Regulation of fruit ascorbic acid concentrations during ripening in high and low vitamin C tomato cultivars.
Regulation of fruit ascorbic acid concentrations during ripening in high and low vitamin C tomato cultivars.
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DOI：
10.1186/1471-2229-12-239
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发表时间：
2012-12-17
影响因子：
5.3
通讯作者：
Davey MW
中科院分区：
文献类型：
--
作者：
Mellidou I;Keulemans J;Kanellis AK;Davey MW
为了深入了解番茄中果实抗坏血酸 (AsA) 库的调节，分别对“低 AsA”和“高 AsA”番茄品种“Ailsa Craig”和“Santorini”的果实进行了代谢物分析、非标记和放射性标记底物饲喂实验、酶活性测量和基因表达研究。两个品种在成熟过程中总 AsA（totAsA、AsA + 脱氢抗坏血酸）和 AsA 积累表现出不同的特征，但都在破粒期表现出特征浓度峰值。底物饲喂实验表明，L-半乳糖途径是番茄果实中主要的 AsA 生物合成途径，但来自替代途径的底物可以增加特定发育阶段的 AsA 库。此外，我们发现，年轻的果实比成熟的果实表现出更高的 AsA 生物合成能力，但这并不会导致更高的 AsA 浓度，因为 AsA 分解率提高（“Ailsa Craig”）或 AsA 回收率降低（“Santorini”），具体取决于品种。在成熟后期，两个品种果实totAsA-AsA浓度的差异可以通过AsA回收率的差异来解释。 AsA 代谢基因表达分析表明，只有 GDP-L-半乳糖磷酸化酶 (SlGGP1) 的一种直系同源物和两种单脱氢抗坏血酸还原酶 (SlMDHAR1 和 SlMDHAR3) 的表达与‘Ailsa Craig’果实成熟过程中果实 totAsA-AsA 浓度的变化相关，并且只有 SlGGP1 的表达与 与红色成熟的“圣托里尼”水果中发现的高 AsA 浓度有关。结果表明，‘Ailsa Craig’和‘Santorini’使用互补机制来维持果实 AsA 库。在低 AsA 品种（“Ailsa Craig”）中，AsA 生物合成的替代途径可能通过 L-半乳糖补充生物合成，而在高 AsA 品种（“Santorini”）中，AsA 回收活动的增强似乎是成熟后期 AsA 积累的原因。基因表达研究表明，SlGGP1 和 SlMDHAR 的两个直系同源物的表达与成熟过程中的 totAsA-AsA 浓度密切相关，并且是育种和选择标记开发的潜在良好候选者。
To gain insight into the regulation of fruit ascorbic acid (AsA) pool in tomatoes, a combination of metabolite analyses, non-labelled and radiolabelled substrate feeding experiments, enzyme activity measurements and gene expression studies were carried out in fruits of the ‘low-’ and ‘high-AsA’ tomato cultivars ‘Ailsa Craig’ and ‘Santorini’ respectively. The two cultivars exhibited different profiles of total AsA (totAsA, AsA + dehydroascorbate) and AsA accumulation during ripening, but both displayed a characteristic peak in concentrations at the breaker stage. Substrate feeding experiments demonstrated that the L-galactose pathway is the main AsA biosynthetic route in tomato fruits, but that substrates from alternative pathways can increase the AsA pool at specific developmental stages. In addition, we show that young fruits display a higher AsA biosynthetic capacity than mature ones, but this does not lead to higher AsA concentrations due to either enhanced rates of AsA breakdown (‘Ailsa Craig’) or decreased rates of AsA recycling (‘Santorini’), depending on the cultivar. In the later stages of ripening, differences in fruit totAsA-AsA concentrations of the two cultivars can be explained by differences in the rate of AsA recycling activities. Analysis of the expression of AsA metabolic genes showed that only the expression of one orthologue of GDP-L-galactose phosphorylase (SlGGP1), and of two monodehydroascorbate reductases (SlMDHAR1 and SlMDHAR3) correlated with the changes in fruit totAsA-AsA concentrations during fruit ripening in ‘Ailsa Craig’, and that only the expression of SlGGP1 was linked to the high AsA concentrations found in red ripe ‘Santorini’ fruits. Results indicate that ‘Ailsa Craig’ and ‘Santorini’ use complementary mechanisms to maintain the fruit AsA pool. In the low-AsA cultivar (‘Ailsa Craig’), alternative routes of AsA biosynthesis may supplement biosynthesis via L-galactose, while in the high-AsA cultivar (‘Santorini’), enhanced AsA recycling activities appear to be responsible for AsA accumulation in the later stages of ripening. Gene expression studies indicate that expression of SlGGP1 and two orthologues of SlMDHAR are closely correlated with totAsA-AsA concentrations during ripening and are potentially good candidates for marker development for breeding and selection.
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影响因子：
3.5
作者：
ARRIGONI, O;DIPIERRO, S;BORRACCINO, G
通讯作者：
BORRACCINO, G
影响因子：
4.3
作者：
Arrigoni, O;Calabrese, G;Liso, R
通讯作者：
Liso, R
影响因子：
7.2
作者：
Gilbert, Louise;Alhagdow, Moftah;Baldet, Pierre
通讯作者：
Baldet, Pierre
影响因子：
4.1
作者：
Davey, Mark W.;Auwerkerken, Annemarie;Keulemans, Johan
通讯作者：
Keulemans, Johan
影响因子：
4.3
作者：
EDWARDS, EA;RAWSTHORNE, S;MULLINEAUX, PM
通讯作者：
MULLINEAUX, PM