Tai-ping Sun, Professor  

Tai-ping Sun

The diterpenoid phytohormone gibberellin (GA) plays pivotal roles in regulating growth and development throughout the life cycle of higher plants.  Mutations affecting GA biosynthesis or GA response were the key to control plant stature in wheat and rice that led to dramatically increased grain yield and contributed greatly to the success of the ‘Green Revolution’ in the 1960s.  By multi-faceted approaches using the reference plant Arabidopsis, my lab has made major breakthroughs in elucidating the sites and regulatory mechanisms of GA biosynthesis, and the conserved molecular events of GA perception and the early GA signaling pathway.  We identified the nuclear transcriptional regulators DELLA proteins, which function as master growth repressors by inhibiting all aspects of GA responses.  Binding of GA to its nuclear receptor GID1 enhances the GID1-DELLA interaction, which in turn leads to the rapid proteolysis of DELLA through the ubiquitin-proteasome pathway, and allows transcriptional reprogramming of GA-responsive genes.  We and other researchers further showed that GA-GID1-DELLA is a key regulatory module that controls plant growth by integrating internal developmental cues, and external biotic and abiotic signals (light, cold, salt and pathogen stresses).  DELLA proteins play a central role in these processes via direct protein-protein interactions with key transcription factors.  Our recent studies using genetic and physiological analyses together with chemical biology methods indicate that DELLA’s binding affinity to interacting proteins are oppositely regulated by two novel O-linked glycosylations on specific Ser/Thr residues: O-linked N-acetylglucosamine (O-GlcNAc) modification reduces DELLA activity, whereas O-fucosylation enhances DELLA activity.  We are investigating the global functions of O-GlcNAcylation and O-fucosylation in regulating plant development.

Education:
Ph.D., Duke University, 1987
B.S., National Tsing Hua University (Taiwan), 1980

Office Location: 3104 French Family Science Center, Durham, NC 27708
Email Address: tai.ping.sun@duke.edu

Specialties:
Cell and Molecular Biology
Developmental Biology
Genetics

Research Categories: Mechanisms of phytohormone controlled growth and development

Research Description: The diterpenoid phytohormone gibberellin (GA) plays pivotal roles in regulating growth and development throughout the life cycle of higher plants. Mutations affecting GA biosynthesis or GA response were the key to control plant stature in wheat and rice that led to dramatically increased grain yield and contributed greatly to the success of the ‘Green Revolution’ in the 1960s. Although the GA biosynthetic pathway had been characterized biochemically, little was known about the sites of GA production and the mode of GA action. By multi-faceted approaches using the model system Arabidopsis, my lab has made major breakthroughs in revealing the sites and regulatory mechanisms of GA biosynthesis. We also elucidated the conserved molecular events of GA perception and the early GA signaling pathway. We identified the nuclear transcriptional regulators DELLA proteins, which function as master growth repressors by inhibiting all aspects of GA responses. Binding of GA to its nuclear receptor GID1 enhances the GID1-DELLA interaction, which in turn leads to the rapid proteolysis of DELLA through the ubiquitin-proteasome pathway, and allows transcriptional reprogramming of GA-responsive genes. We and other researchers further showed that GA-GID1-DELLA is a key regulatory module that controls plant growth by integrating internal developmental cues, and external biotic and abiotic signals (light, cold, salt and pathogen stresses). Surprisingly, we recently found that DELLA directly interacts with multiple classes of key regulatory proteins in other signaling pathways. Our work is revealing the complex regulatory network between the GA pathway and other pathways to control plant growth and development.

Representative Publications   (More Publications)   (search)

  1. Zhang, ZL; Ogawa, M; Fleet, CM; Zentella, R; Hu, J; Heo, J-O; Lim, J; Kamiya, Y; Yamaguchi, S; Sun, T-P, SCARECROW-LIKE 3 promotes gibberellin signaling by antagonizing DELLA in Arabidopsis, PNAS, vol. 108 (2011), pp. 2160-2165 .
  2. Murase, K; Hirano, Y; Sun, T-P; Hakoshima, T, Gibberellin-induced DELLA recognition by the gibberellin receptor GID1., Nature, vol. 456 no. 7221 (November, 2008), pp. 459-463 [doi]  [abs].
  3. Hu, J; Mitchum, MG; Barnaby, N; Ayele, BT; Ogawa, M; Nam, E; Lai, W-C; Hanada, A; Alonso, JM; Ecker, JR; Swain, SM; Yamaguchi, S; Kamiya, Y; Sun, T-P, Potential sites of bioactive gibberellin production during reproductive growth in Arabidopsis., The Plant cell, vol. 20 no. 2 (February, 2008), pp. 320-336 [doi]  [abs].
  4. Zentella; R; Zhang; Z-L; Park; M; Thomas, SG; G, S; Endo, A; A; Murase; K; Fleet; CM; Jikumaru; Y; Nambara; E; Kamiya; Sun; T-p, Global Analysis of DELLA Direct Targets in Early Gibberellin Signaling in Arabidopsis, Plant Cell, vol. 19 no. 10 (2007), pp. 3037-3057 [doi]  [abs].
  5. Griffiths, J; Murase, K; Rieu, I; Zentella, R; Zhang, ZL; Powers, SJ; Gong, F; Phillips, AL; Hedden, P; Sun, TP; Thomas, SG, Genetic characterization and functional analysis of the GID1 gibberellin receptors in Arabidopsis., The Plant Cell, vol. 18 no. 12 (December, 2006), pp. 3399-3414 [doi]  [abs].
  6. Dill, A; Thomas, SG; Hu, J; Steber, CM; Sun, T-P, The Arabidopsis F-Box Protein SLEEPY1 Targets GA Signaling Repressors for GA-Induced Degradation, Plant Cell, vol. 16 no. 6 (2004), pp. 1392-1405 [doi]  [abs].
  7. Dill, A; Jung, HS; Sun, TP, The DELLA motif is essential for gibberellin-induced degradation of RGA., Proceedings of the National Academy of Sciences of the United States of America, vol. 98 no. 24 (November, 2001), pp. 14162-14167 [doi]  [abs].
  8. Silverstone, AL; Jung, HS; Dill, A; Kawaide, H; Kamiya, Y; Sun, TP, Repressing a repressor: gibberellin-induced rapid reduction of the RGA protein in Arabidopsis., The Plant cell, vol. 13 no. 7 (July, 2001), pp. 1555-1566 [doi]  [abs].
  9. Yamaguchi; S; Smith; W, M; Brown; S, RG; Kamiya; Y; Sun; T-p, Phytochrome regulation and differential expression of gibberellin 3b-hydroxylase genes in germinating Arabidopsis seeds, Plant Cell, vol. 10 no. 12 (1998), pp. 2115-2126 [9836749], [doi]  [abs].
  10. Sun, T-P, Gibberellin-GID1-DELLA: a pivotal regulatory module for plant growth and development., Plant physiology, vol. 154 no. 2 (October, 2010), pp. 567-570 [doi] .
  11. T. Sun, Gibberellin Metabolism, Perception and Signaling Pathways, in The Arabidopsis Book, vol. doi: 10.1199/tab.0103 (September, 2008), American Society of Plant Biologists .