Optimal concentration of selective agents for inhibiting in vitro growth of Urochloa brizantha embryogenic calli

The ability to distinguish transgenic cells of untransformed cell mass is a key step for the production of transgenic plants. Thus, the use of selection marker genes for identification of genetically modified plants is necessary. The aim of this study was to determine the optimal concentration of four selective agents (kanamycin, hygromycin, phosphinothricin and mannose) to inhibit in vitro growth of Urochloa brizantha cv. Marandu calli. Embryogenic calli were obtained from mature seeds inoculated in MS medium supplemented with 30 g/L sucrose, 3 mg/L 2,4 dichlorophenoxy acetic acid (2,4-D) and 300 mg/L hydrolysate casein and their growth rate was monitored for 74 days by measuring calli fresh weight. It was demonstrated that U. brizantha calli are more sensitive to low concentrations of hygromycin than kanamycin (25 and 50 mg/L, respectively). For the herbicide phosphinothricin, 5 mg/L was enough to prevent the calli growth, but allowed escape. Mannose should be used as the only carbon source on the plant tissue culture medium. All selective agents tested here, in the appropriate concentration, could be used in experiments aiming to produce transgenic signal grass. However, mannose selection might reduce environmental concerns about gene flow and development of herbicide resistance in escaped Urochloa populations.Keywords: Signal grass, transformation, marker genes, selectio

A GENOME-WIDE ANALYSIS OF THE GALACTINOL SYNTHASE GENE FAMILY IN BANANA (Musa acuminata)

Galactinol synthase (GolS) is the enzyme that catalyzes the first step of the biosynthesis of the raffinose family oligosaccharides (RFOs), and are involved in many biological processes in plants. In the present study, four putative GolS genes were identified in the Musa acuminata genome. We further characterized these MaGolS genes in terms of protein length, molecular weight, theoretical isoelectric point and 3D proteins structure. Genomic organization revealed that most MaGolS genes have four exons. The conserved motifs were identified, demonstrating high group-specificity of all MaGolS proteins. Multiple sequence alignment showed that the APSAA typical domain is present in all GolS proteins. Comparative phylogenetic analysis of the MaGolS proteins revealed three distinct groups. These data provides insight to support new studies adressing the role of GolS genes in this important fruit species.A galactinol sintase (GolS) é a enzima que catalisa o primeiro passo da biossíntese dos oligossacarídeos da família da rafinose (OFRs) e está envolvida em muitos processos biológicos nas plantas. No presente estudo, quatro genes GolS foram identificados no genoma de Musa acuminata. Esses genes MaGolS foram caracterizados em termos de comprimento de proteína, peso molecular, ponto isoelétrico teórico e estrutura de proteínas 3D. A organização genômica revelou que a maioria dos genes MaGolS possui quatro éxons. Os motivos conservados foram identificados, demonstrando alta especificidade de grupo de todas as proteínas MaGolS. O alinhamento múltiplas de sequências mostrou que o domínio típico de APSAA está presente em todas as proteínas GolS. A análise filogenética comparativa das proteínas MaGolS revelou três grupos distintos. Estes dados fornecem insights para apoiar novos estudos sobre o papel dos genes GolS nesta importante espécie frutífera

IN SILICO ANALYSIS OF THE Dof TRANSCRIPTION FACTOR FAMILY IN Coffea canephora

The Dof family (DNA-binding with One Finger) is a group of transcription factors that are involved in a variety of functions of importance for different biological processes in plants, such as plant growth, development and response to biotic and abiotic stresses. The Dof genes have been identified and characterized in many plant species, but so far there is no information about these genes in coffee species. In the present study, we identified 24 Dof members in Coffea canephora using the Coffee Genome Hub database. Systematic bioinformatics analyses were performed to characterize all CcDof genes, including complete genome sequence, conserved protein domains, subcellular locations, phylogenetic relationships and gene expression profiles in different tissues. The results obtained here provide new insights into the CcDof gene family, allowing the design of future experiments for the molecular characterization of these genes in coffee plants.A família Dof (DNA-binding with One Finger) é um grupo de fatores de transcrição que desempenham papéis importantes no crescimento, desenvolvimento e na resposta das plantas aos estresses bióticos e abióticos. Os genes Dof foram identificados e caracterizados em várias espécies de plantas; entretanto até o presente momento não há informações sobre esses genes em café. No presente estudo foram identificados 24 membros da família Dof no genoma de C. canephora depositados no banco de dados Coffee Genome Hub. Análises sistemáticas de bioinformática foram realizadas para caracterizar os genes Dof em C. canephora, incluindo a análise de sequências genômicas, domínios proteicos conservados, localizações subcelulares, relações filogenéticas e perfis de expressão gênica em diferentes tecidos. Os resultados obtidos fornecem uma melhor compreensão sobre a família dos genes Dof permitindo projetar experimentos futuros para caracterização molecular desses genes no cafeeiro