Search

Sweet potato exhibits a prostrate growth habit, which makes weed management to be manually performed or conducted through the application of selective herbicides. Considering the absence of registered herbicides for the selective control of broad leaf weeds on the sweet potato crop, we investigated the physiological and agronomic responses of the sweet potato cultivar Duda, selected for its great potential in biofuel production, to different post-emergence herbicides. Two experiments, one conducted under field conditions and the other under controlled (potted plants) conditions, were performed under a randomized complete block design, with four replicates each. Four different herbicides, atrazine and S-metolachlor (3,5 L.ha-1), carfentrazone-ethyl (0,75 L.ha-1), fomesafen and fluazifop-P-butyl (1,8 L.ha-1) and nicosulfuron (1,25 L.ha-1), were used and the experiments were composed by five treatments with the control (no herbicide application) treatment,. Physiological indicators, including carbon assimilation, stomatal conductance, leaf transpiration rate, internal CO2 concentration, and water-use efficiency were monitored at 24 h, 48 h and 15 d after herbicides application, while agronomic evaluations were performed at 30 and 152 days from herbicide application. Application of atrazine (inhibitor of photosystem II) together with S-metolachlor (inhibitor of cell division/elongation) led to reductions on the physiological indices soon after treatment imposition but it had no effect on dry matter accumulation in the shoot, nor on the roots, not affecting the starch content, storage root productivity, and estimated ethanol production as well. In contrast, application of carfentrazone-ethyl, a protoporphyrinogen oxidase inhibitor, exerted significant negative physiological and agronomic effects, decreasing root productivity and estimated ethanol yield. We conclude that the use of atrazine in a mixture with S-metolachlor represents a suitable selective approach for the control of broad leaf weeds in sweet potato crops.

High temperatures can negatively affect lettuce production by promoting early bolting, which leads to increased levels of latex accumulation in the leaves, causing them to become bitter. The lack of adaptation of this culture to such conditions made it an object of study for plant breeding programs, resulting in well succeeded studies. However, little is known about the genes that regulate lettuce flowering. A better understanding of the complex genic interactions involved in the process of lettuce floral initiation is of great importance, since it can enable the development of late-bolting cultivars through plant genetic transformation. MADS-box transcriptional factors are key flowering regulators and have been extensively studied during the flowering process in several species. Thus, this study aimed to identify and characterize the Lettuce MADS-box gene family through the use of bioinformatics tools. The computational analysis consisted in gene prediction, alignment, and phylogenetic analysis. 91 sequences of putative MADS-box genes were identified and characterized by a phylogenetic study of 20 MADS-box genes. Future studies comprising mutants for these genes in plant model species and in lettuce will enable a better understanding of the functions performed by these genes during lettuce flowering, as well as, a better comprehension of this process.

With ample cultivation and economic potential, coffee is one of the main commodities in the world. Despite its vast cultivation, there remain problems related to its productivity as a consequence of pests and diseases, questions regarding its physiology, and difficulty with its propagation. Due to such challenges, the application of biotechnological tools, such as tissue culture and molecular markers, has become essential in the search for improvements to coffee cultivation. Among tissue culture techniques, somatic embryogenesis is considered the best form of micropropagation in vitro since it is possible to produce plants that are identical to the parent plant. It is therefore essential to identify the genes involved in the process of somatic embryogenesis, as well as to understand their functions. Different studies have shown the expression of ethylene response factor (ERF) genes in different tissues and under different conditions, mainly in response to biotic and abiotic stresses. However, little is known about their role during somatic embryogenesis. Thus, this study is aimed to identify and analyze the expression patterns of ERF subfamily genes during Coffea arabica L. somatic embryogenesis. The EST-contig6, 9, and 27 were confirmed to be the ethylene response factor 8, 13, and 12 genes from Coffea arabica L., respectively, and their relative expression analysis suggests that they may be involved in coffee somatic embryogenesis. The expression patterns of ethylene response factor 8 and 13 in embryogenic calluses and embryogenic cell suspensions showed that these genes can potentially act as somatic embryogenic markers.

Growing coffee faces challenges regarding the development and productivity of plants. To improve coffee tree cultivation and bean productivity and quality, modern techniques of plant biotechnology need to be adopted that allow the development of more productive and resistant varieties. Among these, somatic embryogenesis stands out as a method of great potential for the propagation of coffee plants in vitro. Some genes are directly related to somatic embryogenesis, especially WOX (WUSHEL-related HOMEOBOX) genes, which play a central role in the process. Therefore, the objective of this study was to identify and analyze the expression pattern of WOX genes in arabica coffee, Coffea arabica. In silico analyses identified seven WOX genes in arabica coffee: Coffea arabica WUSHEL-like (CaWUS-like), Coffea arabica WOX1-like (CaWOX1-like), CaWOX3-like, CaWOX4-like, CaWOX5-like, CaWOX9-like and CaWOX11-like. The transcriptional profile of the CaWOX11-like gene suggests that it may be intrinsically related to the embryogenic process and may be used as a molecular marker. In addition, comparisons of the present results with those from the literature indicate that WOX genes are key regulators of somatic embryogenesis in arabica coffee.

In many legume species, somatic embryogenesis is a limiting step of in vitro regeneration, with profound implications to genetic engineering and plant breeding. In Arabidopsis thaliana, the small AFL subfamily of B3-type transcriptional factors is composed by LEC2 (LEAFY COTYLEDON 2), FUSCA (FUSCA3), and ABI3 (ABSCISIC ACID INSENSITIVE 3), which are directly involved in both zygotic and somatic embryogenesis. This study aimed to identify and analyze the expression profile of AFL subfamily genes during in vitro induction of the somatic embryogenesis in the model legume Medicago using near-isogenic genotypes contrasting for their capability of regenerating in vitro. Three AFL genes were identified in the Medicago truncatula genome: MtLEC2, MtFUSCA3 and MtABI3. RT-qPCR was used to compare the expression of these genes during the induction of somatic embryogenesis in the embryogenic genotype M9-10a and the non-embryogenic genotype M9. The AFL genes identified were highly expressed 10 days after introducing leaflet explants in vitro in the embryogenic genotype (M9-10a), whereas absence or low expression was observed in explants of the non-embryogenic genotype (M9). During zygotic embryogenesis, the Medicago Gene Atlas revealed that expression of MtFUSCA3 and MtABI3 occurred specifically during seed development, starting at 10 days after pollination. This study allowed for the identification and transcriptional characterization of MtLEC2, MtFUSCA3, and MtABI3. The expression pattern of these genes in the M9-10a genotype suggests they are involved in the Medicago truncatula somatic embryogenesis. The transcriptional profile of AFL transcription factors highlights the evolutionary conservation of this developmental pathway between the Arabidopsis and Medicago lineages and opens avenues to improve the efficiency of in vitro embryogenesis in legume crops. Expression of MtLEC2, MtFUSCA3, and MtABI3 genes was induced during somatic embryogenesis and these genes to be used as in vitro regeneration biomarkers as well as to improving somatic embryogenic rates in legumes and other crops recalcitrant to in vitro regeneration.

The employment of biotechnology-based approaches such as somatic embryogenesis has been applied to several plants including Coffea sp. Despite the economic importance of this genus, few information about the role of key regulatory genes in somatic embryogenesis in coffee is available. This work provides information about ABI3 and VAL2 genes performance by RT-qPCR during indirect somatic embryogenesis of Coffea arabica. To achieve this, bioinformatics analysis was performed to identify the genes of the B3 superfamily in the coffee genome. The cell suspensions lines presented similar histological and regeneration patterns, yielding of up to 6.6 embryos per 1 mg of embryogenic aggregates at 7 months. We have identified possible orthologs for VAL2 (Cc06g00410) and ABI3 (Cc01g17380) as well as the other members belonging to superfamily B3. The CaABI3 expression was higher in dedifferentiated competent cells for somatic embryogenesis as compared with non-embryogenic calli. Whereas the expression of VAL2 gene is more active in cotyledonary embryos and plantlets, showing its clear performance in the embryogenesis late stages. The present study suggests that CaABI3 gene could be potentially used as a biomarker for embryogenic process improvement. The good plantlets development obtained from the protocol used may be a reflection of the high expression of CaVAL2 in cotyledonary embryos and plantlets. The activity of CaABI3 is correlated to embryogenic potential with highly expressed in embryogenic masses and expression of the VAL2 gene is increased at the end of the embryogenic process.

Isolating high quality RNA is a limiting factor in molecular analysis, since it is the base for transcriptional studies. The RNA extraction method can directly affect the RNA quality and quantity, as well as, its overall cost. The industrial importance of the yeast genus Candida in several sectors comes from their capacity to produce Lipases. These enzymes are one of the main metabolites produced by some Candida species, and it has been shown that Candida yeast can biodegrade petroleum hydrocarbons and diesel oil from biosurfactants that they can produce, a feature that turns these organisms into potential combatants for bioremediation techniques. Thus, this study aimed to determine an efficient method for isolating high quality RNA from Candida viswanathii biomass. To achieve this aim, three different RNA extraction methods, TRIzol, Hot Acid Phenol, and CTAB (Cetyltrimethylammonium Bromide), were tested. The three tested methods allowed the isolation of high-quality RNA from C. viswanathii biomass and yielded suitable RNA quantity for carrying out RT-qPCR studies. In addition, all methods displayed high sensitivity for the expression analysis of the CvGPH1 gene through RT-qPCR, with TRIzol and CTAB showing the best results and the CTAB method displaying the best cost-benefit ratio (US$0.35/sample).

Made available in DSpace on 2022-04-28T19:28:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Different fat ingredients and their fatty acids may influence the expression of genes responsible to encode enzymes and proteins linked to adipose tissue deposition, influencing beef quality. Therefore, the objective was to analyze the expression of PPARA, SREBF1 and genes involved in lipid metabolism in longissimus thoracis (LT) muscle of cattle fed diets containing soybean or cottonseed with or without vitamin E. Twenty-eight bulls were used in a completely randomized design using a 2 × 2 factorial arrangement. The inclusion of soybean and cottonseed in the diets provided 64.8 g kg−1 and 65.6 g kg−1 of ether extract, respectively, and vitamin E supplementation was 2500 IU per day. The PPARA expression was greater and SREBF1 expression was lower in the muscle of animals fed soybean (P

Coffee is one of the most economically important commodities. In Brazil, this crop is responsible for generating more than eight million jobs. In the foreign market, Brazil is the largest producer and exporter of coffee. Due to its economic importance, several studies aiming the improvement of coffee are conducted, but there are still problems related to its productivity and quality of the beverage, such as sequential flowering, which causes production losses and a low quality drink. Thus, understanding the molecular mechanisms involved in the flowering process is essential to elucidate how flowering occurs in the coffee crop. The FRI gene is one of the main genes involved in flowering, as it positively regulates the FLC gene at expression levels that inhibit flowering. Thus, the objective of this work was to identify and analyze the expression of the FRIGIDA4-like gene (FRL4) through Bioinformatics and real-time PCR (RT-qPCR). The CaFRL4 gene was identified and showed high expression levels in leaf during flowering, which corroborates with the literature. The results obtained provide the basis for future studies involving genetic transformation in model plants and coffee, permitting the functional characterization of this gene.

Fruit ripening can be seen as an oxidative phenomenon that, depending on its intensity, may directly influence fruit quality. At relatively higher altitudes, coffee fruit ripening takes place through an extended period of time, which positively affects coffee quality. However, little is known about the oxidative processes and antioxidant metabolism of coffee fruits grown at these altitudes. Thus, this study aimed to characterise coffee fruit development from trees grown at two contrasting altitudes (965 m and 1310 m) through phenological analysis and antioxidant metabolism evaluation (Hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents; superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activity and gene expression). Phenological analysis showed that altitude extended coffee reproductive cycle by a month and promoted a higher ripening uniformity, with 100% of fruits at the ideal ripening stage for harvest (cherry stage) in the last evaluation time. H2O2 and malondialdehyde contents revealed that in both altitudes fruits went through oxidative damage, though in an early manner at the lower altitude. Although gene expression and enzyme activity did not well correlate, the delay in the oxidative damage in fruits of the higher altitude was probably a result of an increased efficiency in H2O2 neutralisation due to the higher activity levels of the APX and CAT enzymes, mainly in green fruits. Thus, a better removal of reactive oxygen species in coffee fruits from plants grown at higher altitudes is involved in the extension of the coffee reproductive cycle, contributing to the production of a higher cup quality coffee.

Natural flowering can cause serious scheduling problems in the pineapple (Ananas comosus) industry and increase harvest costs. Pineapple flowering is thought to be triggered by increased ethylene levels and artificial forcing of pineapple flowering is a common practice to promote flowering synchronisation. However, little is known about the early hormonal and molecular changes of pineapple flowering induction and development. Here, we aimed to analyse the molecular, hormonal, and histological changes during artificial pineapple flowering by Ethrel®48 treatment. Histological analyses of the shoot apical meristem, leaf gibberellic acid (GA3), and ethylene quantification were carried out during the first 72h after Ethrel®48 treatment. Expression profiles from ethylene biosynthesis (AcACS2 and AcACO1), gibberellin metabolism (AcGA2-ox1 and AcDELLA1), and flower development (FT-like gene (AcFT), LFY-like gene (AcLFY), and a PISTILLATA-like gene (AcPI)) genes were analysed during the first 24h after Ethrel®48 treatment. Differentiation processes of the shoot apical meristem into flower buds were already present in the first 72h after Ethrel®48 treatment. Ethrel®48 lead to a reduction in GA3 levels, probably triggered by elevated ethylene levels and the positive regulation AcGA2-ox1. AcLFY activation upon Ethrel®48 may also have contributed to the reduction of GA3 levels and, along with the up-regulation of AcPI, are probably associated with the flower induction activation. AcFT and AcDELLA1 do not seem to be regulated by GA3 and ethylene. Decreased GA3 and increased ethylene levels suggest an accumulation of AcDELLA1, which may display an important role in pineapple flowering induction. Thus, this study shows that molecular, hormonal, and histological changes are present right after Ethrel®48 treatment, providing new insights into how pineapple flowering occurs under natural conditions.

Quantitative real-time PCR (qPCR) is a sensitive method used to investigate relevant changes in gene expression during somatic embryogenesis. Understanding its regulatory network might be helpful to the process of induction of embryos and facilitate the development of efficient plant regeneration procedures. In this study, a set of 12 genes was selected and their stability was assessed in different tissues of somatic embryogenesis-related cultures of Coffea arabica. Analyses of gene expression stability were performed using the RefFinder tool that integrates the geNorm, NormFinder, BestKeeper and Delta-Ct algorithms. Among the all candidate reference genes studied, APRT/EF1a, UBQ/ACT, ACT/24S, RPL39/24S, PP2A/RPL39, PP2A/AP47, emerged as the most stable for normalization of qPCR analyses of embryogenic cell suspensions, non-embryogenic calli, embryogenic calli, combined embryogenic and non-embryogenic calli, somatic embryos and plantlet, respectively. A combination of two genes, 24S and PP2A, was identified as most suitable reference genes across all samples for the C. arabica tissues studied. The commonly employed reference gene encoding glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was found to be inappropriate as a reference gene for embryogenic tissues of C. arabica. In addition, Baby boom (BBM) gene expression was investigated to confirm the validity of the selected reference genes, the transcript levels of gene were overestimated when unsuitable reference genes were used for normalization. The results shown herein will permit a more precise and reliable normalization of qPCR in experiments involving somatic embryogenesis of C. arabica.

The reliability of analyses using real-time quantitative polymerase chain reaction (RT-qPCR) depends on the selection of appropriate reference genes to correct for sample-to-sample and run-to-run variations. The aim of the present study was to select the most suitable reference genes for gene expression analyses in tissue samples from coffee, Coffea arabica L. (Arabica) grown under well-watered (WW) and water-deficit (WD) conditions and C. canephora Pierre ex A. Froehner (Robusta) grown under WW conditions. Expression profiles and stabilities were evaluated for 12 reference genes in different tissues from C. arabica and for 8 genes in tissues from C. canephora. The web-based RefFinder tool, which combines the geNorm, NormFinder, Bestkeeper, and Delta-Ct algorithms, was employed to assess the stability of the tested genes. The most stable reference genes identified for all tissues grouped (WW/WD) of C. arabica were clathrin adaptor protein medium subunit (AP47), ubiquitin (UBQ), 60S ribosomal protein L39 (RPL39), and elongation factor 1α (EF1α), while class III alcohol dehydrogenase (ADH2), β-actin (ACT), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and ubiquitin (UBQ) genes were the most stable for all tissues grouped (WW) of C. canephora tissues. Validation by the expression level analysis of CaACO-like demonstrated that the use of the best and the worst set of reference genes produced different expression results. The results reinforce the general assumption that there is no universal reference gene and that it is essential to select the most appropriate gene for each individual experiment to apply adequate normalization procedures of RT-qPCR data.

Degree of unsaturation of fatty acids, which is influenced by lipid source and level of metabolism in the rumen, is a major determinant in how dietary lipids affect genes that regulate beef marbling. A total of 28 Red Norte bulls with an initial live weight of 361±32 kg (P>0.05) were used in a completely randomized experimental design to analyze the expression of genes that are involved in lipid metabolism in the longissimus dorsi (LD) when diets contained soybean grain or rumen-protected fat, with or without monensin. Treatments were arranged as a 2×2 factorial, with 4 treatments and 7 replicates per treatment. Half of the animals that received soybean or rumen-protected fat were supplemented with 230 mg head(-1) d(-1) of monensin. Gene expression was analyzed by reverse-transcription quantitative PCR (RT-qPCR). Expression of sterol regulatory element-binding protein-1c (SREBP-1c) in the LD muscle was not affected by lipid source or monensin (P>0.05). There was an interaction effect (P

Coffee quality is strongly influenced by a great number of factors, among which the fruit ripening stage at harvest time has a major influence on this feature. Studies comprising ethylene production and the regulation of ethyl- ene biosynthesis genes during the ripening process indicate that ethylene plays an important role on coffee fruit ripening. Coffee early cultivars usually show a more uniform ripening process although little is known about the genetic factors that promote the earliness of ripening. Thus, in order to better understand the physiological and genetic factors involved in the regulation of ripening time, and consequently ripening uniformity, this study aimed to analyze ethylene and respi- ration patterns during coffee ripening, as well as to analyze ACC oxidase, an ethylene biosynthesis enzyme, gene expression, in fruits of early (Catucao ´ 785-15) and late (Acaua ˜) coffee cultivars. Coffee fruits were harvested monthly from 124 days after flowering (end of February), until complete maturation (end of June). Dry matter, mois- ture content, color, respiratory rate and ethylene production analysis were performed. In silico analysis identified a coffee ACC oxidase gene (CaACO-like )a nd its expression was analyzed by real-time PCR. Dry matter and relative water content constantly increased and gradually decreased, respectively, during fruit ripening, and the color analysis enabled the observation of the earliness in the ripening pro- cess displayed by Catucao ´ 785-15 and its higher fruit ripening uniformity. The results obtained from the CaACO-like expression analysis and respiration and ethylene analysis suggest that the differences in ripening behavior between the two coffee cultivars analyzed in this study may be related to the differences in their capacity to produce ethylene, with fruits of Catucao ´ 785-15 and Acauashowing a typical and an attenuated climacteric phase, respectively, which may have lead to differences in their ripening time and uniformity.

The sequential pattern of coffee flowering is a major constraint that directly affects productivity, increases harvest costs, and generates a final product of lower quality for mixing dry fruits with ripe and unripe ones. The objective of this work was to identify and analyze one of the main genes involved in flowering regulation, FLOWERING LOCUS C (FLC) in coffee (Coffea arabica L.). The identification of this gene was conducted in silico using a coffee EST database (CAFEST) and bioinformatics tools. Quantitative PCR results suggest that the identified CaFLC-like homologue is directly involved in flowering regulation in coffee. This expands our knowledge on evolutionary conservation of flowering pathways in dicot species. The functional studies of CaFLC-like with mutants of a more tractable species will lead to a better understanding of the molecular regulation as well as the specific functions of each gene flowering during floral induction in coffee.

The plant hormone ethylene is involved in the regulation of a multitude of plant processes, ranging from seed germination to organ senescence. Ethylene induces fruit ripening in climacteric fruits, such as coffee, being directly involved in fruit ripening time and synchronization. Coffee early cultivars usually show a more uniform ripening process although little is known about the genetic factors that promote the earliness of ripening. Thus, this work aimed to characterize the putative members of the coffee (Coffea arabica) ethylene biosynthesis and signaling pathways, as well as to analyze the expression patterns of these members during fruit ripening of early (Catucai 785-15) and late (Acaua) coffee cultivars. Reverse Transcription-qPCR analysis of the four biosynthesis genes (CaACS1-like; CaACO1-like; CaACO4-like e CaACO5-like) analyzed in this study showed that CaACO1-like and CaACO4-like displayed an expression pattern typically observed in climacteric fruits, being up-regulated during ripening. CaACS1-like gene expression was also up-regulated during fruit ripening of both cultivars, although in a much lesser extent when compared to the changes in CaACO1-like and CaACO4-like gene expression. CaACO5-like was only induced in raisin fruit and may be related to senescence processes. On the other hand, members of the ethylene signaling pathway (CaETR1-like, CaETR4-like, CaCTR2-like, CaEIN2-like, CaEIN3-like, CaERF1) showed slightly higher expression levels during the initial stages of development (green and yellow-green fruits), except for the ethylene receptors CaETR1-like and CaETR4-like, which were constitutively expressed and induced in cherry fruits, respectively. The higher ethylene production levels in Catucai 785-15 fruits, indicated by the expression analysis of CaACO1-like and CaACO4-like, suggest that it promotes an enhanced CaETR4-like degradation, leading to an increase in ethylene sensitivity and consequently to an earliness in the ripening process of this cultivar. Ethylene production in Acaua fruits may not be sufficient to inactivate the CaETR4-like levels and thus ripening changes occur in a slower pace. Thus, the expression analysis of the ethylene biosynthesis and signaling genes suggests that ethylene is directly involved in the determination of the ripening time of coffee fruits, and CaACO1-like, CaACO4-like and CaETR4-like may display essential roles during coffee fruit ripening.

Made available in DSpace on 2019-06-19T01:15:26Z (GMT). No. of bitstreams: 1 Silicoandinvivo.pdf: 2006646 bytes, checksum: fdb4ea1794f6c0ea9912ad66c8647e24 (MD5) Previous issue date: 2019