Changes in gene expression during strawberry fruit ripening and their regulation by auxin

Abstract

Changes in messenger RNA during the development of the strawberry (Fragaria ananassa Duch.), a non-climacteric fruit, were analysed by extracting total RNA and separating the in-vitro translated products by two-dimensional polyacrylamide gel electrophoresis. Alterations in numerous messenger RNAs accompanied fruit development between the immature green stage and the overripe stage, with prominent changes detected at or before the onset of ripening. A number of messenger RNAs undetectable in immature green fruit increased as the fruit matured and ripened. Others showed a marked decrease in advance of the ripening phase. A further group of messenger RNAs was prominent in immature and ripe fruit but absent just prior to the turning stage. Removing the achenes from a segment of the fruit accelerated anthocyanin accumulation in the de-achened portion and produced a pattern of translated polypeptides similar to normal ripe fruit. Application of the synthetic auxin 1-naphthaleneacetic acid to the de-achened receptacle produced a translation pattern similar to that in mature green fruit. These findings indicate that ripening in strawberry is associated with the expression of specific genes.