Bausher, Michael .
A citrus sucrose synthase (CsSUS01) gene promoter contains elements directing tissue specific expression and response to abiotic stress.
Identification of inducible, tissue-specific promoters is crucial for the development of effective, directed transgene expression. We have cloned and characterized the putative promoter region of the sucrose synthase gene (CsSUS01) from Citrus sinensis (L.) Osbeck. The CsSUS01 promoter is able to direct expression of the reporter gene β-glucuronidase (GUS) in aerial vascular tissue, but not roots of transformed Nicotiana tabacum transformed plants. Promoter deletion analysis revealed that the region from -499 to +10 nt relative to the transcriptional start site is sufficient to drive significant reporter gene expression in a vascular tissue-specific manner. In addition, we subjected T1 plants harboring the deletion construct to several abiotic stresses. Drought-stress resulted in a significant increase in reporter gene expression, while heat-stress did not appear to alter reporter expression in any T1 plant. In contrast, cold-stress significantly reduced GUS expression in T1 plants harboring the construct pCPDSS-751 (-751 to +10) but did not affect expression in plants harboring the constructs pCPDSS-499, pCPDSS-84 or pCPDSS-1606 suggesting that the region between -751 and -499 contains elements that exert negative regulation in response to cold-stress. These results indicate that the CsSUS01 promoter from Citrus sinensis may provide efficient bioengineering tool to enhance vascular tissue expression of transgenes for pest and pathogen resistance.
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1 - USDA-ARS, Horticulture and Breeding Unit, 2001 South Rock Road, Fort Pierce , FL 34945
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM