Differential Expression of Transcripts to Water Deficit Stress in Florida Hybrid Bunch Grape

Abstract

Water deficit stress responses in grape leaves were investigated at the molecular level by contrasting transcript fluctuations during water stress. The overall goal of this study was to identify and isolate transcripts expressed differentially in response to water stress, sequence and characterize the water stress induced genes. Stem cuttings from the stocks were planted in 5-gal pots and maintained for 2 years under greenhouse conditions. Water deficit stress was induced by withholding irrigation for 20 d on half of the plants whereas the other half remained irrigated. All were monitored by measuring soil moisture content at 5-, 10-, 15-, and 20-d intervals during plant growth. RNA from control and stressed leaf samples were used to identify differentially expressed transcripts to water stress employing the differential display RT PCR (DDRT-PCR). Expression of cDNA transcripts was greatly affected during the 10- and 15-d stress period. Overexpression of 14 transcripts and eight newly induced transcripts were reported over prolonged stress. Newly synthesized transcripts include ABF3, isoprene synthase, and water stress inducible protein.