桃树子房发育初期蔗糖含量及其相关酶活性的变化

Changes of Sucrose Content and Activities of Relative Enzymes in Sucrose Metabolism in the Early Developing Ovaries of Peach

【目的】研究桃树子房发育初期(从现蕾到花萎)蔗糖含量比率及蔗糖代谢相关酶比活力的变化规律。【方法】以‘京玉’和‘久保’两个桃品种为试材,研究桃树子房发育初期子房、韧皮部、叶片与花瓣中蔗糖、淀粉含量及蔗糖代谢关键酶——酸性转化酶(AI)、中性转化酶(NI)、蔗糖磷酸合酶(SPS)和蔗糖合酶(SS)比活力的变化。【结果】两品种各部位中蔗糖积累规律较为相似,韧皮部蔗糖含量比率明显高于其它部位;总可溶性糖在韧皮部中的积累量除盛花期(第10D)低于花瓣中含量,其余时期均较其它部位高,但总体呈下降趋势。子房发育初期子房和叶片中淀粉含量不断升高,韧皮部中则呈下降趋势,花瓣中含量先降低后升高。AI、NI比活力变化对糖的积累作用不明显,SS合成方向、SPS比活力变化与蔗糖的积累量变化一致,SS分解方向比活力变化对两品种桃树糖的积累和转化作用较为突出。【结论】韧皮部是桃树子房发育初期碳水化合物主要的代谢"源",子房发育初期蔗糖代谢相关酶时空性表达受到某些相关因子的调控。

【Objective】This experiment was carried out to study the changes of sucrose content ratio and sucrose-metabolizing enzymes specific activities in the early developing ovaries of peach （from the period of bud to wilt）. 【Method】The content of sucrose, starch and the specific activities of sucrose-metabolizing enzymes, including acid invertase （AI）, neutral invertase （NI）, sucrose phosphate synthase （SPS） and sucrose synthase （SS） were analyzed in the early developing ovaries of Jingyu and Okubao peach. 【Result】The rule of sucrose accumulation took a similar change in different parts of two cultivars, and the sucrose percentage of total soluble sugars was obviously higher in phloem than in other parts. The content of soluble sugar showed a descendent trend in general, and the content in phloem was higher than that in other parts except for the individual value in petal on the day of full flowering （the 10th day）. At the same time the content of starch increased continuously in ovary and leaf in the early developing ovaries, and it reduced in phloem besides the content depressed first and then elevated in petal. The specific activity of AI and NI showed a infirm influence on the increase of sugar content, whereas sucrose accumulation was in accord with SS-synthese and SPS specific activity. The accumulation and components of sugar were affected evidently by SS-disassemble activity.【Conclusion】 Phloem is the fountainhead of carbohydrate-metabolism in the early developing ovaries of peach. The space-time character expression of sucrose-metabolizing enzymes are regulated by some related factors.