LAUSR

Abstract By pot experiment method, this study investigated the role of plant hormone abscisic acid (ABA) in the foliar application of 10 μM lanthanum nitrate (La(NO3)3)-regulated the biosynthesis, regeneration and degradation of vitamin C (Vc) and the content of Vc in the fruit of strawberry at different periods of growth and development. The results showed that La(NO3)3 significantly increased the content of Vc by increasingthe activities of recycling enzymes glutathione reductase (GR), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and biosynthetic enzyme L-galactono-1,4-lactone dehydrogenase (GalLDH), and decreasing the activities of recycling enzyme APX and degrading enzyme ascorbic acid oxidase (AAO). Compared with La(NO3)3 alone, applications of different ABA biosynthesis inhibitor sodium tungstate (Tu) all markedly decreased the activities of GR, MDHAR and GalLDH, and increased the activities of DHAR and APX, which resulted in the reduction in the content of Vc. Meanwhile, La(NO3)3 induced the production of ABA and Tu reversed the effect of La(NO3)3 on ABA content. Our results suggested that La(NO3)3-induced ABA participated in the regulation of Vc content in the fruit of strawberry.