Research programme in plant biotechnology

Programme leader: Dr. Teemu H. Teeri
tel. 358-0-434 6032
E-mail: teeri@operoni.helsinki.fi

One research group is approaching the flowering process of plants at the level of the molecular differentiation of floral organs. The researchers have isolated from Gerbera hybrida (Compositae) genes for both organ determination (transcription factors) and inflorescence specific metabolism (enzymes for anthocyanin synthesis), and the major objective is to reveal the components of the regulatory chain between these classes of genes.

Aspartic proteinases make up a widely distributed class of enzymes in animals, plants, microbes, and viruses. One other research group have purified the aspartic proteinase from barley grains, studied its enzymatic properties, and determined its primary structure. The research group's prospects are to elucidate the physiological role of aspartic proteinase in barley and to clarify the structural and biological mechanisms involved in the intracellular processing and targeting of plant proteins.

The researchers have isolated and are studying the so far only transposon described for barley, the retrotransposon BARE-1. This transposon is a major part of the barley genome (upwards of 6%). The research group wishes to understand why and how this element has spread in Hordeum, and what its effects are on the genome and plant. Retrotransposons and retroviruses belong to the large group of retroelements which replicate and transpose via reverse transcriptase.

Modern breeding can take use of gene transfer techniques. The goals are to transfer into barley genes that increase the value of the crop as a raw material for brewing or starch industry. These genes include a fungal gene for beta-glucanase and genes for enzymes that modify startch as it is synthesized in barley. The researchers have also studied starch synthesis and purified the soluble starch synthase of barley to an active fraction of four polypeptides. The aim is to isolate the gene(s) coding for the enzyme.

Potato is one of the most important agricultural crops both worldwide and in Finland. Potato viruses affect the viability of potato plants and reduce the yield. One reserach group has obtained transgenic plants expressing the coat protein of potato virus Y and potato leaf roll virus, and analyzed the virus resistance of these plants. The researchers have also constructed transgenic plants expressing the murine 2'-5'A synthetase gene and found that these plants show protection against several viruses. The programme is currently focused on following projects:

Molecular genetics of floral organ differentiation and pathways of secondary metabolism in gerbera