed into 4 groups under a 2 × 2 factorial arrangement (n = 10): Control (basal diet, BD); FA, BD + 25 mg FA; GPM, BD with 2.5% GPM; and MIX, BD with 25 mg FA and 2.5% GPM. Additives were supplemented for 31 days. The inclusion of FA or GPM did not modify rectal temperature and respiratory rate. There was an effect of the interaction on FI, which increased when only GPM was supplemented, with respect to Control and MIX (p < 0.05). Average daily gain (ADG) and feed conversion (FC) were not affected by treatments (p > 0.05). The inclusion of FA improved hot and cold carcass weight, while the addition of GPM decreased the marbling (p < 0.05) and tended to increase loin area (p < 0.10). GPM increased liver weight (p < 0.05). The addition of GPM and FA can improve some carcass characteristics under heat stress conditions. It is necessary to continue investigating different levels of inclusion of GPM and FA in finishing pigs' diets.

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In Mexico, the mango crop is affected by anthracnose caused by Colletotrichum species. In the search for environmentally friendly fungicides, chitosan has shown antifungal activity. Therefore, fungal isolates were obtained from plant tissue with anthracnose symptoms from the state of Guerrero in Mexico and identified with the ITS and ß-Tub2 genetic markers. Isolates of the Colletotrichum gloeosporioides complex were again identified with the markers ITS, Act, ß-Tub2, GADPH, CHS-1, CaM, and ApMat. Commercial chitosan (Aldrich, lot # STBF3282V) was characterized, and its antifungal activity was evaluated on the radial growth of the fungal isolates. The isolated anthracnose-causing species were C. chrysophilum, C. fructicola, C. siamense, and C. musae. Other fungi found were Alternaria sp., Alternaria tenuissima, Fusarium sp., Pestalotiopsis sp., Curvularia lunata, Diaporthe pseudomangiferae, and Epicoccum nigrum. Chitosan showed 78% deacetylation degree and a molecular weight of 32 kDa. Most of the Colletotrichum species and the other identified fungi were susceptible to 1 g L-1 chitosan. However, two C. fructicola isolates were less susceptible to chitosan. Although chitosan has antifungal activity, the interactions between species of the Colletotrichum gloeosporioides complex and their effect on chitosan susceptibility should be studied based on genomic changes with molecular evidence.

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Wheat is a highly relevant crop worldwide, and like other massive crops, it is susceptible to foliar diseases, which can cause devastating losses. The current strategies to counteract wheat diseases include global monitoring of pathogens, developing resistant genetic varieties, and agrochemical applications upon diseases' appearance. However, the suitability of these strategies is far from permanent, so other alternatives based on the stimulation of the plants' systemic responses are being explored. Plants' defense mechanisms can be elicited in response to the perception of molecules mimicking the signals triggered upon the attack of phytopathogens, such as the release of plant and fungal cell wall-derived oligomers, including pectin and chitin derivatives, respectively. Among the most studied cell wall-derived bioelicitors, oligogalacturonides and oligochitosans have received considerable attention in recent years due to their ability to trigger defense responses and enhance the synthesis of antipathogenic compounds in plants. Particularly, in wheat, the application of bioelicitors induces lignification and accumulation of polyphenolic compounds and increases the gene expression of pathogenesis-related proteins, which together reduce the severity of fungal infections. Therefore, exploring the use of cell wall-derived elicitors, known as oligosaccharins, stands as an attractive option for the management of crop diseases by improving plant readiness for responding promptly to potential infections. This review explores the potential of plant- and fungal-derived oligosaccharins as a practical means to be implemented in wheat crops.

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The main goal of this study was to evaluate the inhibition of Pseudomonas aeruginosa virulence factors and Quorum Sensing during exposure to carvacrol. P. aeruginosa (ATCC 10154) was exposed to carvacrol determining changes in biofilm development, motility, acyl-homoserine lactones (AHL) synthesis and relative expression of lasI/lasR. Docking analysis was used to determinate interactions between carvacrol with LasI and LasR proteins. P. aeruginosa produced 60% lower AHLs when exposed to carvacrol (1.9 mM) compared to control, without affecting cellular viability, indicating a reduction on the LasI synthase activity. AHL-C12, C6, and C4 were detected and related to biofilm development, motility, and pyocyanin production, respectively. The presence of carvacrol reduced the expression of lasR, without affecting lasI gen. Moreover, computational docking showed interactions of carvacrol with amino acids in the active site pocket of LasI (-5.6 kcal mol-1) and within the binding pocket of LasR (-6.7 kcal mol-1) of P. aeruginosa. These results demonstrated that virulence of P. aeruginosa was reduced by carvacrol, by inhibiting LasI activity with the concomitant reduction on the expression of lasR, biofilm and swarming motility. This study provides relevant information about the effect of carvacrol against quorum sensing to inhibit virulence factors of P. aeruginosa at enzymatic and gene levels. These findings can contribute to the development of natural anti-QS products, which can affect pathogenesis.

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BACKGROUND: Grapes grown in warm weather do not develop a desirable red color and require the use of products to enhance berry color. Pectin-derived oligosaccharides (PDOs) have been shown to have a role in various responses including plant defense, growth and development. In this work a mixture of PDOs with 3-20 degrees of polymerization was applied to Vitis vinifera cv. Flame Seedless grapes under field conditions and compared to the effects of ethephon (an ethylene-releasing compound). The effect of treatments on grape color, anthocyanin content and phenylalanine ammonia lyase (PAL) mRNA levels was evaluated. RESULTS: PDOs treatment increased berry color measured by the Color Index of Red Grapes (CIRG) and anthocyanin content, compared to ethephon and untreated berries (control); 1.5, 1 and 0.5 mg mL⁻¹ PDOs increased berry color by 30%, 27% and 26%, respectively, when compared to control berries. Levels of PAL mRNA accumulating in berries treated with PDOs were elevated within the first 24 h of treatment. CONCLUSIONS: PDOs enhanced the color and anthocyanin content of Flame Seedless grape berries possibly due by the induction of PAL mRNA expression. The results demonstrated that PDOs can be used to improve fruit quality aspects such as berry skin color.

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Four polymethoxylated flavones (3,5,6,7,3',4'-hexamethoxyflavone, 3,5,6,7,8,3',4'-heptamethoxyflavone, 5,6,7,8,4'-pentamethoxyflavone and 5,6,7,8,3',4'-hexamethoxyflavone) were isolated and characterized from cold-pressed orange oil. Their antifungal activities were evaluated against Colletotrichum gloeosporioides (Penz) Penz & Sacc, a major plant pathogen of fruits that causes significant damage to crops in tropical, sub-tropical and temperate regions. Methoxylated flavones were effective in inhibiting mycelial growth of the fungus. As flavone concentration increased, mycelial growth decreased. 5,6,7,8,3',4'-Hexamethoxyflavone completely inhibited the growth of Cgloeosporioides at a concentration of 100 microg ml(-1).

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