Analysis of the Binding of Expansin Exl1, from Pectobacterium carotovorum, to Plant Xylem and Comparison to EXLX1 from Bacillus subtilis
| Autor: | Jose M. Moran-Mirabal, Christopher D. Wood, Mabel Rodríguez, Omar Eduardo Tovar-Herrera, Lorenzo Segovia, Nina Pastor, Adán Guerrero, Claudia Martínez-Anaya, Xochitl Alvarado-Affantranger, Miguel Olarte-Lozano, Jimmy Andrés Sampedro-Guerrero, Raúl Pinto-Cámara |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine biology Chemistry General Chemical Engineering fungi food and beverages Xylem Pectobacterium carotovorum General Chemistry Bacillus subtilis biology.organism_classification 01 natural sciences Article lcsh:Chemistry Cell wall 03 medical and health sciences Expansin 030104 developmental biology lcsh:QD1-999 Biophysics Secondary cell wall Vascular tissue Intracellular 010606 plant biology & botany |
| Zdroj: | ACS Omega ACS Omega, Vol 3, Iss 6, Pp 7008-7018 (2018) |
| ISSN: | 2470-1343 |
| Popis: | The plant xylem is a preferred niche for some important bacterial phytopathogens, some of them encoding expansin proteins, which bind plant cell walls. Yet, the identity of the substrate for bacterial expansins within the plant cell wall and the nature of its interaction with it are poorly known. Here, we determined the localization of two bacterial expansins with differing isoelectric points (and with differing binding patterns to cell wall extracts) on plant tissue through in vitro fluorophore labeling and confocal imaging. Differential localization was observed, in which Exl1 from Pectobacterium carotovorum located into the intercellular spaces between xylem vessels and adjacent cells of the plant xylem, whereas EXLX1 from Bacillus subtilis bound cell walls of most cell types. In isolated vascular tissue, however, both PcExl1 and BsEXLX1 preferentially bound to tracheary elements over the xylem fibers, even though both are composed of secondary cell walls. Fluorescence correlation spectroscopy, employed to analyze the interaction of expansins with isolated xylem, indicates that binding is governed by more than one factor, which could include interaction with more than one type of polymer in the fibers, such as cellulose and hemicellulose or pectin. Binding to different polysaccharides could explain the observed reduction of cellulolytic and xylanolytic activities in the presence of expansin, possibly because of competition for the substrate. Our findings are relevant for the comprehensive understanding of the pathogenesis by P. carotovorum during xylem invasion, a process in which Exl1 might be involved. |
| Databáze: | OpenAIRE |
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