Antisense inhibition of tomato fruit sucrose synthase decreases fruit setting and the sucrose unloading capacity of young fruit
Antisense inhibition of tomato fruit sucrose synthase decreases fruit setting and the sucrose unloading capacity of young fruit
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DOI：
10.1105/tpc.11.12.2407
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发表时间：
1999-12-01
期刊：
影响因子：
11.6
通讯作者：
Nguyen-Quoc, B
中科院分区：
文献类型：
--
作者：
D'Aoust, MA;Yelle, S;Nguyen-Quoc, B
以花椰菜花叶病毒35S启动子控制下的果实特异性蔗糖合成酶（SuSy）反义RNA（TOMSSF）转基因番茄（Lycopersicon esculentum）为材料，研究了SuSy在番茄果实中的作用。反义RNA的组成型表达显著抑制了花和果皮组织中SuSy的活性。然而，抑制作用在胚乳中仅轻微，在胚、芽、叶柄和叶组织中检测不到。蔗糖磷酸合成酶的活性与SuSy的活性平行下降，但酸性转化酶活性并没有增加响应减少SuSy活性。对幼果碳水化合物含量的唯一影响是淀粉积累略有减少。在花后23 d，抑制SuSy活性并不降低果实的蔗糖输入能力，即使SuSy活性降低98%，也不降低由输入蔗糖合成淀粉的速率。然而，蔗糖卸载能力的I日龄的水果大幅下降，低SuSy活性的行。此外，从开花的第一周开始的SuSy反义果实具有较慢的生长速率。减少坐果，导致成熟时单株果实明显减少，观察到具有最少SuSy活性的植物。这些结果表明，SuSy参与了番茄幼果蔗糖输入能力的控制，这是座果和发育的决定因素。
The role of sucrose synthase (SuSy) in tomato fruit was studied in transgenic tomato (Lycopersicon esculentum) plants expressing an antisense fragment of fruit-specific SuSy RNA (TOMSSF) under the control of the cauliflower mosaic virus 35S promoter. Constitutive expression of the antisense RNA markedly inhibited SuSy activity in flowers and fruit pericarp tissues. However, inhibition was only slight in the endosperm and was undetectable in the embryo, shoot, petiole, and leaf tissues. The activity of sucrose phosphate synthase decreased in parallel with that of SuSy, but acid invertase activity did not increase in response to the reduced SuSy activity. The only effect on the carbohydrate content of young fruit was a slight reduction in starch accumulation. The in vitro sucrose import capacity of fruits was not reduced by SuSy inhibition at 23 days after anthesis, and the rate of starch synthesized from the imported sucrose was not lessened even when SuSy activity was decreased by 98%. However, the sucrose unloading capacity of I-day-old fruit was substantially decreased in lines with low SuSy activity. In addition, the SuSy antisense fruit from the first week of flowering had a slower growth rate. A reduced fruit set, leading to markedly less fruit per plant at maturity, was observed for the plants with the least SuSy activity. These results suggest that SuSy participates in the control of sucrose import capacity of young tomato fruit, which is a determinant for fruit set and development.