Enhancement of Osmotic Stress Tolerance in Rice 98

Enhancement of Osmotic (Salinity) Stress Tolerance in Rice - 98
Project Leader and Principal UC Investigators Jan Dvorak, Professor, Department of Agronomy and Range Science, University of California, Davis David Mackill, Research Geneticist, USDA-ARS, Department of Agronomy and Range Science, University of California, Davis Sham Goyal, Specialist, Department of Agronomy and Range Science, University of California, Davis Ming-Jun Gao, Visiting Scientist, Department of Agronomy and Range Science, University of California, Davis Patrick J. Gulick, Professor, Concordia University, Montreal, Canada Timothy J. Close, Associate Professor, Department of Plant Science, University of California, Riverside	Concern over increasing salinity in parts of the Sacramento Valley prompted this study into the basic biology of salt-stressed rice. The aim is to develop an understanding of the cellular mechanisms that control salinity tolerance in California rice and to target genes for the transgenic development of salt-tolerant varieties. High levels of dehydrin proteins have been observed in salt-stressed rice and other grasses. A detailed analysis of the genetic structure of the dehydrin protein family revealed that the production of dehydrins induced by salinity is controlled by a large number of genes. It is unlikely, therefore, that salinity tolerance could be dramatically improved by the incorporation of a single salinity tolerance gene from a highly salt-tolerant source like the wheatgrass Lophopyrum. Salinity tolerance in rice and other cereals is also highly correlated with the exclusion of sodium and the maintenance of potassium in developing tissues and rapidly growing leaves. Researchers are searching for genes that control this physiological trait (K/Na selectivity) in rice and other grasses such as a salt-tolerant goatgrass. The ultimate goal is to isolate these genes and use them in the development of salinity tolerant transgenic rice. In a parallel approach geared toward moderate enhancement of salinity tolerance, the rice germplasm collection is being screened to identify K/Na selectivity superior to existing California varieties. If successful, this germplasm would be used in marker-assisted breeding of improved salinity tolerance in California rice.

Enhancement of Osmotic
(Salinity) Stress Tolerance
in Rice - 98

Project Leader and Principal UC Investigators

Jan Dvorak, Professor, Department of Agronomy and Range Science, University of California, Davis

David Mackill, Research Geneticist, USDA-ARS, Department of Agronomy and Range Science, University of California, Davis

Sham Goyal, Specialist, Department of Agronomy and Range Science, University of California, Davis

Ming-Jun Gao, Visiting Scientist, Department of Agronomy and Range Science, University of California, Davis

Patrick J. Gulick, Professor, Concordia University, Montreal, Canada

Timothy J. Close, Associate Professor, Department of Plant Science, University of California, Riverside

Concern over increasing salinity in parts of the Sacramento Valley prompted this study into the basic biology of salt-stressed rice. The aim is to develop an understanding of the cellular mechanisms that control salinity tolerance in California rice and to target genes for the transgenic development of salt-tolerant varieties.

High levels of dehydrin proteins have been observed in salt-stressed rice and other grasses. A detailed analysis of the genetic structure of the dehydrin protein family revealed that the production of dehydrins induced by salinity is controlled by a large number of genes. It is unlikely, therefore, that salinity tolerance could be dramatically improved by the incorporation of a single salinity tolerance gene from a highly salt-tolerant source like the wheatgrass Lophopyrum.

Osmotic.jpg (224041 bytes) Salinity tolerance in rice and other cereals is also highly correlated with the exclusion of sodium and the maintenance of potassium in developing tissues and rapidly growing leaves. Researchers are searching for genes that control this physiological trait (K/Na selectivity) in rice and other grasses such as a salt-tolerant goatgrass. The ultimate goal is to isolate these genes and use them in the development of salinity tolerant transgenic rice.

In a parallel approach geared toward moderate enhancement of salinity tolerance, the rice germplasm collection is being screened to identify K/Na selectivity superior to existing California varieties. If successful, this germplasm would be used in marker-assisted breeding of improved salinity tolerance in California rice.