Effects of abscisic acid, ethylene and sugars on the mobilization of storage proteins and carbohydrates in seeds of the tropical tree Sesbania virgata (Leguminosae)

Autor(es)

Tonini, Patricia Pinho ^[1] ; Purgatto, Eduardo ^[2] ; Buckeridge, Marcos Silveira ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biosci, Dept Bot, BR-11461 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Food & Expt Nutr, BR-66083 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANNALS OF BOTANY; v. 106, n. 4, p. 607-616, OCT 2010.
• Citações Web of Science: 14

Resumo

Endospermic legumes are abundant in tropical forests and their establishment is closely related to the mobilization of cell-wall storage polysaccharides. Endosperm cells also store large numbers of protein bodies that play an important role as a nitrogen reserve in this seed. In this work, a systems approach was adopted to evaluate some of the changes in carbohydrates and hormones during the development of seedlings of the rain forest tree Sesbania virgata during the period of establishment. Seeds imbibed abscisic acid (ABA), glucose and sucrose in an atmosphere of ethylene, and the effects of these compounds on the protein contents, alpha-galactosidase activity and endogenous production of ABA and ethylene by the seeds were observed. The presence of exogenous ABA retarded the degradation of storage protein in the endosperm and decreased alpha-galactosidase activity in the same tissue during galactomannan degradation, suggesting that ABA represses enzyme action. On the other hand, exogenous ethylene increased alpha-galactosidase activity in both the endosperm and testa during galactomannan degradation, suggesting an inducing effect of this hormone on the hydrolytic enzymes. Furthermore, the detection of endogenous ABA and ethylene production during the period of storage mobilization and the changes observed in the production of these endogenous hormones in the presence of glucose and sucrose, suggested a correlation between the signalling pathway of these hormones and the sugars. These findings suggest that ABA, ethylene and sugars play a role in the control of the hydrolytic enzyme activities in seeds of S. virgata, controlling the process of storage degradation. This is thought to ensure a balanced flow of the carbon and nitrogen for seedling development. (AU)

• Processo FAPESP: 98/05124-8 - Conservação e uso sustentável da biodiversidade vegetal do Cerrado e da Mata Atlântica: o armazenamento de carboidratos e seu papel na adaptação e manutenção de plantas em seu habitat natural
• Beneficiário: Marcos Silveira Buckeridge
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 07/59708-1 - Respostas fisiológicas e bioquímicas de três espécies de leguminosas tropicais às mudanças climáticas
• Beneficiário: Marcos Silveira Buckeridge
• Modalidade de apoio: Auxílio à Pesquisa - Regular