Project description:In plants and parenchymatous brown algae the body arises through the activity of an apical meristem (a niche of cells or a single cell). The meristem produces lateral organs in specific patterns, referred to as phyllotaxis. In plants, two different control mechanisms have been proposed: one is position-dependent and relies on morphogen accumulation at future organ sites; the other is a lineage-based system which links phyllotaxis to the apical cell division pattern. Here we examine the apical patterning of the brown alga, Sargassum muticum, which exhibits spiral phyllotaxis (137.5° angle) and an unlinked apical cell division pattern. The Sargassum apex presents characteristics of a self-organising system, similar to plant meristems. In contrast to complex plant meristems, we were unable to correlate the plant morphogen auxin with bud positioning in Sargassum, nor could we predict cell wall softening at new bud sites. Our data suggests that in Sargassum muticum there is no connection between phyllotaxis and the apical cell division pattern indicating a position-dependent patterning mechanism may be in place. The underlying mechanisms behind the phyllotactic patterning appear to be distinct from those seen in plants.
Project description:The replacement of synthetic compounds by natural products witnesses an increasing demand from the pharmaceutical, cosmetic, food and nutraceutical industries. Included in the set of natural raw materials that are poorly explored are the macroalgae. Despite the detailed characterization and identification of most relevant biomolecules that are present in the main macroalgae species, there remains a lack of efficient and economically viable processes available to meet the needs of the markets. In this work, an efficient and single-step process, based on aqueous solutions of Tween 20, to recover carotenoids from Sargassum muticum, an invasive brown macroalgae species present in the Portuguese coast, is proposed and optimized allowing an extraction yield of 2.78 ± 0.4 mgcarotenoids.gdried mass-1, which is shown to increase the extraction efficiency by 38% when compared with traditional methods.
Project description:Wheat (Triticum aestivum L.) rusts are a worldwide production problem. Plant breeders have used genetic resistance to combat these fungi. However, single-gene resistance is rapidly overcome as a result of frequent occurrence of new virulent fungal strains. Thus, a supply of new resistance sources is continually needed, and new resistance sources are limited within hexaploid wheat genetic stocks. Wild relatives are able to be a resource for new resistance genes but are hindered because of chromosome incapability with domesticated wheats. Twenty-eight double-haploid hexaploid wheat/Amblyopyrum muticum (Boiss.) Eig introgression lines, with introgressions covering the majority of the T genome, were evaluated for resistance to Puccinia triticina Erikss., P. graminis Pers.:Pers. f.sp. tritici Erikss. & E. Henning, and P. striiformis Westend. f.sp. tritici Erikss.. At the seedling level, four lines were resistant to races of P. triticina, six lines were resistant to P. graminis, and 15 lines were resistant to P. striiformis. At the adult stage, 16 lines were resistant to P. triticina. Line 355 had resistance to all three rusts and line 161 had resistance to all tested races of P. triticina. Some of these lines will require further work to reduce the size of the introgressed segment; however, lines 92 and 355 have very small fragments and can be used directly as new resistance donors.