MERCURY AFFECTS AQUAPORINS ACTIVITY AND GERMINATION OF THE EMBRYONIC AXIS OF Schizolobium parahyba (VELL.) BLAKE (FABACEAE)

Abstract

ABSTRACT Germination is a physiological process that begins with hydration. Specific channels known as aquaporins are responsible for water uptake through biological cell membranes. The mercuric chloride (HgCl2) reversibly inhibits water transport during germination through the aquaporins and can changes deoxyribonucleic acid (DNA) integrity, which can result in aquaporins deficiency. The aim of this study was to evaluate the effect of HgCl2 and dithiothreitol (DTT) on aquaporins activity and on the integrity/degradation of DNA in embryonic axes of Schizolobium parahyba (Vell.) Blake during the germination process. Isolated axes were exposed to different concentrations of HgCl2 or DTT; and aquaporins activity, embryo hydration, and DNA integrity were evaluated during embryonic axes imbibition. Growth and changes in axis fresh weight were quantified. We found that the heavy metal affects seed hydration by inhibition of aquaporins activity and does not cause changes in DNA integrity.