Dr STEPHEN THOMAS

BIOGRAPHY

Stephen’s main research interests are aimed at understanding how hormonal signals control plant growth and development. His work has been focused predominantly on the gibberellin (GA) signalling pathway. This work has included using Arabidopsis as a model system to understand the role of biosynthesis and signalling genes in controlling tissue-specific growth responses, including stem elongation and floral development. By understanding how phytohormones control wheat architecture and fertility, his work is aimed at improving the genetic yield potential of this crop. Dwarfing genes in rice and wheat were instrumental in producing the dramatic increases in yields that were achieved during the “Green Revolution”. In wheat, the important semi-dwarfing mutations are Rht-B1b and Rht-D1b, which encode stabilised DELLA growth repressors that inhibit stem elongation. A major focus of Stephen’s work is to target other genetic components within this pathway as potential sources of superior dwarfing genes in hexaploid wheat. Stephen is also investigating the potential for manipulating wheat architecture by altering other phytohormone pathways. There is evidence that the currently available wheat Rht-1 dwarfing genes enhance susceptibility to abiotic stresses. Through understanding the role of GAs and other phytohormones, his work aims to develop genetic or chemical-based strategies to alleviating these effects.