Qualea grandiflora Mart. (Vochysiaceae) seed reserves and aluminum: Usage and mobilization during germination and seedling development

Abstract

Qualea grandiflora Mart. is an aluminum (Al)‐accumulating Cerrado species with a metabolic dependency on Al. This study aimed to determine the presence and concentration of Al and other reserve components in Q. grandiflora seeds, as well as their respective distribution patterns, mobilization, and usage during germination and seedling growth. Thus, the concentration of Al and other minerals in seeds, seedlings, and soils was measured. Also, histochemical and energy‐dispersive X‐ray spectroscopy (EDS) analyses were performed to observe the distribution of Al, proteins, and lipids in Q. grandiflora seeds and seedlings. Additionally, the concentration of proteins and lipids was assessed as well. Hence, even in soils with low exchangeable Al3+, Q. grandiflora seeds accumulated about 6.43 g of Al/kg of dry matter (DM) together with considerable concentrations of N, P, K, Ca, and Mg. Exogenous Al had no effect on the germination properties of Q. grandiflora seeds. Furthermore, approximately 60% of the seed Al was translocated to seedling leaves. Proteins and lipids were the main organic reserves in Q. grandiflora seeds. The histochemical analysis revealed that the bulk of Al in seeds was in the cotyledons, which were also the location sites of proteins and lipids. Proteins and lipids were the primary source of energy and carbon for seedling growth. Therefore, fatty acids, proteins, and Al could play a central role during seed germination and seedling establishment, which could help to explain why this species is one of the most widespread plants in the Cerrado.