Author
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Bausher, Michael |
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Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only Publication Acceptance Date: 5/20/2005 Publication Date: 7/1/2005 Citation: Bausher, M.G. 2005. Isolation and characterization of the sucrose synthase promoter from citrus sinensis l. osbeck cv. valencia in transgenic tobacco. Proceedings of 2005 Annual Meeting of the American Society of Plant Biologists Annual Meeting.2005.p.308:1089 Interpretive Summary: Plants need specialized systems to ward off predators such as insects which feed on plant sap. When a plant needs products to protect themselves from insects they make chemical which make the plant an unsutable feeding site. Gene promoters can be used as the trigger to make these products and this work outlnes the discovery of triggering system which is specific tp the vascular areas targeted by insects that feed on the sap of plants such as aphids, having promoters specific to certain parts of the plant make it possible to ward off insects by creating anti-feeding products which cause the insect to go to a different host. Technical Abstract: Pathogen-induced vascular diseases in addition to herbivory by insects that feed on plant sap cause significant losses to production, not just in annual crop species but woody perennials as well. Combating these biotic stresses with transgenic plants will require the use of promoter elements specific to the tissues affected in order to reduce the fitness costs and maximize crop yield. Here we describe the isolation of the putative promoter region for the sucrose synthase gene in citrus which we obtained by walking upstream using primers designed from the full-length cDNA derived from a Citrus phloem cDNA library. Three amplicons of different lengths relative to the transcription start site (-1563, -755, -503) were generated and fused to the GUSA gene in the binary vector pTRM-T to create the experimental constructs pTRM-503, pRTM-755 and pTRM-1563. Histochemical GUS analysis revealed that expression in all three constructs was limited to the vascular tissue of leaves and stems but not roots and that the level of expression appeared to be construct-specific. The construct pRTm-503 showed weak expression, while both the pRTM-1563 and pRTM-755 constructs showed dramatically increased GUS expression relative to controls. Our results show in subsequent experiments that this promoter is highly tissue-specific and inducible by several abiotic stresses and therefore has the potential to be used to control transgene expression in citrus vascular tissue. |
