WAR OF HORMONES OVER RESOURCE-ALLOCATION TO SEEDS - STRATEGIES AND COUNTERSTRATEGIES OF OFFSPRING AND MATERNAL PARENT

It is suggested that maternal parent and offspring have conflicting in terests over the extent of resource allocation to developing seeds. Wh ile maternal parent would be selected to allocate her resources optima lly among her offspring, the latter would be selected to demand more. In animals, offspring are known to demand additional resources either visibly (through intense vocal calls) or subtly through the production of hormones. In plants though parent offspring conflict over resource allocation has been invoked, the mechanism through which the parent a nd offspring interact in regulating resource allocation into developin g seeds is not yet clear. In this paper, we propose that the strategie s and counter-strategies of the offspring and mother during the develo pment of seeds might be manifested through the production of appropria te growth hormones. Accordingly, we predict (i) hormones that mobilize resources into seeds (e.g. auxins and gibberellic acid) shall be synt hesized exclusively by the offspring tissue and (ii) hormones that inh ibit resource flow in to seeds (e.g. abscisic acid) be produced exclus ively by the maternal tissue. We show that these predictions are suppo rted by existing literature on the temporal dynamics and source of pro duction of growth hormones during seed development. Finally, we sugges t that such analysis viewing the production of different hormones duri ng early seed development, as strategies and counter-strategies of mot her and offspring tissue, helps offer a meaningful interpretation of t he otherwise complex dynamics of hormone fluxes.