Jaw-1D: a gain-of-function mutation responsive to paramutation-like induction of epigenetic silencing. (20th October 2018)

• Record Type: Journal Article
• Authors: Jiang, Wen; Li, Zhongfei; Yao, Xiaozhen; Zheng, Binglian; Shen, Wen-Hui; Dong, Aiwu
• Is Part Of: Journal of experimental botany. Volume 70:Number 2(2019)
• Page Start: 459
• Page End: 468
• Publication Date: 2018-10-20
• Subjects: Arabidopsis thaliana -- DNA methylation -- epigenetic silencing -- histone methylation -- jaw-1D -- paramutation; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/ery365
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : An Arabidopsis gain-of-function T-DNA insertion mutant, jaw-1D, has an unexpected paramutation phenomenon caused by transgenic SALK mutant lines with multi-copy tandem T-DNA repeats. Abstract: The Arabidopsis thaliana gain-of-function T-DNA insertion mutant jaw-1D produces miR319A, a microRNA that represses genes encoding CIN-like TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTORs (TCPs), a family of transcription factors that play key roles in leaf morphogenesis. In this study, we show that jaw-1D is responsive to paramutation-like epigenetic silencing. A genetic cross of jaw-1D with the polycomb gene mutant curly leaf-29 ( clf-29 ) leads to attenuation of the jaw-1D mutant plant phenotype. This induced mutation, jaw-1D*, was associated with down-regulation of miR319A, was heritable independently from clf-29, and displayed paramutation-like non-Mendelian inheritance. Down-regulation of miR319A in jaw-1D* was linked to elevated levels of histone H3 lysine 9 dimethylation and DNA methylation at the CaMV35S enhancer located within the activation-tagging T-DNA of the jaw-1D locus. Examination of 21 independent T-DNA insertion mutant lines revealed that 11 could attenuate the jaw-1D mutant phenotype in a similar way to the paramutation induced by clf-29 . These paramutagenic mutant lines shared the common feature that their T-DNA insertion was present as multi-copy tandem repeats and contained high levels of CG and CHG methylation. Our results provide important insights into paramutation-like epigenetic silencing, and caution against the use of jaw-1D in genetic interaction studies.