Start Date: Jul 03, 2008
End Date: Jun 30, 2013
Function of cold-responsive genes, such as the CBF gene, that have been isolated from blueberry flower buds, will be tested for their role in determining cold tolerance in blueberry. Constructs designed to over express and/or knock out expression of certain genes will be introduced into appropriate southern and northern highbush cultivars by Agrobacterium-mediated transformation. Introduction of the gene(s) will be confirmed by GUS assays, PCR, Southern blotting, etc. Expression of genes will be monitored by quantitative RT-PCR. Freeze tolerance of transgenic plants will be determined first by a controlled laboratory freeze together with an electrolyte leakage assay using leaf tissue. Later, as plants mature, freeze tolerance of flower buds will be determined visually by combining the controlled freeze together with dissection of buds and looking for browning. In this way, it will be determined if the introduced gene(s) result in an increase or decrease in freeze tolerance as compared to control levels.