Zeaxanthin epoxidase(ZEP)plays important roles in plant response to various environmental stresses by involving in ABA biosynthesis and xanthophyll cycle.A full length cDNA of PeZEP was isolated from moso bamboo(Phyllostachys edulis),which comprised a 138-bp 5 UTR,a 381-bp 3-UTR and a 2013-bp ORF encoding a putative protein of 670 amino acids.PeZEP was mainly expressed in leaf blades and leaf sheaths,and less in roots and culms.The transcript level of PeZEP in bamboo leaf was elevated with the increasing light intensity.PeZEP was significantly up-regulated in response to high light(1200 μmol·m-2·s-1)and reached to a higher level after 1 h treatment,and kept higher levels in the following hours.Besides,PeZEP was up-regulated under high temperature(42oC),and down-regulated under low temperature(4oC)and exogenous ABA treatment.The expression vector of PeZEP driven by CaMV 35S was constructed and transformed into Arabidopsis thaliana.The transgenic plants overexpressing PeZEP were generated and subjected to drought stress for morphological and physiological assays.Compared with Col-0,the transgenic plants demonstrated enhanced tolerance to drought stress,which appeared later wilting and higher survival rate.Moreover,higher value of Fv/Fm,higher activities of SOD,POD and CAT,and lower concentration of MDA were also observed in transgenic plants.Transcript levels of AtP5CS and AtRD29b related to drought stress were enhanced in transgenic plants.Collectively,these results indicated that PeZEP,as one of key enzymes involved in xanthophyll cycle and ABA biosynthesis,might play an important role in response to high light,higher and lower temperature,and drought stresses in bamboo.