Exogenous trehalose improves the survival of date palm suckers by enhancing thioredoxin-antioxidant systems activity

Abstract

Trehalose, a disaccharide, regulates osmotic pressure, stabilizes proteins, and plays in the signaling of carbon allocation in response to abiotic stresses. This study was evaluated the effects of 100 mM pre-separation (7 days before de-suckering) and post-separation (immediately after planting) spraying of trehalose on the survival of ‘Mazafati’ date palm suckers from a molecular perspective. Our results showed a 42% increase in the survival rate of the suckers sprayed with trehalose. By triggering trehalose-phosphate synthase (TPS) gene expression, promoting endogenous trehalose accumulation in suckers sprayed with trehalose could be responsible for sufficient intracellular NADP+ supplying arising from enhancing NAD kinase (NADK) enzyme activity. In addition, higher 2-cysteine peroxiredoxin (2-Cys-Prx) gene expression and enzyme activity could be ascribed to triggering NADPH-dependent thioredoxin reductase C (NTRC) gene expression and enzyme activity, promoting thioredoxin (Trx) enzyme activity concomitant with triggering nucleoside diphosphate kinase (NDPK) gene expression. Lower H2O2 accumulation in suckers sprayed with trehalose could be responsible for protecting membrane integrity as shown by lower electrolyte leakage and malondialdehyde (MDA) accumulation. In addition to promoting antioxidant system activity, higher phenols and anthocyanins accumulation in date palm suckers sprayed with trehalose could be ascribed to enhancing shikimate-phenylpropanoid pathways activity by Trx system activity. The results indicate that the Trx system could be employed by endogenous trehalose accumulation for improving photosynthesis efficiency and enhancing the survival rate of the suckers.