Xuehua Zhong

Epigenetic regulation of plant genome integrity, developmental and environmental interaction

Years at WID

2013 - present

Education

  • B.S., Wuhan University, China M.S., Wuhan University, China
  • Ph.D., The Ohio State University
  • Postdoctoral Research, University of California, Los Angeles

Research Description

Epigenetic Regulation in Plant Growth and Development

Epigenetic regulation is a process whereby genes can inherit different states of activity in the absence of any changes in the DNA sequences. One such epigenetic system involves the addition of a chemical mark on DNA, so-called DNA methylation, which causes silencing of underlying genes. DNA methylation-based gene silencing can be very stable and in many cases mitotically heritable. Epigenetic modifications of histones (proteins that package and organize DNA), such as methylation and acetylation, play crucial roles in regulating all DNA-dependent processes including transcription, replication, DNA repair and recombination in diverse organisms. Mis-regulation and abnormalities of histone modifications are often observed in plant and animal diseases.

Given the great importance of epigenetic regulation of gene expression in many aspects of biology, ranging from genome integrity, imprinting, cellular differentiation, normal growth and development, disease formation, to potential biotechnological applications, our research goal is to understand the fundamental mechanisms of chromatin-based gene regulation. We study how various chromatin factors are recruited to chromatin to “read” and ‘translate” epigenetic information into differential gene expression patterns under normal growth and development as well as stress conditions. Knowledge gained from such studies should have high and broad impacts on our understanding of how distinct chromatin modifications coordinate with each other to regulate gene expression critical for diverse biological processes. They may also contribute to the development of new tools for applied research. Some outstanding questions we are interested in answering are:

  • How does dynamic epigenetic modification regulate gene expression for proper growth and development?
  • How do chromatin alternations lead to changes in stable gene expressions?
  • How do different developmental and environmental stimuli influence the chromatin dynamics?
  • How are chromatin modifications established and maintained under stress conditions?
  • Are altered chromatin structures stable and inheritable?

To address these questions, we use Arabidopsis thaliana as our main experimental model system because of its amenability to genetic manipulations, small genome, availability and viability of most epigenetic mutants. Experimentally, we will use a combination of molecular, genetic, genomic, proteomic, biochemical and structural approaches.

Honors

  • NIH Ruth L. Kirschstein National Research Service Award (2011)
  • NSF Faculty Early Career Development (CAREER) Award (2015)
  • Alfred Toepfer Faculty Fellow Award by Alexander von Humboldt Foundation (2016)
  • NIH Maximizing Investigators’ Research Award (2017)

Selected Publications

  • Histone Lysine-to-Methionine Mutations Reduce Histone Methylation and Cause Developmental Pleiotropy. Sanders D, Qian S, Fieweger R, Lu L, Dowell JA, Denu JM, Zhong X. Plant Physiology. 2017, 173(4):2243-2252.
  • POWERDRESS interacts with HISTONE DEACETYLASE 9 to promote aging in Arabidopsis. Chen X, Lu L, Mayer KS, Scalf M, Qian S, Lomax A, Smith LM, Zhong X. Elife. 2016. pii: e17214. doi: 10.7554/eLife.17214.
  • Comparative epigenomics: a powerful tool to understand the evolution of DNA methylation. Zhong X. New Phytologist. 2016, 21: 76-80. • High-resolution mapping of H4K16 and H3K23 acetylation reveals conserved and unique distribution patterns in Arabidopsis and rice. Lu L, Chen X, Sanders D, Qian S, Zhong X. Epigenetics. 2015, 10: 1044-53.
  • DOMAINS REARRANGED METHYLTRANSFERASE3 controls DNA methylation and regulates RNA polymerase V transcript abundance in Arabidopsis. Zhong X* #, Hale CJ*, Nguyen M, Ausin I, Groth M, Hetzel J, Vashisht AA, Henderson IR, Wohlschlegel JA, Jacobsen SE#. PNAS. 2015, 112: 911-6. #Corresponding author; *Equal contribution
  • Molecular mechanism of action of plant DRM de novo DNA methyltransferases. Zhong X*, Du J*, Hale CJ, Gallego-Bartolome J, Feng S, Vashisht AA, Chory J, Wohlschlegel JA, Patel DJ, Jacobsen SE. Cell, 2014, 157: 1050-60. *Equal contribution
  • SRA- and SET-domain-containing proteins link RNA Polymerase V occupancy to DNA methylation. Johnson LM, Du J, Hale CJ, Bischof S, Feng S, Chodavarapu RK, Zhong X, Marson G, Pellegrini M, Segal DJ, Patel DJ, Jacobsen SE. Nature. 2014, 507:124-8.
  • The histone variant H2A.W marks heterochromatin and promotes chromatin condensation in Arabidopsis. Yelagandula R, Stroud H, Holec S, Zhou K, Feng S, Zhong X, Muthurajan UM, Nie X, Luger K, Jacobsen SE, Berger F. Cell. 2014 158: 98-109.
  • Dual binding of chromomethylase domains to H3K9me2-containing nucleosomes directs DNA methylation in plants. Du J*, Zhong X*, Bernatavichute YV, Stroud H, Feng S, Caro E, Vashisht AA, Terragni J, Chin HG, Tu A, Hetzel J, Wohlschlegel JA, Pradhan S, Patel DJ, Jacobsen SE. Cell. 2012, 151: 167-80. *Equal contribution
  • DDR complex facilitates genome-wide association of RNA polymerase V to promoters and evolutionarily young transposons. Zhong X*, Hale CJ*, Law JA, Johnson LM, Feng S, Tu A, Jacobsen SE. Nat Struct & Mol Biol. 2012, 19: 870-75. *Equal contribution

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