title: Epigenetic suppression of T-DNA insertion mutants in Arabidopsis.
abstract: T-DNA insertion mutants have been widely used to define gene functions in Arabidopsis and in other plants. Here, we report an unexpected phenomenon of epigenetic suppression of T-DNA insertion mutants in Arabidopsis. When the two T-DNA insertion mutants, yuc1-1 and ag-TD, were crossed together, the defects in all of the ag-TD plants in the F2 population were partially suppressed regardless of the presence of yuc1-1. Conversion of ag-TD to the suppressed ag-TD (named as ag-TD*) did not follow the laws of Mendelian genetics. The ag-TD* could be stably transmitted for many generations without reverting to ag-TD, and ag-TD* had the capacity to convert ag-TD to ag-TD*. We show that epigenetic suppression of T-DNA mutants is not a rare event, but certain structural features in the T-DNA mutants are needed in order for the suppression to take place. The suppressed T-DNA mutants we observed were all intronic T-DNA mutants and the T-DNA fragments in both the trigger T-DNA as well as in the suppressed T-DNA shared stretches of identical sequences. We demonstrate that the suppression of intronic T-DNA mutants is mediated by trans-interactions between two T-DNA insertions. This work shows that caution is needed when intronic T-DNA mutants are used.
authors.affiliation: Section of Cell and Developmental Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA.
authors.forename: Yangbin
authors.initials: Y
authors.lastname: Gao
authors.forename: Yunde
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D026342:AGAMOUS Protein, Arabidopsis / Q000235:genetics / Q000378:metabolism; D000483:Alleles; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D044127:Epigenesis, Genetic / Q000235:genetics*; D020868:Gene Silencing; D056426:Genetic Loci / Q000235:genetics; D007438:Introns / Q000235:genetics; D007612:Kanamycin / Q000494:pharmacology; D016254:Mutagenesis, Insertional / Q000235:genetics*; D010105:Oxygenases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D026342:AGAMOUS Protein, Arabidopsis; D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018076:DNA, Complementary; D012333:RNA, Messenger; C036483:T-DNA; D007612:Kanamycin; D010105:Oxygenases; C422746:YUC protein, Arabidopsis