Hormonal changes during non-climacteric ripening in strawberry

Abstract

In contrast to climacteric fruits, where ethylene is known to be pivotal, the regulation of ripening in non-climacteric fruits is not well understood. In the non-climacteric strawberry (Fragaria anannassa), auxin and abscisic acid (ABA) are thought to be important, but the roles of other hormones suggested to be involved in fruit development and ripening are not clear. Here changes in the levels of indole-3-acetic acid (IAA), ABA, GA1, and castasterone from anthesis to fully ripened fruit are reported. The levels of IAA and GA1 rise early in fruit development before dropping to low levels prior to colour accumulation. Castasterone levels are highest at anthesis and drop to very low levels well before ripening commences, suggesting that brassinosteroids do not play an important role in ripening in strawberry. ABA levels are low at anthesis and gradually rise through development and ripening. The synthetic auxin, 1-naphthaleneacetic acid (NAA), can delay ripening, but the application of GA3, the gibberellin biosythesis inhibitor paclobutrazol, and ABA had no significant effect. IAA and ABA levels are higher in the developing achenes than in the receptacle tissue and may be important for receptacle enlargement and ripening, and seed maturation, respectively. Contrary to a recent report, the biologically active GA4 was not detected. The pattern of changes in the levels of the hormones are different from those reported in another well studied non-climateric fruit, grape, suggesting that a single consistent pattern of hormone changes does not occur in this group of fruit during ripening.

Effect of Pre-harvest Application of Hexanal and Growth Regulators in Enhancing Shelf Life and Regulation of Membrane Associated Genes in Strawberry

“…There is some evidence implicating auxin, gibberellins (GA) and abscisic acid (ABA), but much of this evidence relies on hormones quantification during fruit development or exogenous hormone application studies (Manning 1993;Fait et al 2008;Symons et al 2012).…”

Effect of ethylene treatment on phytochemical and ethylene-related gene expression during ripening in strawberry fruit Fragaria x ananassa cv. Camino Real

“…Strawberries are one of the most economically important fruits (Quesada et al, 2009) and their consumption has rapidly increased (Ji et al, 2012) mainly due to improvements in their flavor and nutritional quality (Symons et al, 2012). The strawberry is a non-climacteric fruit, which is a member of the Rosaceae family.…”

“…Ethylene is primarily related to the ripening of climacteric fruits (Symons et al, 2012), but its importance in non-climacteric fruit should also be considered. Non-climacteric fruits are able to synthesize ethylene; therefore, the involvement of this hormone in physiological and molecular events has been reported during strawberry development and ripening (Trainotti et al, 2005;Villarreal et al, 2010;Merchante et al, 2013;Sun et al, 2013).…”

Transcript Profiles of Auxin Efflux Carrier and IAA-Amido Synthetase Genes Suggest the Role of Auxin on Apple (<i>Malus</i> × <i>domestica</i>) Fruit Maturation Patterns

“…Specific distribution of auxin in fruit tissues by the function of auxin transporters has been shown to regulate fruit development and ripening [34]- [39]. However, crosstalk among hormones rather than individual action is most likely to be the common theme regulating most biological processes including fruit ripening [31] [32] [40]- [42]. In particular, auxin-ethylene interaction in plants has been well-documented [43]- [45], though very little is known in maturing apple fruit.…”