Compatible solutes improve regrowth, ameliorate enzymatic antioxidant systems, and reduce lipid peroxidation of cryopreserved Hancornia speciosa Gomes lateral buds

Abstract

Hancornia speciosa is a native fruit species from Brazil with important economic applications. However, the use of this species has been challenged by difficulties in its storage. Cryopreservation is a safe and efficient tool for long-term storage. Nevertheless, cryopreservation may promote reactive oxygen species (ROS) formation with subsequent lipid peroxidation, which causes membrane damage. The use of in vitro antioxidant compounds could help eliminate ROS and consequently improve explant survival. In the current study, the lateral buds of H. speciosa were precultivated in proline or glycine betaine (GB)-containing solutions, and the effect of these compounds on the enzymatic activity of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) and on lipid peroxidation was measured after sample warming. The present findings indicated that oxidative stress induced by cryopreservation was significantly reduced by the precultivation of lateral buds with proline and GB. SOD activity increased, and subsequently, hydrogen peroxide (H2O2) production increased followed by the immediate activation of CAT and APX. The enzyme activity increased for 7 following rewarming, indicating that precultivation with 0.1 M proline was fundamental to achieving high levels of shoot regeneration from H. speciosa lateral buds.