Palm seeds are interesting models for studying seed reserve mobilization at the tissue level due to the abundance and complexity of reserves stored in their living endosperm cells and the development of a highly specialized haustorium. Dias et al. studied structural and physiological aspects of the initial phases of reserve mobilization in seeds of a neotropical palm, Butia capitata, and sought to characterize the interactions between the different developmental pathways of the haustorium and endosperm.
The authors performed morphological and histochemical evaluations of the haustorium, the endosperm adjacent to the embryo, and the peripheral endosperm of dry, imbibed, dormant seeds and seeds geminating for 2, 5 and 10 days.
The reserve mobilization occurs with the integration of two antagonistic developmental pathways: growth in haustorium and degradation in endosperm. After germination, the oxygen flow triggers a series of reactions involving reactive oxygen species (ROS) and hormones that induce the degradation of the endosperm cells and the translocation of the nutrients to the seedlings.