top of page

My research aims to dissect the molecular control of plant stem cell dynamics. I use Arabidopsis shoot apical meristem as a model to study the regulation of plant stem cell division and cell wall structure.

Building of cell walls in Arabidopsis shoot apical meristem

​Through systematic cell wall linkage analysis, RNA sequencing, and mRNA in situ hybridisation, I generated a global  landscape of cell wall composition and gene expression patterns of cell wall biosynthetic enzymes (Figure 1) (Yang et al., 2014, Current Biology), providing a framework for more detailed studies on the mechanical property and biological functions of cell wall in plant stem cells. The dataset has also contributed to the launching of Image Data Resource (IDR) (Williams et al., 2017). ​

Fig 1.jpg

Figure 1. Regulation of meristem morphogenesis by cell wall synthases. The expression patterns of glycosyltransferase genes at the shoot apex. The GTs are classified into five patterns according to their mRNA distribution. Type 1: uniform distribution across the apex; type 2: primordia-specific enrichment; type 3: intense scattered spots; type 4: both spotted and general apical enrichment; type 5: not classified in the above.

Precision of stem cell division through mRNA nuclear retention

​To precisely analyze mRNA expression dynamics in both tissue and cellular levels, I developed double mRNA fluorescence in situ hybridisation and combined it with immunocytochemistry to simultaneously detect the same gene’s mRNA and protein. With this technology, I have identified mRNAs that are specifically sequestered inside the nucleus to block protein translation (Figure 2). These mRNAs include genes that regulate cell cycle (Yang et al., 2017, Molecular Cell) and other biological processes such as cell wall modification, implying a new mechanism for gene expression control through mRNA nuclear sequestration (F1000Prime Recommendations by Kalsotra & Seimetz, 2018, and Roeder & Robinson, 2018).

Fig 2'.jpg

Figure 2. Control of gene expression and cell division by mRNA nuclear sequestration. Co-localization of CDC20 and CYCB1;1 to CYCB1;4 mRNAs in the same cells by RNA FISH. CDC20 mRNAs (in red) are constrained inside the nucleus, while CYCB1;1-CYCB1;4 mRNAs (in green) are exported into the cytoplasm.

Maintenance of stem cell population by cytokinin

Plant cell division is regulated by both developmental signals and environmental cues. How cytokinin stimulates cell division is a long-standing question that is still poorly understood. My research also involves the molecular mechanism of cytokinin activated cell division.

-------------------------------------------------------------------------------------------------------------------------------------

Rice is a crop plant that supports more than half of the world population, it has also been adopted as monocot model by plant researchers for many years. My PhD research focused on the molecular mechanism(s) underlying rice important agronomical traits, including shoot architecture, seed development, and disease resistance.

  • By combing genetic, molecular and cellular approaches, I identified and functionally characterized the first plant Class II formin gene Bent Uppermost Internode 1 (BUI1) that plays essential roles in actin cytoskeleton organization, cell expansion and rice shoot morphogenesis (Figures 3A-3C) (Yang et al., 2011, Plant Cell).

​​

  • My work on rice seed development reveals a novel cytochrome P450 monooxygenase Giant Embryo (GE) that is specifically expressed in embryo epidermis to coordinate embryo and endosperm development (Figures 1D-1F) (Yang et al., 2013, Molecular Plant).

 

  • I have been investigating the crosstalk between plant growth and immunity. We focused on negative regulators of rice disease response, including two GDSL lipases that modulate lipid homeostasis (Gao et al., 2017, PLOS Pathogens) and a calcium sensor Resistance of Diseases 1 (ROD1).

 

1.jpg

Figure 3. Molecular control of rice shoot and seed development. (A) Shoot phenotype of wild-type and the bui1 mutant. (B) Actin cytoskeleton organization is disrupted in bui1. (C) BUI1 promotes actin polymerization. (D) Enlarged embryos in the ge mutant. (E) Tissue-specific expression of GE in the embryo epidermal cells, as revealed by mRNA in situ hybridisation (top panel) and promoter reporters (bottom panel).  (F) Arabidopsis GE homologue CYP78A10 is also expressed in developing seeds and controls seed size.

bottom of page