In:
Plant Physiology, Oxford University Press (OUP), Vol. 139, No. 4 ( 2005-12-01), p. 1881-1889
Kurzfassung:
Nodules are formed on legume roots as a result of signaling between symbiotic partners and in response to the activities of numerous genes. We cloned fragments of differentially expressed genes in spot-inoculated soybean (Glycine max) roots. Many of the induced clones were similar to known genes related to oxidative stress, such as thioredoxin and β-carotene hydroxylase. The deduced amino acid sequences of full-length soybean cDNAs for thioredoxin and β-carotene hydroxylase were similar to those in other species. In situ RNA hybridization revealed that the thioredoxin gene is expressed on the pericycle of 2-d-old nodules and in the infected cells of mature nodules, suggesting that thioredoxin is involved in nodule development. The thioredoxin promoter was found to contain a sequence resembling an antioxidant responsive element. When a thioredoxin mutant of yeast was transformed with the soybean thioredoxin gene it became hydrogen peroxide tolerant. These observations prompted us to measure reactive oxygen species levels. These were decreased by 3- to 5-fold in 7-d-old and 27-d-old nodules, coincident with increases in the expression of thioredoxin and β-carotene hydroxylase genes. Hydrogen peroxide-producing regions identified with cerium chloride were found in uninoculated roots and 2-d-old nodules, but not in 7-d-old and 27-d-old nodules. RNA interference-mediated repression of the thioredoxin gene severely impaired nodule development. These data indicate that antioxidants such as thioredoxin are essential to lower reactive oxygen species levels during nodule development.
Materialart:
Online-Ressource
ISSN:
1532-2548
,
0032-0889
DOI:
10.1104/pp.105.067884
Sprache:
Englisch
Verlag:
Oxford University Press (OUP)
Publikationsdatum:
2005
ZDB Id:
2004346-6
ZDB Id:
208914-2
SSG:
12
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