|M.A. Dou, Y.L. Yao, L.Q. Du, G.M. Sun, X.M. Zhang, J.G. Li
|pineapple (Ananas comosus), various sections, sucrose, sucrose phosphate synthase, sucrose synthase
Sugar accumulation of ‘Comte de Paris’ pineapple fruits was measured from 20 days after anthesis (DAA) to maturity at 80 DAA. The sugar content was highest in the basal section of ripe fruit, followed by the medial section, apical section and fruit core.
Changes in activity of acid and neutral invertases (AI and NI respectively) and sucrose phosphate synthase (SPS) corresponded to changes in sugar concentration gradients within various sections during fruit maturation.
The higher activity of invertase in the basal section of the fruit likely was associated with rapid cleavage of sucrose.
High invertase activity would also help to form a sucrose gradient between the leaves and the fruit, which facilitated sucrose transport to the fruit.
Higher SPS activity in the apical section could promote the synthesis of sucrose, which indicated that the difference between activity of invertase and SPS resulted in the difference of sugar accumulation among the various sections.
Our results indicated that the SPS and invertase activity was a gradient distribution among the sections at the mature stage, which was similar with the sugar concentration, which showed the activities of SS and SPS had a great impact on the sugar accumulation in the medial and the basal sections of fruit during the period of 70 days after anthesis (DAA). Rapid sucrose accumulation of different sections was related with the increase of SPS activity and the reduction of NI activity from 70 to 80 d.
The activity of SS regulated the sucrose accumulation in the fruit apical and core section in the period of 70 DAA, However, the activities of AI, NI and SPS regulated the sucrose accumulation of the fruit core after 70 DAA, whereas the activities of NI and SPS regulated the sucrose accumulation in the apical, medial and basal sections of the fruit.
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