Eight cDNA encoding putative aquaporins in Vitis hybrid Richter-110 and their differential expression

The nucleotide sequences of eight cDNAs encoding putative aquaporins obtained from a leaf Vitis hybrid Richter-110 cDNA library are reported. They encode proteins ranging from 249 to 287 amino acids with characteristic sequences that clearly include them within the MIP family. According to available database sequence homologies, they can be classified into four groups belonging to two subfamilies: PIP (PIP1 and PIP2) and TIP (gamma-TIP and delta-TIP). In order to elucidate the expression patterns of these putative aquaporins in the plant, specific probes were developed and tissue specific differential expression was tested by reverse Northern and compared with two reference genes (malic enzyme and glutamate dehydrogenase). Clearly, most of the putative aquaporins had higher expression in roots, whereas expression in shoot and leaves was generally weaker than the reference genes.