| Name: |
| Zonglie Hong |
| Title: |
| Assistant Professor |
| Degree: |
| Ph.D. University of Novi Sad |
| Phone: |
| (208) 885-5464 |
| Fax: |
| (208) 885-6518 |
| Email: |
| zhong@uidaho.edu |
| Lab/Office Location: |
| Gibb Hall, Room 130 |
| Lab Phone: |
| (208) 885-4235 |
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| Research Interests: |
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Research in my laboratory focuses on the characterization of genes and proteins involved in callose synthesis during flower
development and cell plate formation in plants. Callose, a beta-1,3-glucan, is an important constituent of intact plants. It is
required for the formation of the cell plate, plasmodesmata, tracheids, pollen and pollen tube, and root hairs. It is also produced
in plant cells in response to wounding, heavy metal treatment and pathogen infection. During cytokinesis in plant cells,
Golgi-derived vesicles are transported to the center of the dividing cell, where they fuse with each other to form a dynamic tubular
network. This fragile structure is first filled with callose, a beta-1,3-glucan, which provides a spreading force to convert the
tubular network into a plate. Cellulose (beta-1,4-glucan) and other cell wall components are then synthesized and deposited at the
expanding cell plate, leading to the formation of a new cell wall. In the anthers of developing flowers, a callose wall is
synthesized between the plasma membrane and the primary cell wall of the pollen mother cells. After meiosis, the microspore tetrads
are encapsulated in the callose wall. Callose is also the major polysaccharide constituent of the pollen tube wall. We intend to
identify and characterize new components of the callose synthase (CalS) complex from the cell plate of dividing cells and from the
plasma membrane of differentiated tissues including roots and flowers. These studies are carried out in transgenic plants and cell
lines of model plants Arabidopsis and tobacco. The experimental approach taken in my laboratory includes biochemistry, molecular
biology, cell and developmental biology, genetics, genomics and proteomics. These studies may lead to the identification of novel
protein kinases, small and large GTPases, proteases and other proteins that regulate callose synthesis in plants.
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A model of callose synthase complex in plants. CalS1 and CalS5 each contain 16 transmembrane helices which are
clustered into two regions separated by a large central loop. UDP-glucose transferase (UGT1) and sucrose synthase
(SuSy), which provide UDP-glucose (UDP-G) from the breakdown of sucrose, could be part of the complex.
Rho-like small GTP-binding protein (Rop), protein kinases and proteases may also play a regulatory role in
callose synthesis.
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| Selected Publications: |
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Verma DPS, Hong Z (2005) The ins and outs in membrane dynamics: Tubulation and vesiculation. Trends Plant Sci. 10: 159-165.
Dong X, Hong Z, Sivaramakrishnan M, Mahfouz M, Verma DPS (2005a) Callose synthase (CalS5) is required for exine formation during microgametogenesis and pollen viability in Arabidopsis. Plant J. 42: 315-328.
Hong Z, Bednarek S, Blumwald E, Hwang I, Jurgens G, Menzel D, Osteryoung K, Raikhel N, Shinozaki K, Tsutsumi N, Verma DPS (2003) A unified nomenclature for Arabidopsis dynamin-related large GTPases based on homology and possible functions. Plant Mol. Biol. 53: 261-265.
Hong Z, Geisler-Lee J, Zhang Z, Verma DPS (2003) Phragmoplastin dynamics: multiple forms, microtubule association and their roles in cell plate formation in plants. Plant Mol. Biol. 53: 297-312. (including the Cover Picture of the Journal)
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