Ya-Yun Wang Associate Professor
Ph.D., Institute of Genome Sciences, National Yang-Ming
Specialty: Plant Molecular Genetics
Laboratory: Life Science Building R1006
Current Research Interests
How do NPF (Nitrate transporter 1/Peptide transporter Family) genes in Arabidopsis re-distribute nitrogen sources, plant hormones, and secondary metabolites in order to maintain growth and keep alive? What are the key features to determine the substrate specificity for peptide and nitrate in NPF?
In previous study, my study has shown that NPF2.9/NRT1.9 is expressed in the companion cells of root phloem (Figure 1), and more nitrate was detected in the shoots in nrt1.9 mutants, suggesting that NRT1.9 mediates the nitrate movement from xylem to phloem in roots. Indeed, more nitrate was detected root phloem sap (Figure 2). Therefore, in addition to NPF7.3/NRT1.5 and NPF7.2/NRT1.8, NPF2.9/ NRT1.9 also participate in the regulation of root-to-shoot nitrate transport. (Figure 3) In recent five years, many studies demonstrate that, besides nitrate and peptides, NPF can transport other diverse substrates, including phytohormones (auxin and jasmonate) and secondary metabolites (such as glucosinolates). And the expression of NPF genes are affected by many external stimuli. These data suggest that upon facing stimuli, NPF may re-distribute the substrates in order to adapt the changing environment. However, little is known about what are the roles of NPF in responding stresses.According to the public microarray data, we pick up several NPF genes that highly regulated by certain stimuli. The functions of the selected NPF will be analyzed using the approaches of genetics, physiology, and molecular biology. On the other hand, the substrate specificity will by assayed by Xenopus oocyte expression system. Taken all of the results, we may be able to get more insights about the plants’ responses to the surround environment. Welcome to join us to explore the beauty of plants!
Figure 1: [A~C] Histochemical localization of GUS activity in transgenic plants. [D~G] Confocal laser scanning microscope pictures of NRT1.9pro:NRT1.9-GFP transgenic plants. Arrowheads, the position of xylem axis; arrows, companion cells; asterisk, sieve element. Ep, epidermis; Co, cortex; En, endodermis; Pe, pericycle.
Figure 2: [C] Nitrate content of root phloem exudates in the wild type and nrt1.9 mutants. [D] Downward nitrate transport in the wild type and nrt1.9 mutants.
Figure 3: Regulation of root-to-shoot nitrate transport.
Y.-Y. Wang, Y.-H. Cheng, K.-E. Chen, and Y.-F. Tsay*. (2017) Nitrate transporter, sensing and use efficiency. Annu. Rev. Plant Biol. Submitted. (Co-first author)
Y. Li, J. Ouyang, Y.-Y Wang, R. Hu, K. Xia, J. Duan, Y. Wang, Y.-F. Tsay and M. Zhang (2015) Disruption of the rice nitrate transporter OsNPF2.2 hinders root-to-shoot nitrate transport and vascular development. Sci. Rep. 5: 9635-9644.
Y.-Y. Wang, P.-K. Hsu and Y. -F. Tsay* (2012) Uptake, allocation and signaling of nitrate. Trends Plant Sci. 17: 458-467.
Y.-Y. Wang and Y.-F. Tsay* (2011) Arabidopsis nitrate transporter NRT1.9 is important in phloem nitrate transport. Plant Cell. 23: 1945-1957.
H.-C. Hu,Y.-Y. Wang and Y.-F. Tsay* (2009) AtCIPK8, a CBL-interacting protein kinase, regulates the low-affinity phase of the primary nitrate response. Plant J. 57:264-78.
S. H. Lin, H. F. Kuo, G. Canivenc, C. S. Lin, M. Lepetit, P. K. Hsu, P. Tillard, H. L. Lin, Y.-Y. Wang, C.-B. Tsai and Y.-F. Tsay* (2008) Mutation of the Arabidopsis NRT1:5 nitrate transporter causes defective root-to-shoot nitrate transport. Plant Cell 20: 2514-2528.