Camilo Elber Vital

Differences in beef quality between Angus (Bos taurus taurus) and Nellore (Bos taurus indicus) Cattle through a proteomic and phosphoproteomic approach

Proteins are the major constituents of muscle and are key molecules regulating the metabolic changes during conversion of muscle to meat. Brazil is one of the largest exporters of beef and most Brazilian cattle are composed by zebu (Nellore) genotype. Bos indicus beef is generally leaner and tougher than Bos taurus such as Angus. The aim of this study was to compare the muscle proteomic and phosphoproteomic profile of Angus and Nellore. Seven animals of each breed previously subjected the same growth management were confined for 84 days. Proteins were extracted from Longissimus lumborum samples collected immediately after slaughter and separated by two-dimensional electrophoresis. Pro-Q Diamond stain was used in phosphoproteomics. Proteins identification was performed using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Tropomyosin alpha-1 chain, troponin-T, myosin light chain-1 fragment, cytoplasmic malate dehydrogenase, alpha-enolase and 78 kDa glucose-regulated protein were more abundant in Nellore, while myosin light chain 3, prohibitin, mitochondrial stress-70 protein and heat shock 70 kDa protein 6 were more abundant in Angus (P<0.05). Nellore had higher phosphorylation of myosin regulatory light chain-2, alpha actin-1, triosephosphate isomerase and 14-3-3 protein epsilon. However, Angus had greater phosphorylation of phosphoglucomutase-1 and troponin-T (P<0.05). Therefore, proteins involved in contraction and muscle organization, myofilaments expressed in fast or slow-twitch fibers and heat shock proteins localized in mitochondria or sarcoplasmic reticulum and involved in cell flux of calcium and apoptosis might be associated with differences in beef quality between Angus and Nellore. Furthermore, prohibitin appears to be a potential biomarker of intramuscular fat in cattle. Additionally, differences in phosphorylation of myofilaments and glycolytic enzymes could be involved with differences in muscle contraction force, susceptibility to calpain, apoptosis and postmortem glycolysis, which might also be related to differences in beef quality among Angus and Nellore.

In vitro photoautotrophic potential and ex vitro photosynthetic competence of Pfaffia glomerata (Spreng.) Pedersen accessions

This study aimed to investigate whether the in vitro photoautotrophic potential and 20 hydroxyecdysone (20E) production of six Pfaffia glomerata accessions could be correlated to photosynthetic performance and biomass accumulation under ex vitro conditions in a greenhouse environment. Our results showed that P. glomerata accessions displayed varying photosynthetic rates that may have resulted in differential biomass accumulation both in vitro and ex vitro. Accessions A4, A13 and A43 showed the highest dry weight under in vitro photoautotrophic conditions, coinciding with the higher photosynthetic rates of the same accessions in greenhouse. They also showed the highest 20E mass per plant ex vitro. Production of 20E in vitro also varied among accessions, with the highest total mass achieved by accessions A4 and A43. In addition to having the potential for optimizing propagation by reducing the duration of the in vitro culture stage and lessening death rate during acclimatization, the use of these genotypes with higher in vitro photoautotrophic potential can guarantee highly productive plants ex vitro because the biomass accumulation pattern observed in vitro matched that under greenhouse conditions.

Methyl jasmonate and salicylic acid are able to modify cell wall but only salicylic acid alters biomass digestibility in the model grass Brachypodium distachyon

In addition to playing a key role in the response to environmental changes, cell walls are also considered as a valuable feedstock for cellulosic ethanol. Here we explored the effects of the stress-response hormones, salicylic acid and methyl jasmonate, on cell wall biosynthesis and biomass digestibility in Brachypodium distachyon, a species recently considered as a suitable model for biomass conversion. We found that in response to salicylic acid or methyl jasmonate treatment, plant growth was reduced coupled with significant changes in cell wall composition. Cellulose content increased in response to methyl jasmonate whereas a reduction in lignin content was found after salicylic acid application. Moreover, hemicellulose composition was altered and increases in caffeic acid, ferulic acid and p-coumaric acid content were detected in response to both treatments. The hormonal profile and the expression pattern of genes involved in cell wall biosynthesis were also modified. Biomass digestibility was reduced in leaf tissue after salicylic acid treatment and was negatively correlated with ferulic acid and p-coumaric acid content. The results obtained here aid in our understanding of cell wall dynamics in response to stress and will enable the development of new strategies to improve cell wall digestibility in bioenergy feedstock.

Induced polyploidization increases 20-hydroxyecdysone content, in vitro photoautotrophic growth, and ex vitro biomass accumulation in Pfaffia glomerata (Spreng.) Pedersen

The present study aimed to verify the effects of induced polyploidization on Pfaffia glomerata regarding its 20-hydroxyecdysone (20E) production both in vitro and under greenhouse conditions, its in vitro photoautotrophic potential, and its ex vitro biomass accumulation and photosynthetic performance. Synthetic polyploidization efficiently produced individuals with increased in vitro photoautotrophic potential and ex vitro biomass accumulation, although photosynthetic rates per leaf area did not vary between diploids and tetraploids. Among the five tetraploids tested (P28, P60, P68, P74, and P75), P28 showed significantly increased biomass both in vitro and ex vitro when compared with diploid plants, whereas the other tetraploids did not differ significantly from the diploids in terms of biomass accumulation. Although photosynthetic rates per unit leaf area remained constant among all the plants tested, P28 showed a significantly greater total leaf area, which may have resulted in an increase in net photosynthesis on a whole-plant basis. Under greenhouse conditions, the 20E content in the tetraploid P28 was 31% higher than that in diploid plants, and the final 20E mass per plant produced by P28 ex vitro was approximately twice that produced by diploid plants. Accumulation of 20E in vitro did not follow the same pattern observed among the plants ex vitro; instead, greater accumulation was observed in diploid plants. The induction of polyploidy in P. glomerata appears to be a promising strategy for producing plants with higher biomass accumulation and 20E production ex vitro, in addition to its higher in vitro photoautotrophic potential.

Hydroethanolic Extract of Strychnos pseudoquina Accelerates Skin Wound Healing by Modulating the Oxidative Status and Microstructural Reorganization of Scar Tissue in Experimental Type I Diabetes

The effect of topical application of ointment based on Strychnos pseudoquina hydroethanolic extract in the cutaneous wounds healing in diabetic rats was evaluated. Samples of S. pseudoquina were submitted to phytochemical prospection and in vitro antioxidant assay. Thirty Wistar rats were divided into 5 groups: Sal-wounds treated with 0.9% saline solution; VH-wounds treated with 0.6 g of lanolin cream (vehicle); SS-wounds treated with silver sulfadiazine cream (10 mg/g); ES5- and ES10-wounds treated with an ointment of S. pseudoquina extract, 5% and 10%, respectively. Fragments of wounds were removed for histological and biochemical analysis every 7 days during 21 days. ES showed equivalent levels per gram of extract of total phenols and flavonoids equal to 122.04 mg for TAE and 0.60 mg for RE. The chlorogenic acid was one of the major constituents. S. pseudoquina extract presented high antioxidant potential in vitro. ES5 and ES10 showed higher wound healing rate and higher amount of cells, blood vessels, and type III and I collagen. The oxidative stress markers were lower in the ES5 and ES10 groups, while the antioxidants enzymes levels were higher. Ointment based on S. pseudoquina extract promotes a fast and efficient cutaneous repair in diabetic rats.

Differential expression and phytohormone unbalance in Citrus aurantifolia plants during “sudden decline of lime”, a new phytoplasma disease of citrus

For decades, the production of acid lime (Citrus aurantifolia) in Oman has been affected by diseases caused by phytoplasmas, notably witches’ broom disease of lime (WBDL). In recent years, a new phytoplasma strain in Oman has been observed that promotes the sudden decline of lime (SDL). The molecular mechanisms behind its pathogenicity and mode of interaction with citrus host plants is still completely unknown. In this study, we evaluated the differential expression of genes in symptomatic and asymptomatic lime trees in Oman using a real-time quantitative PCR assay. Among 27 regulatory and biosynthesis-related genes tested in Citrus aurantifolia plants during phytoplasma infection, we verified the presence of 14 responsive genes in plants showing SDL symptoms, revealing a specific set of SDL-responsive genes. Quantification data of endogenous 3-indoleacetic acid and jasmonic acid show an unbalanced hormonal content in symptomatic lime trees, corroborating the gene expression data. The identification of regulatory genes differentially expressed in plant-phytoplasma interactions during SDL will help to elucidate the mechanisms possibly involved in defense responses, development and death-triggered signals in infected citrus plants.

Broad range flavonoid profiling by LC/MS of soybean genotypes contrasting for resistance to Anticarsia gemmatalis (Lepidoptera: Noctuidae)

Attack by herbivores is a major biotic stress limiting the soybean crop production. Plant defenses against caterpillars include the production of secondary metabolites such as flavonoids, which constitute a diverse group of plant secondary metabolites. Thus, a more discriminate metabolic profiling between genotypes are important for a more comprehensive and reliable characterization of soybean resistance. Therefore, in this study a non-targeted LC/MS-based for analysis of flavonoid profiles of soybean genotypes contrasting to the resistance to A. gemmatalis was applied. Clustering analysis revealed profiles highly distinct between the susceptible UFV 105 AP and the resistant IAC 17 genotypes. This comparative approach enables to identify directly from leaf extract some new compounds related to resistance, some of which were present in higher abundance specifically in the IAC 17 genotype: four Quercetin conjugates, Rutin (Quercetin 3-O-Rutinoside), Quercetin-3,7-O- di-glucoside, Quercetin-3-O-rhamnosylglycoside-7-O-glucoside and Quercetin-3-O-rhamnopyranosyl-glucopyranoside-rhamnopyranoside; two Genistein conjugates, Genistein-7-O-diglucoside-dimalonylated and Genistein-7-O-6-O-malonylglucoside; and one Daidzein conjugate, Daidzein-7-O-Glucoside-malonate. The most abundant flavonoid glycoconjugates in soybean leaves belongs to Quercetin and Kaempferol classes. However, only one from the identified compounds was classified as a Kaempferol. The Kaempferol-3-O-L-rhamnopyranosyl-glucopyranoside showed high abundance in the resistant genotype IAC 17. The metabolic profiles generated by LC/MS allowed the reconstruction of the flavonoid biosynthetic pathways, which revealed a constitutive character for herbivory resistance in the resistant genotype IAC-17 and a metabolic regulation for the rechanneling of Quercetin, Kaempferol and Genistein conjugates in soybean. Highest relative abundances were detected for glyconjugates, such as Rutin, Quercetin 3-O-rhamnosylglycoside-7-O-glucoside and Quercitin-3-O-rhamnopyranosyl-glucopyranoside-rhamnopyranoside in the leaves of the resistant genotype.