| Full text | |
| Author(s): |
Total Authors: 4
|
| Affiliation: | [1] Universidade Estadual de Campinas. Departamento de Biologia Celular - Brasil
[2] Instituto de Botânica. Seção de Fisiologia e Bioquímica de Plantas - Brasil
[3] University of Georgia. Complex Carbohydrate Research Center - Estados Unidos
[4] Instituto de Botânica. Seção de Fisiologia e Bioquímica de Plantas - Brasil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | Rev. bras. Bot.; v. 28, n. 4, p. 735-744, 2005-12-00. |
| Abstract | |
Plants accumulate antimicrobial compounds (phytoalexins) in response to a wide variety of microorganisms. Mucor ramosissimus Samutsevitsch is a saprobe capable of inducing phytoalexin production in soybean cotyledons and in the leaves of tropical Rubiaceae on whose surface it has been found. In the present study, the elicitor from M. ramosissimus was partially purified and the activity compared to that of a glucan elicitor isolated from Phytophthora sojae. Optimal isolation of the elicitor (based on fungal growth, yield of spores and elicitor activity) was achieved by autoclaving spores obtained from nine day-old cultures of the fungus. The elicitor was precipitated with ethanol and purified by chromatography on an anion exchange column, which retained the elicitor, and a Concanavalin A-affinity matrix, to which the elicitor did not bind. The purification resulted in a considerable increase (six-fold) in the specific activity of the elicitor. Neutral sugar composition, analyzed by HPLC, revealed the predominance of mannose, followed by glucose and galactose, whereas colorimetric quantification showed the presence of uronic acids. GC-MS analysis of the elicitor revealed the predominance of glucuronic acid and mannose. These results suggest that fragments of mucoran-type polysaccharides are the phytoalexin elicitors present in the spores of the saprobe M. ramosissimus. Our results also indicate for the first time that soybean cotyledon tissues can recognize fragments of glucuronic-acid heteropolymers as phytoalexin elicitors. (AU) | |
| FAPESP's process: | 98/05124-8 - Conservation and sustainable use of the plant biodiversity from the cerrado and Atlantic Forest: the storage of carbohydrates and their role on the adaptation and maintainance of plants in their natural environment |
| Grantee: | Marcos Silveira Buckeridge |
| Support Opportunities: | BIOTA-FAPESP Program - Thematic Grants |