Ultraviolet-B radiation exposure lowers the antioxidant capacity in the Arabidopsis thaliana pdx1.3-1 mutant and leads to glucosinolate biosynthesis alteration in both wild type and mutant
Ultraviolet-B radiation exposure lowers the antioxidant capacity in the Arabidopsis thaliana pdx1.3-1 mutant and leads to glucosinolate biosynthesis alteration in both wild type and mutant
复制标题
UV-B辐射降低拟南芥pdx 1.3 -1突变体的抗氧化能力并导致野生型和突变体中硫代葡萄糖苷生物合成的改变
DOI：
10.1039/c9pp00342h
复制
发表时间：
2020-02-01
影响因子：
3.1
通讯作者：
Strid, Ake
中科院分区：
文献类型：
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作者：
Neugart, Susanne;Hideg, Eva;Strid, Ake
吡哆醇(维生素B-6)及其维生素被活的生物体用作酶辅助因子和抗氧化剂。我们利用拟南芥吡哆醇生物合成突变体pdx1.3-1研究了PLP合成酶主要多肽pdx1参与植物对两种不同性质的紫外线辐射的反应，一个主要含有UV-A(315-400 nm)，另一个同时含有UV-A(280-315 nm)和UV-B(280-315 nm)。测定了其抗氧化能力及黄酮类和硫代葡萄糖苷(GS)的含量。以光系统II反应中心的F-v/F-m作为逆境指标。在pdx1.3-1中，UV-A+B暴露导致最后一天(第15天)F-v/F-m显著下降5%，表明该时间点处于轻度应激状态。在UV-A+B处理1天和3天后，野生型Col-0的抗氧化能力显著提高(50-73%)，而在pdx1.3-1中，抗氧化能力在同一时间段显著下降44-52%，证明了完整的功能PDX1基因对活性氧物种解毒的重要性。在任何光照条件下，黄酮苷的含量都没有明显的变化。然而，GS图谱发生了显著的变化，无论是关于拟南芥的加入和对紫外线的暴露。类黄酮和GS组分的差异反映了GS生物合成途径中至少含有一种依赖于吡哆醇的酶，而没有这种酶用于类黄酮的生物合成。抗氧化能力与某些GS类化合物的含量有很强的相关性。我们的结果表明，维生素B-6维生素既具有抗氧化剂的功能，又具有辅助因子的功能，对于植物的生理适应性是重要的。
Pyridoxine (vitamin B-6) and its vitamers are used by living organisms both as enzymatic cofactors and as antioxidants. We used Arabidopsis pyridoxine biosynthesis mutant pdx1.3-1 to study the involvement of the PLP-synthase main polypeptide PDX1 in plant responses to ultraviolet radiation of two different qualities, one containing primarily UV-A (315-400 nm) and the other containing both UV-A and UV-B (280-315 nm). The antioxidant capacity and the flavonoid and glucosinolate (GS) profiles were examined. As an indicator of stress, F-v/F-m of photosystem II reaction centers was used. In pdx1.3-1, UV-A + B exposure led to a significant 5% decrease in F-v/F-m on the last day (day 15), indicating mild stress at this time point. The antioxidant capacity of Col-0 wildtype increased significantly (50-73%) after 1 and 3 days of UV-A + B. Instead, in pdx1.3-1, the antioxidant capacity significantly decreased by 44-52% over the same time period, proving the importance of a full complement of functional PDX1 genes for the detoxification of reactive oxygen species. There were no significant changes in the flavonoid glycoside profile under any light condition. However, the GS profile was significantly altered, both with respect to Arabidopsis accession and exposure to UV. The difference in flavonoid and GS profiles reflects that the GS biosynthesis pathway contains at least one pyridoxine-dependent enzyme, whereas no such enzyme is used in flavonoid biosynthesis. Also, there was strong correlation between the antioxidant capacity and the content of some GS compounds. Our results show that vitamin B-6 vitamers, functioning both as antioxidants and co-factors, are of importance for the physiological fitness of plants.