Plant & Animal Genome IX Conference Plant & Animal Genome IX Conference
Poster: Large Insert Libraries, Gene Isolation, Etc.
P02_06.html
M. truncatula acquires phosphate from the soil via two phosphate transporters, located in the epidermis and root hairs of the root. These transporters access inorganic phosphate from the soil solution but are unable to transport organic forms of phosphate such as phytate. In some soils, phytate comprises a significant percentage of the total phosphate. We aim to engineer M. truncatula plants that express a phytase gene under control of a root hair specific promoter to determine whether this increases the ability of the plants to grow in soils rich in phytate. Towards this goal, we are currently searching for a suitable promoter. It has previously been reported that the Pea RH-2 gene shows expression exclusively in the root hairs and epidermis of pea roots. Six clones have been isolated by screening phosphate-starved M. truncatula root cDNA library with an RH-2 probe obtained by PCR. Three out of six clones showed the highest homology to a pathogenesis-related protein, PR10-1 of Medicago truncatula and designated as MtPR10-3a, -4a and û5b. The remaining 3 clones are highly homologous to pea RH2 gene and designated as MtRH-1a, -11a and 12a. There are 96-98% similarity between MtPR10 genes and 98-99% similarity between MtRH genes at nucleotide level. Expression analyses are in progress.