ABSTRACT

Plant hormones have been extensively studied for their roles in the regulation of various aspects of plant development. However, in the last decade important new insights have been made into their action during development and ripening, in both dry and fleshy fruits. Emerging evidence suggests that relative functions of plant hormones are not restricted to a particular stage, and a complex network of more than one plant hormone is involved in controlling various aspects of fruit development. Though some areas are extensively covered, considerable gaps in our knowledge and understanding still exist in the control of hormonal networks and crosstalk between different hormones during fruit expansion, maturation, and various other aspects of ripening. Here, we evaluate the new knowledge on their relative roles during tomato fruit development with a view to understand their mechanism of action in fleshy fruits. For a better understanding, pertinent evidences available on hormonal crosstalk during fruit development in other species are also discussed. We envisage that such detailed knowledge will help design new strategies for effective manipulation of fruit ripening.

INTRODUCTION

In angiosperms, fruiting bodies have evolved to facilitate seed maturation and their subsequent dispersal. A diverse range of fruit types from dry to fleshy forms exists across plant species. Evolutionary studies predict that species that produce dry fruit are the ancestors of species that produce fleshy fruit, and this is the reason for the prevalence of common developmental mechanisms between the two types (Knapp, 2002). In Arabidopsis, the model plant with dry fruits, a high-level regulatory network of transcription factors controlling fruit development has been identified. Similarly, studies on tomato, a model for fleshy fruits, have provided new insights into the networks responsible for the control of ripening (Tomato Genome Consortium, 2012). Together, strong similarities between dry and fleshy as well as within different fleshy fruits in the molecular circuits governing development and maturation indicate that regulatory networks are conserved across a wide spectrum of angiosperm fruit (Seymour et al., 2013).

You can read the entire publication here