Investigation of temporal variations in endogenous gibberellin A₃ and A₄ in the leaves of birch (Betula platyphylla).

摘要

Bioactive gibberellins (GAs) affect nearly every process during plant growth and development. In the present study, endogenous GA₃ and GA₄ levels in young leaves of 2- to 4-year-old birch (Betula platyphylla) trees were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) during the phase from May to August. Concurrently, changes in the levels of GAs during each day were also determined in 4-year-old trees. Furthermore, the levels of GAs were analyzed in 15 four-year-old juvenile birch trees (yet to bolt/flower) and in 15 adult trees (just starting to bolt/flower) during different stages of growth. Our results displayed the basic various patterns of GA₃ and GA₄ levels of the transient variation over a single day and the periodic variation in the growth period from May to August in different ages of birch trees. The results suggested that GA₃ and GA₄ had a significant effect on promoting birch growth and flowering. This study also defined the optimal time period for the determination of a foliar spray of GA₃ and GA₄ to promote birch growth. Our study provides a theoretical foundation for the further investigation of the effects of GA₃ and GA₄ on the growth and development of birch trees.