The Chromatin Remodeling Factor <i>BrCHR39</i> Targets DNA Methylation to Positively Regulate Apical Dominance in <i>Brassica rapa</i>
Wei Zhu,
Zhengqing Xie,
Zhenni Chu,
Yakun Ding,
Gongyao Shi,
Weiwei Chen,
Xiaochun Wei,
Yuxiang Yuan,
Fang Wei,
Baoming Tian
Affiliations
Wei Zhu
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Zhengqing Xie
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Zhenni Chu
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Yakun Ding
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Gongyao Shi
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Weiwei Chen
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Xiaochun Wei
Institute of Horticulture, Henan Academy of Agricultural Sciences, Graduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
Yuxiang Yuan
Institute of Horticulture, Henan Academy of Agricultural Sciences, Graduate T&R Base of Zhengzhou University, Zhengzhou 450002, China
Fang Wei
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Baoming Tian
Henan International Joint Laboratory of Crop Gene Resource and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
The SHPRH (SNF2, histone linker, PHD, RING, helicase) subfamily belonging to ATP-dependent chromatin remodeling factor is the effective tumor-suppressor, which can polyubiquitinate PCNA (proliferating cell nuclear antigen) and participate in post-replication repair in human. However, little is known about the functions of SHPRH proteins in plants. In this study, we identified a novel SHPRH member BrCHR39 and obtained BrCHR39-silenced transgenic Brassica rapa. In contrast to wild-type plants, transgenic Brassica plants exhibited a released apical dominance phenotype with semi-dwarfism and multiple lateral branches. Furthermore, a global alteration of DNA methylation in the main stem and bud appeared after silencing of BrCHR39. Based on the GO (gene ontology) functional annotation and KEGG (Kyoto encyclopedia of genes and genomes) pathway analysis, the plant hormone signal transduction pathway was clearly enriched. In particular, we found a significant increase in the methylation level of auxin-related genes in the stem, whereas auxin- and cytokinin-related genes were hypomethylated in the bud of transgenic plants. In addition, further qRT-PCR (quantitative real-time PCR) analysis revealed that DNA methylation level always had an opposite trend with gene expression level. Considered together, our findings indicated that suppression of BrCHR39 expression triggered the methylation divergence of hormone-related genes and subsequently affected transcription levels to regulate the apical dominance in Brassica rapa.
