1. Suppression of the Arabidopsis cinnamoyl-CoA reductase 1-6 intronic T-DNA mutation by epigenetic modification.
- Author
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Wouters M, Bastiaanse H, Rombauts S, de Vries L, De Pooter T, Strazisar M, Neutelings G, Vanholme R, and Boerjan W
- Subjects
- Lignin metabolism, Mutation genetics, DNA, Bacterial genetics, Epigenesis, Genetic, Glucosyltransferases metabolism, Arabidopsis metabolism, Arabidopsis Proteins genetics, Arabidopsis Proteins metabolism
- Abstract
Arabidopsis (Arabidopsis thaliana) transfer DNA (T-DNA) insertion collections are popular resources for fundamental plant research. Cinnamoyl-CoA reductase 1 (CCR1) catalyzes an essential step in the biosynthesis of the cell wall polymer lignin. Accordingly, the intronic T-DNA insertion mutant ccr1-6 has reduced lignin levels and shows a stunted growth phenotype. Here, we report restoration of the ccr1-6 mutant phenotype and CCR1 expression levels after a genetic cross with a UDP-glucosyltransferase 72e1 (ugt72e1),-e2,-e3 T-DNA mutant. We discovered that the phenotypic recovery was not dependent on the UGT72E family loss of function but due to an epigenetic phenomenon called trans T-DNA suppression. Via trans T-DNA suppression, the gene function of an intronic T-DNA mutant was restored after the introduction of an additional T-DNA sharing identical sequences, leading to heterochromatinization and splicing out of the T-DNA-containing intron. Consequently, the suppressed ccr1-6 allele was named epiccr1-6. Long-read sequencing revealed that epiccr1-6, not ccr1-6, carries dense cytosine methylation over the full length of the T-DNA. We showed that the SAIL T-DNA in the UGT72E3 locus could trigger the trans T-DNA suppression of the GABI-Kat T-DNA in the CCR1 locus. Furthermore, we scanned the literature for other potential cases of trans T-DNA suppression in Arabidopsis and found that 22% of the publications matching our query report on double or higher-order T-DNA mutants that meet the minimal requirements for trans T-DNA suppression. These combined observations indicate that intronic T-DNA mutants need to be used with caution since methylation of intronic T-DNA might derepress gene expression and can thereby confound results., Competing Interests: Conflict of interest statement. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© American Society of Plant Biologists 2023. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
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