|Samac, Deborah - Debby|
Submitted to: Plant Nutrition Colloquium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/27/2005
Publication Date: 9/15/2005
Citation: Liu, J., Yamagishi, M., Uhde-Stone, C., Bucciarelli, B., Samac, D.A., Allan, D., Vance, C.P. 2005. Shoot signals and molecular regulation of P-deficiency induced genes in cluster roots of white lupin. In: Li, C.J., Zhang, F.S., Doberman, A., editors. Plant Nutrition for Food Security, Human Health and Environmental Protection. Proceedings of the 15th Plant Nutrition Colloquium, September 14-19, 2005, Beijing, The People's Republic of China. Beijing: Tsinghua University Press. p. 94-96.
Technical Abstract: White lupin has unique developmental and biochemical adaptations to acquire phosphorus (P) under P-deficient conditions including: cluster root formation and enhanced expression of many genes involved in cluster root development and metabolism; exudation of enzymes and organic acids from roots; increased root hair formation; and modified carbon metabolism. Using a genomics approach we have identified some 50 genes that are up-regulated in cluster roots under P-deficiency. Some of these clones isolated from a white lupin genomic library were further characterized. Analysis of the genomic structure and promoter sequences of several P-deficiency induced genes indicated that these promoters shared conserved cis-acting elements. Most recently we have discovered that sugars and photosynthate are critical effectors for enhanced expression of P-deficiency induced genes in cluster roots. P-deficiency induced genes and genes involved in sugar metabolism and/or sensing seem to be co-regulated by P status and also by light/dark conditions. Using RNA interference (RNAi), current experiments are aimed at defining the functional importance of P-deficiency induced genes.