Professional Experiences 

National Chung Hsing University, Institute of Molecular Biology, Assistant Professor, 2020/08-.

National Institute of Advanced Industrial Science and Technology (Japan), Bioproduction Research Institute, Invited Guest Researcher, 2019/10-.

National Cheng Kung University, Institute of Tropical Plant Sciences and Microbiology, Assistant Professor, 2019/08-2020/07.

Saitama University (Japan), Area of Green and Environmental Innovation, Assistant Professor, 2014/04-2019/07.

Saitama University (Japan), Department of Biochemistry and Molecular Biology, Assistant Professor, 2014/04-2019/07.

National Institute of Advanced Industrial Science and Technology (Japan), Bioproduction Research Institute, Invited Collaborative researcher, 2014/04-2019/09.

National Institute of Advanced Industrial Science and Technology (Japan) Bioproduction Research Institute, JSPS Fellow, 2012/06-2014/03.

National Institute of Advanced Industrial Science and Technology (Japan) Bioproduction Research Institute, AIST Visiting Researcher, 2011/05-2012/05.

Academia Sinica, Agriculture Biotechnology Research Center, Postdoctoral Fellow, 2006/10-2010/12.

National Cheng Kung University, Department of Life Sciences Postdoctoral, Fellow, 2006/05-2006/07.

National University of Tainan, Center for General Education, Adjunct Lecturer, 2006/02-2006/07.

Shu-Te University, College of Liberal Education, Adjunct Lecturer, 2003/08-2004/07.

Research interests 

I mainly focus on two research projects of “Plant nutrient homeostasis and adaptive mechanism” and “Genomics and functional genomics of orchids”. In addition, I pay some attention to “Identification of plant growth-promoting microbes by Metagenomic approach” and “Identification of plant transcription factors that regulate biotic and abiotic stress tolerance”.

1.Plant nutrient homeostasis and adaptive mechanism

In this project, I mainly investigate transcriptional regulation in response to nutrient deficiency, heavy metal stress and acid soil stress through screening of Arabidopsis and rice CRES-T (Chimeric REpressor gene Silencing Technology) plants. The CRES-T can convert a transcriptional activator into a strong repressor by fusion with the plant-specific repression domain SRDX (superman repression domain X) leading to dominant repression of the target genes. The resultant transgenic plants exhibit phenotypes similar to those of the multiple knockout mutants of the manipulated transcription factors (TFs) and their functionally redundant TFs. Functional redundancy of TFs often interferes with efforts to identify their functions when a single TF gene is knocked out (as shown in the following figure). The CRES-T can overcome this drawback (Hiratsu et al., 2003, Plant J 34: 733-739). So far, around 1,800 Arabidopsis CRES-T lines and 1,200 rice CRES-T lines have been created for functional studies. A number of orchid CRES-T constructs have been created and the others will be continued in future. Furthermore, we modify the CRES-T system and replace SRDX with VP16 domain, an activation domain from the herpes simplex virus, when TFs act as repressors. Overexpression of VP16 domain can activate downstream gene expression and shows phenotypes similar to the multiple knock-out mutants of the target repressors and their redundant genes. To efficiently identify upstream TFs of target genes or interacting proteins of target TFs, a modified yeast one-/two-hybrid (Y1/2H) system was developed in that a whole cDNA library is replaced with a TF cDNA library to reduce false-positive signals. In addition, the modified Y1/2H is coupled with a robotic system to produce high-efficient and high-throughput screenings.

(a) Identification and characterization of transcription factors regulating plant nutrient deficiency responses: focus on phosphate and nitrogen deficiency

Several potential candidate lines with hypersensitivity or tolerance to phosphate (Pi) or nitrogen (N) deficiency were identified and under characterized. We preferentially investigate the tolerant candidate lines with long primary root lengths under low-Pi treatment. Interestingly, several lines show Pi deficiency-tolerant phenotype even when grown on the medium without Pi. In addition, the double mutant of one candidate TF gene which doesn’t possess lateral roots also showed tolerance to Pi deficiency, indicating that the tolerance does not result from increase of external Pi uptake and may be related to internal Pi utilization or recycling. We are interested in identification of these candidate lines for future application.

(b) Molecular and physiological studies of Arabidopsis CRES-T lines with altered sensitivities to aluminum and acid soil stress

Due to severe deficiencies of several important nutrients, such as P and N, and toxicity of heavy metals, such as Al and Fe, in acid soils, we also screened CRES-T lines responsive to acid-soil stress by artificial medium (with low pH only or with low pH and Al) and andosol (natural acid soil in Tohoku area, Japan). Several candidate lines with altered response to Al stress and acid soil stress were identified and under characterized.

(c) Identification of phosphate starvation-related transcription factors through bioinformatics tools

Considering that the insoluble organic Pi accounts for 80% of the total Pi in natural soils and phytate is the major form of those organic Pi, we aim to identify transcription factors which regulate phytate utilization genes, such as purple acid phosphatase (PAP) genes, through bioinformatics (collaborate with Professor Wen-Chih Chang, National Cheng-Kung University) and screening of CRES-T lines. Transgenic plants with high utilization of phytate could contribute to reduce application of Pi fertilizers in the future. Furthermore, screening of CRES-T plants which can utilize other insoluble organic Pi will be proceeded in further studies. Moreover, we are also interested in identification of other Pi starvation-related transcription factors by bioinformatics analysis and characterization of their functions via CRES-T and VP16 lines.

(d) Chemical genetics study: Screening of CRES-T lines with altered response to chemicals which trigger phosphate starvation responses

Similar to CRES-T, chemical genetics can overcome problems associated with redundant signalling networks when bioactive molecules act as a general antagonist to inhibit multiple components in the network or as a specific agonist to activate a specific component of the network. My collaborators lead by Professor Laurent Nussaume (CEA, France), have isolated chemicals which can trigger or block Pi starvation responses from chemical library. We will conduct further research to identify transcription factors related to the networks responsive to these chemicals and comprehensively unravel biological processes in response to Pi deficiency.

Genomics and functional genomics of orchids

I am involved in "the International Orchid Genome Sequencing Project" and collaborate with several research teams from Belgium, Denmark, China, Japan and Taiwan. I am responsible to organize the Japanese team and currently collaborate with AIST, NARO, NIAST and Tohoku University. I am also one of the corresponding authors in the publication of orchid genomes.

(a) Genome sequencing of ornamental and medicinal orchids

We have completed the first genome sequencing of a medicinal orchid, Dendrobium, and published in "Scientific Reports" in 2016. Our team identified key genes involved in the biosynthesis of the medicinal polysaccharide in Dendrobium. The achievement would be helpful for the future development of Chinese medicine. In 2017, we published another sequenced genome of an ancestral orchid, Apostasia, in "Nature". The study provides new insights into the origins and evolution of the diverse and widespread orchid family and contributes to future breeding of commercial orchids. The genome sequencing of the achlorophyllous myco-heterotrophic orchids and the orchids important for food and cosmetic marketing have been completed and prepared for submission.

(b) Functional study of orchid transcription factors involved in development and stress responses through the CRES-T approach

One of my objects of involving in the orchid sequencing project is to investigate the unique properties, especially the nutrient utilization strategy, in orchids since many of them grew on nutrient-limited environments. I aim to identify and characterize orchid transcription factors involved in the regulation of flower and leaf development and responses to nutrient deficiency. So far, two collaborative papers related to flower development and fragrance production have been published and one manuscript related to leaf development has been submitted.

Honor 

The Japan Society for the Promotion of Science (JSPS) Fellowship, 2012.06-2014.06

AIST Visiting Researcher Fellowship, 2011.05-2012.05

Academia Sinica Postdoctoral Fellowship, 2009.01-2010.12

Academia Sinica Postdoctoral Fellowship, 2007.01-2008.12

The member of the Phi Tau Phi Scholastic Honor Society, 2006

The Best Poster Award: Symposium on Frontiers of Plant Science, Taiwan, 2009

The Best Poster Award: the 8th Annual ABRC Poster Competition, Taiwan, 2008

The Poster Award: the 24rd Annual Meeting of the Botanical Society, Taiwan, 2003

Course 

Molecular Biology (BS)

Advanced Molecular Biology (MS)

Methods in Molecular Biology

Plant Genomes and Gene Regulation

Current Topics in Plant Gene Transformation

Seminar

Review of Current Literature

The Vitality and Sustainability of Life