Isolation and characterization of mRNAs differentially expressed during ripening of wild strawberry (Fragaria vesca L.) fruits.

Abstract

Wild strawberry (Fragaria vesca L.) is an attractive model system for studying ripening in non-climacteric fruit, because of its small diploid genome, its short reproductive cycle, and its capacity for transformation. We have isolated eight ripening-induced cDNAs from this species after differential screening of a cDNA library. The predicted polypeptides of seven of the clones exhibit similarity to database protein sequences, including acyl carrier protein, caffeoyl-CoA 3-O-methyltransferase, sesquiterpene cyclase, major latex protein, cystathionine gamma-synthase, dehydrin and an auxin-induced gene. A ninth cDNA clone that was constitutively expressed is predicted to encode a metallothionein-like protein. None of these proteins appear to be directly related to events generally associated with ripening such as cell wall metabolism or the accumulation of sugars and pigments, rather, their putative functions are indicative of the wide range of processes upregulated during fruit ripening.