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An Arabidopsis histone H2A mutant is deficient in Agrobacterium T-DNA integration

Author:
Mysore, K.S., Nam, J., Gelvin, S.B.
Source:
Proceedings of the National Academy of Sciences of the United States of America 2000 v.97 no.2 pp. 948-953
ISSN:
0027-8424
Subject:
Arabidopsis thaliana, transgenic plants, genetic transformation, roots, Agrobacterium tumefaciens, histones, mutants, gene expression, reporter genes, nucleotide sequences, genes, genetic complementation, genetic recombination, transfer DNA
Abstract:
Agrobacterium tumefaciens genetically transforms plant cells by transferring a portion of the bacterial Ti-plasmid, the T-DNA, to the plant and integrating the T-DNA into the plant genome. Little is known about the T-DNA integration process, and no plant genes involved in integration have yet been identified. We characterized an Arabidopsis mutant generated by T-DNA insertional mutagenesis, rat5, that is resistant to Agrobacterium root transformation. rat5 contains two copies of T-DNA integrated as a tandem direct repeat into the 3' untranslated region of a histone H2A gene, upstream of the polyadenylation signal sequence. Transient and stable beta-glucuronidase expression data and assessment of the amount of T-DNA integrated into the genomes of wild-type and rat5 Arabidopsis plants indicated that the rat5 mutant is deficient in T-DNA integration. We complemented the rat5 mutation by expressing the RAT5 histone H2A gene in the mutant plant. Overexpression of RAT5 in wild-type plants increased Agrobacterium transformation efficiency. Furthermore, transient expression of a RAT5 gene from the incoming T-DNA was sufficient to complement the rat5 mutant and to increase the transformation efficiency of wild-type Arabidopsis plants.
Agid:
2357755