Differences in the cell walls and extracellular polymers of the two Trebouxia microalgae coexisting in the lichen Ramalina farinacea are consistent with their distinct capacity to immobilize extracellular Pb

Autor(es)

Casano, Leonardo M. ^[1] ; Braga, Marcia R. ^[2] ; Alvarez, Raquel ^[1] ; del Campo, Eva M. ^[1] ; Barreno, Eva ^[3]

Afiliação do(s) autor(es)

^[1] Univ Alcala de Henares, Dept Life Sci, Alcala De Henares 28805, Madrid - Spain

^[2] Inst Bot, Dept Plant Physiol & Biochem, BR-04305012 Sao Paulo, SP - Brazil

^[3] Univ Valencia, Dept Bot, ICBIBE, E-46100 Burjassot, Valencia - Spain

• Tipo de documento: Artigo Científico
• Fonte: Plant Science; v. 236, p. 195-204, JUL 2015.
• Citações Web of Science: 8

Resumo

Trebouxia TR1 and T. TR9 are the two microalgae that coexist within Ramalina farinacea thalli. In the presence of Pb, TR9 formed extracellular aggregates, while TR1 showed a lower wall lead retention capability. Herein, we studied the cell walls and extracellular polymers (EPS) of TR1 and TR9, and their possible implication in the different Pb retention capacity of these microalgae. The proportion of cell walls on the overall cell biomass was 2.6 times higher in TR9 than in TR1. Glycosyl linkage analysis indicated the presence of hot-water soluble beta-galactofuranan(s) in both cell walls, distinct from that previously described in Asterochloris, with increased rhamnose content in TR9 and a higher substitution by side chains in TR1. In the EPS of both microalgae, monosaccharide composition resembled their cell walls; however, TR9 produced two times more EPS than TR1. EPS also contained proteins, displaying distinct polypeptide patterns, modulated by Pb in TR9. Uronic acid content in EPS was higher in TR9, and increased in this phycobiont after the addition of Pb. Our findings suggest that the differential extracellular Pb retention capabilities of TR1 and TR9 microalgae can be related to differences in the main features of their cell walls and EPS. (C) 2015 Elsevier Ireland Ltd. All rights reserved. (AU)

• Processo FAPESP: 05/04139-7 - Carboidratos de plantas tropicais como moduladores de processos ecofisiológicos e indicadores de respostas a estresses ambientais
• Beneficiário: Marcia Regina Braga
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 12/16332-0 - Carboidratos de reserva e de parede celular de plantas e de fungos filamentosos: alterações em resposta a aleloquímicos e a variações ambientais
• Beneficiário: Marcia Regina Braga
• Modalidade de apoio: Auxílio à Pesquisa - Regular