Chengappa S, Guilleroux M, Phillips W, Shields R
Unilever Research, Sharnbrook, Beds, UK.
Plant Mol Biol. 1999 May;40(2):213-21. doi: 10.1023/a:1006136524725.
Sucrose is the photoassimilate transported from the leaves to the fruit of tomato yet the fruit accumulates predominantly glucose and fructose. Hydrolysis of sucrose entering the fruit can be accomplished by invertase or sucrose synthase. Early in tomato fruit development there is a transient increase in sucrose synthase activity and starch which is correlated with fruit growth and sink strength suggesting a regulatory role for sucrose synthase in sugar import. Using an antisense sucrose synthase cDNA under the control of a fruit-specific promoter we show that sucrose synthase activity can be reduced by up to 99% in young fruit without affecting starch or sugar accumulation. This result calls into question the importance of sucrose synthase in regulating sink strength in tomato fruit.
蔗糖是从番茄叶片运输到果实的光合产物，但果实中主要积累的是葡萄糖和果糖。进入果实的蔗糖水解可由转化酶或蔗糖合酶完成。在番茄果实发育早期，蔗糖合酶活性和淀粉会短暂增加，这与果实生长和库强相关，表明蔗糖合酶在糖分输入中起调节作用。利用果实特异性启动子控制下的反义蔗糖合酶cDNA，我们发现幼果中的蔗糖合酶活性可降低多达99%，而不影响淀粉或糖分积累。这一结果让人质疑蔗糖合酶在调节番茄果实库强中的重要性。
