Functional analysis of MiRNAs involved in the development of legume seeds

• Autor(a) principal: Prata, Diogo Manuel Carvalho
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/120627
• topic: Seed development; Medicago truncatula; miRNA; MIM; transformation; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química

To feed an ever-increasing population worldwide, new strategies for improving agriculture must be found. In the continents of South America, Asia and Africa, there is a prevalent usage of legumes, such as the common beans (Phaseolus vulgaris) and soy (Glycine max). To boost the yield of these crops, we need to better understand the development of seeds and in this study the focus is on the effect of the expression of micro RNAs (miRNAs), specifically miR408, during the development of the seeds in the model legume Medicago truncatula (M. truncatula), as well as creating new transformed plants. In P. vulgaris several miRNAs have already been identified to influence the development of the seed, such as miR399a and miR166a and in M. truncatula, there are reports of miR408 influencing the number of seeds per pod. As a starting point, a bioinformatic analysis was conducted to search for miR399a and miR166a equivalents in M. truncatula and their predicted targets as well as the predicted targets of M. truncatula miR408. For all the three miRNAs, the predictions aligned with the bibliography. Using a transformed plant (Mtr-MIM408) that had a mimic of miR408 (MIM408), a transcript complementary to the miRNA that downregulates it, the expression level of miR408 were measured. Because the control samples showed expression of MIM408, no comparison between expression of miR408 and its target between plants could be made. Regarding the transformation of plants, the fragments containing the mimic for miR166a and miR399a were successfully synthetized but failed to be inserted in a binary vector used for transformation M. truncatula. Finally, the transformed plants showed delayed blooming and had fewer seeds per pod, similar to what is found in literature. In short, this work will be a steppingstone in the process of understanding the impact of the expression of these miRNAs in seed development.