| Autor: |
Soupène, E, Foussard, M, Boistard, P, Truchet, G, Batut, J |
| Zdroj: |
Proceedings of the National Academy of Sciences of the United States of America; April 1995, Vol. 92 Issue: 9 p3759-3763, 5p |
| Abstrakt: |
The symbiotic pattern of expression of Rhizobium meliloti N2-fixation genes is tightly coupled with the histological organization of the alfalfa root nodule and thus is under developmental control. N2-fixation gene expression is induced very sharply at a particular zone of the nodule called interzone II-III that precedes the zone where N2 fixation takes place. We show here that this coupling can be disrupted, hereby resulting in ectopic expression of N2-fixation genes in the prefixing zone II of the nodule. Uncoupling was obtained either by using a R. meliloti strain in which a mutation rendered N2-fixation gene expression constitutive with respect to oxygen in free-living bacterial cultures or by placing nodules induced by a wild-type R. meliloti strain in a microoxic environment. These results implicate oxygen as a key determinant of the symbiotic pattern of N2-fixation gene expression. |
| Databáze: |
Supplemental Index |
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