Abstract: Alginate oligosaccharides (AOS) prepared from alginate was a potent plant elicitor.The wheat drought stress resistant ability enhanced by AOS was investigated in this study preliminarily.Hydroponic experiments were carried out and drought model was simulated by exposing the roots of wheat to 20% polyethylene glycol6000 (PEG-6000) solution and the wheat growth inhibition treated with PEG was observed.Compared with the PEG group,seedling and root length,fresh weight and RWC (%) were increased by 17.9%,26.2%,43.1% and 32.7% in the AOS group,respectively.Moreover,the activities of antioxidant enzymes were obviously enhanced but the content of malondialdehyde (MDA) was reduced by 37.9% in the samples treated by AOS.Additionally,the drought stress responsive genes involved in ABA signal pathway,such as late embryogenesis abundant protein 1 gene (LEA1),Sucrose non-fermenting 1-related protein kinase 2 gene (SnRK2) and 9-cis-epoxycarotenoid dioxygenase (NCED) were up-regulated by AOS.Our results suggested that AOS might regulate ABA-dependent signal pathway to enhance drought stress resistance of wheat during growth period.

Key words: alginate oligosaccharides, elicitor, drought resistance, stress responsive gene