Browsing by Author "Sperotto, Raul A."
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- Biostimulant effect of two fucus sp. algal residues on pea, rice, and tomato germination and growthPublication . Sperotto, Raul A.; Rosa-Martínez, Elena; Martins, Valter F. R.; Pintado, Manuela; Morais, Rui M. S. C.; Morais, Alcina M. M. B.; Vasconcelos, Marta W.Introduction: Seaweed-based bioproducts are increasingly recognized for their phytostimulatory properties, promoting plant growth and enhancing resistance to various stresses. Notably, Fucus vesiculosus, a brown seaweed, has shown promise as a biostimulant1. Exopolysaccharides (EPSs) constitute different classes of organic macromolecules that can have multiple applications. This study investigates the bioestimulant effects of Fucus sp. on the germination and early growth of pea, rice, and tomato, utilizing two algal extracts—one with EPS and another without EPS. The goal was to assess the impact of the algal residues on seed germination and initial plant development and provide insights into their potential as sustainable biostimulants. Conclusions: The three crops responded differently to applying algae extracts in the substrate as a biostimulant. The most promising results were obtained for rice and tomato since they showed a biostimulating effect on crop growth in the early stages of development, which was demonstrated mainly in the significant increase in plant dry biomass. Ultimately, the algae residue without EPS (BS-EPS at both concentrations) gave better results than the algae residue with EPS, as it significantly promoted the development of rice and tomato seedlings.
- From soil to seed: micronutrient movement into and within the plantPublication . Sperotto, Raul A.; Ricachenevsky, Felipe K.; Williams, Lorraine E.; Vasconcelos, Marta; Menguer, Paloma K.
- Integrated valorization of fucus spiralis alga: polysaccharides and bioactives for edible films and residues as biostimulantsPublication . Martins, Valter F. R.; Coelho, Marta; Machado, Manuela; Costa, Eduardo; Gomes, Ana M.; Poças, Fátima; Sperotto, Raul A.; Rosa-Martínez, Elena; Vasconcelos, Marta; Pintado, Manuela E.; Morais, Rui M. S. C.; Morais, Alcina M. M. B.Fucus spp. seaweeds thrive in the cold temperate waters of the northern hemisphere, specifically in the littoral and sublittoral regions along rocky shorelines. Moreover, they are known to be a rich source of bioactive compounds. This study explored the valorization of Fucus spiralis through the extraction of bioactives and polysaccharides (PSs) for food applications and biostimulant use. The bioactives were extracted using microwave hydrodiffusion and gravity (MHG), where the condition of 300 W for 20 min resulted in the highest total phenolic content and antioxidant activity of the extract. Cellular assays confirmed that the extract, at 0.5 mg/mL, was non-cytotoxic to HaCat cells. Polysaccharides (PSs) were extracted from the remaining biomass. The residue from this second extraction contained 1.5% protein and 13.35% carbohydrates. Additionally, the free amino acids and minerals profiles of both solid residues were determined. An edible film was formulated using alginate (2%), PS-rich Fucus spiralis extract (0.5%), and F. spiralis bioactive-rich extract (0.25%). The film demonstrated significant antioxidant properties, with ABTS and DPPH values of 221.460 ± 10.389 and 186.889 ± 36.062 µM TE/mg film, respectively. It also exhibited notable physical characteristics, including high water vapor permeability (11.15 ± 1.55 g.mm.m−2.day−1.kPa−1) and 100% water solubility. The residues from both extractions of Fucus spiralis exhibited biostimulant (BS) effects on seed germination and seedling growth. BSs with PSs enhanced pea germination by 48%, while BSs without PSs increased the root dry weight of rice and tomato by 53% and up to 176%, respectively, as well as the shoot dry weight by up to 38% and up to 74%, respectively. These findings underscore the potential of Fucus spiralis within the framework of a circular economy, wherein both extracted bioactives and post-extraction by-products can be used for sustainable agriculture and food applications.
- Whole-plant mineral partitioning during the reproductive development of rice (Oryza sativa L.)Publication . Sperotto, Raul A.; Vasconcelos, Marta W.; Grusak, Michael A.; Fett, Janette P.Minimal information exists on whole-plant dynamics of mineral flow. Understanding these phenomena in a model plant such as rice could help in the development of nutritionally enhanced cultivars. A whole-plant mineral accumulation study was performed in rice (cv. Kitaake), using sequential harvests during reproductive development panicle exertion, grain filling, and full maturity stages in order to characterize mineral accumulation in roots, non-flag leaves, flag leaves, stems/sheaths, and panicles. Partition quotient analysis showed that Fe, Zn, Cu and Ni are preferentially accumulated in roots; Mn and Mg are accumulated in leaves; Mo, Ca, and S in roots and leaves; and K in roots, leaves and stems/sheaths. Correlation analysis indicated that changes in the concentrations of mineral pairs Fe-Mn, K-S, Fe-Ni, Cu-Mg, Mn-Ni, S-Mo, Mn-Ca, and Mn-Mg throughout the reproductive development of rice were positively correlated in all four of the above ground organs evaluated, with Fe-Mn and K-S being positively correlated also in roots, which suggest that root-to-shoot transfer is not driven simply by concentrations in roots. These analyses will serve as a starting point for a more detailed examination of mineral transport and accumulation in rice plants