Our lab is taking a molecular-genetic approach to investigating the role of endogenous sugar levels in regulating plant gene expression and development. Sugars may be considered to be similar to hormones in that they are synthesized in one part of the plant and then transported to other parts of the plant where they affect gene expression, time of flowering, early seedling development and other plant processes. To learn more about the role of soluble sugar levels in regulating plant development, and to identify the signal transduction pathways between sugar and gene expression, we isolated mutants of Arabidopsis thaliana that are defective in their response to sugar. Currently, we are focusing our efforts on the sis3, sis8 and hac1 mutants that carry mutations in an ubiquitin e3 ligase, a protein kinase and a histone acetyl transferase, respectively. In addition to addressing basic scientific questions, a long-term goal of our research is to engineer more productive plants by altering the way that plants respond to sugar in order to manipulate source-sink interactions.

A second project in our lab is aimed at using genetic engineering to increase the levels of two anti-cancer agents, vincristine and vinblastine, in C. roseus (periwinkle).

A third project in our lab focuses on identifying soybean expression quantitative trait loci (eQTL) that are involved in controlling seed yield or composition.

Tanvir, R., Gibson, S.I., Wurtele, E.S., Li, L. (2023) Editorial: Carbon allocation, volume II. Front. Plant Sci. 14:1342494. Doi: 10.3389/fpls.2023.1342494 

Li, C.Y., Gibson, S.I. (2021) Repression of ZCT1, ZCT2 and ZCT3 affects expression of terpenoid indole alkaloid biosynthetic and regulatory genes. PeerJ 9:e11624.

Li, C.Y., Leopold**, A.L., Sander, G.W., Shanks, J.V., Zhao*, L., Gibson, S.I. (2015) CrBPF1 overexpression alters transcript levels of terpenoid indole alkaloid biosynthetic and regulatory genes. Front. Plant Sci. 6, 818 

Gibson, S. I. (2015) Promoting an active form of learning out-of-class via online “study questions” leads to higher than expected exam scores in General Biology. PeerJ 3:e1322 

Lin, R., Glazebrook, J., Katagiri, F., Orf, J.H., Gibson, S.I. (2015) Identification of differentially expressed genes between developing seeds of different soybean cultivars. Genom. Data 6, 92-98 

Huang, Y., Li, C.Y., Qi, Y., Park, S., Gibson, S.I. (2014) SIS8, a putative mitogen-activated protein kinase kinase kinase, regulates sugar resistant seedling development in Arabidopsis. Plant J. 77, 577-588 

Li, C.Y., Leopold, A.L., Sander, G.W., Shanks, J.V., Zhao, L., Gibson, S.I. (2013) The ORCA2 transcription factor plays a key role in regulation of the terpenoid indole alkaloid pathway. BMC Plant Biol. 13, 155 

Heisel, T.J., Li, C.Y., Grey, K.M., Gibson, S.I. (2013) Mutations in HISTONE ACETYLTRANSFERASE1 affect sugar response and gene expression in Arabidopsis. Front. Plant Sci. 4, 245. 

Huang, Y., Li, C.Y., Pattison, D.L., Gray, W., Park, S., and Gibson, S.I. (2010). SUGAR INSENSITIVE3, a RING E3 ligase, is a new player in plant sugar response. Plant Physiol. 152, 1889-1900.

Huang, Y., Li, C.Y., Biddle, K.D., and Gibson, S.I. (2008). Identification, cloning and characterization of sis7 and sis10 sugar-insensitive mutants of Arabidopsis. BMC Plant Biol. 8, 104.

Peebles, C.A.M., Gibson, S.I., Shanks, J.V., and San, K.-Y. (2007). Long-term maintenance of a transgenic Catharanthus roseus hairy root line. Biotechnol. Prog. 23, 1517-1518.

Peebles, C.A.M., Gibson, S.I., Shanks, J.V., and San, K.-Y. (2007). Characterization of an ethanol-inducible promoter system in Catharanthus roseus hairy roots. Biotechnol. Prog. 23, 1258-1260.

Hong, S.-B., Peebles, C.A.M., Shanks, J.V., San, K.-Y., and Gibson, S.I. (2006). Terpenoid indole alkaloid production by Catharanthus roseus hairy roots induced by Agrobacterium tumefaciens harboring rol ABC genes. Biotechnol. Bioeng. 93, 386-390.

Hong, S.-B., Peebles, C.A.M., Shanks, J.V., San, K.-Y., and Gibson, S.I. (2006). Expression of the Arabidopsis feedback-insensitive anthranilate synthase holoenzyme and tryptophan decarboxylase genes in Catharanthus roseus hairy roots. J. Biotechnol. 122, 28-38.

Peebles, C.A.M., Hong, S.-B., Gibson, S.I., Shanks, J.V., and San, K.-Y. (2006). Effects of terpenoid precursor feeding on Catharanthus roseus hairy roots over-expressing the alpha or the alpha and beta subunits of anthranilate synthase. Biotechnol Bioeng 93, 534-540.

Peebles, C.A.M., Hong, S.-B., Gibson, S.I., Shanks, J.V., and San, K.-Y. (2005). Transient effects of over-expressing anthranilate synthase alpha and beta subunits in Catharanthus roseus hairy roots. Biotech. Prog. 21, 1572-1576.

Gibson, S.I. (2005). Control of plant development and gene expression by sugar signaling. Curr. Opin. Plant Biol. 8 , 93-102.

Gibson, S.I. (2004). Sugar and phytohormone response pathways: navigating a signaling network. J. Exp. Bot. 55 , 253-264.

Hughes, E.H., Hong, S.B., Gibson, S.I. , Shanks, J.V. and San, K.Y. (2004). Expression of a feedback-resistant anthranilate synthase in Catharanthus roseus hairy roots provides evidence for tight regulation of terpenoid indole alkaloid levels. Biotechnol. Bioeng. 86 , 718-727.

Hughes, E.H., Hong, S.B., Gibson, S.I. , Shanks, J.V. and San, K.Y. (2004). Metabolic engineering of the indole pathway in Catharanthus roseus hairy roots and increased accumulation of tryptamine and serpentine. Metab. Eng. 6 , 268-276.

Hong, S.-B., Hughes, E.H., Shanks, J.V., San, K.-Y. and Gibson, S.I. (2003). Role of the non-mevalonate pathway in indole alkaloid production by Catharanthus roseus hairy roots. Biotechnol. Prog. 19 , 1105-1108.

To, J.P.C., Reiter, W.-D. and Gibson, S.I. (2003). Chloroplast biogenesis by Arabidopsis seedlings is impaired in the presence of exogenous glucose. Physiol. Plant. 118 , 456-463.

Finkelstein, R.R. and Gibson, S.I. (2002). ABA and sugar interactions regulating development: cross-talk or voices in a crowd? Curr. Opin. Plant Biol. 5 , 26-32.

Hughes, E.H., Hong, S.-B., San, K.-Y., Shanks, J.V. and Gibson, S.I. (2002). Characterization of an inducible promoter system in Catharanthus roseus hairy roots. Biotech. Prog. 18 , 1183-1186.

To, J.P.C., Reiter, W.-D. and Gibson, S.I. (2002). Mobilization of seed storage lipid by Arabidopsis seedlings is retarded in the presence of exogenous sugars. BMC Plant Biol. 2 , 4.

Gibson, S.I. , Laby, R.J. and Kim, D. (2001). The sugar-insensitive1 ( sis1 ) mutant of Arabidopsis is allelic to ctr1 . Biochem. Biophys. Res. Commun. 280 , 196-203.

Laby, R.J., Kim, D. and Gibson, S.I. (2001). The ram1 mutant of Arabidopsis exhibits severely decreased b -amylase activity. Plant Physiol. 127 , 1798-1807.

Chia, D.W., Yoder, T.J., Reiter, W.-D. and Gibson, S.I. (2000). Fumaric acid: an overlooked form of fixed carbon in Arabidopsis and other plant species. Planta211 , 743-751.

Gibson, S.I. (2000). Plant sugar-response pathways. Part of a complex regulatory web. Plant Physiol.124 , 1532-1539.

Laby, R.J., Kincaid, M.S., Kim, D. and Gibson, S.I. (2000). The Arabidopsis sugar-insensitive mutants sis4 and sis5 are defective in abscisic acid synthesis and response. Plant J.23 , 587-596.

Gibson, S.I. and Graham, I.A. (1999). Another player joins the complex field of sugar-regulated gene expression in plants. Proc. Natl. Acad. Sci. USA96 , 4746-4748.