Ascorbate biosynthesis and its involvement in stress tolerance and plant development in rice (Oryza sativa L.)
Ascorbate biosynthesis and its involvement in stress tolerance and plant development in rice (Oryza sativa L.)
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DOI：
10.1007/s11103-015-0341-y
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发表时间：
2015-08-01
影响因子：
5.1
通讯作者：
Frei, Michael
中科院分区：
文献类型：
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作者：
Hoeller, Stefanie;Ueda, Yoshiaki;Frei, Michael
以水稻抗坏血酸（AsA）生物合成基因敲除突变体及其野生型为材料，研究了抗坏血酸（阿萨）生物合成及其对植物生长发育和抗逆的影响。GDP-D-甘露糖差向异构酶（OsGME）的两种异构体的KO使叶片阿萨水平降低20- 30%，GDP-L-半乳糖磷酸化酶（OsGGP）的KO使叶片AsA水平降低80%，而肌醇加氧酶（OsMIOX）的KO不影响叶片阿萨水平。臭氧胁迫和缺锌条件下，阿萨浓度与叶片组织脂质过氧化呈负相关，但不影响对铁毒的敏感性。阿萨缺乏降低了光合效率，表现为Rubisco最大羧化速率（V-max）、最大电子传递速率（J（max））和叶绿素荧光参数FPSII。突变体显示出比它们的野生型更低的生物量生产，特别是当缺乏OsGGP时（约80%减少）。除OsGGP KO突变体外，其他所有植株叶片阿萨浓度在生长过程中均出现明显的峰值，这与OsGGP表达上调一致，表明OsGGP在不同生长阶段对叶片阿萨水平的调节起着关键作用。综上所述，我们的数据表明阿萨在水稻的抗逆性和发育中起着多重作用。
Ascorbic acid (AsA) biosynthesis and its implications for stress tolerance and plant development were investigated in a set of rice knock-out (KO) mutants for AsA biosynthetic genes and their wild-types. KO of two isoforms of GDP-D-mannose epimerase (OsGME) reduced the foliar AsA level by 20-30 %, and KO of GDP-L-galactose phosphorylase (OsGGP) by 80 %, while KO of myoinositol oxygenase (OsMIOX) did not affect foliar AsA levels. AsA concentration was negatively correlated with lipid peroxidation in foliar tissue under ozone stress and zinc deficiency, but did not affect the sensitivity to iron toxicity. Lack of AsA reduced the photosynthetic efficiency as represented by the maximum carboxylation rate of Rubisco (V-max), the maximum electron transport rate (J(max)) and the chlorophyll fluorescence parameter FPSII. Mutants showed lower biomass production than their wild-types, especially when OsGGP was lacking (around 80 % reductions). All plants except for KO mutants of OsGGP showed distinct peaks in foliar AsA concentrations during the growth, which were consistent with up-regulation of OsGGP, suggesting that OsGGP plays a pivotal role in regulating foliar AsA levels during different growth stages. In conclusion, our data demonstrate multiple roles of AsA in stress tolerance and development of rice.