Antioxidant responses to drought in sunflower and sorghum seedlings.
Antioxidant responses to drought in sunflower and sorghum seedlings.
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DOI：
10.1111/j.1469-8137.1996.tb01856.x
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发表时间：
1996-03
期刊：
影响因子：
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通讯作者：
Jingxian Zhang;M. Kirkham
中科院分区：
文献类型：
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作者：
Jingxian Zhang;M. Kirkham
为了确定C3和C4植物对干旱的抗氧化反应是否不同，我们在生长室内分别在湿润和干燥的条件下种植双色高粱（C4）和向日葵（C3）。测定叶片酶促抗氧化剂（抗坏血酸过氧化物酶、过氧化氢酶、愈创木酚过氧化物酶、脱氢抗坏血酸还原酶、单脱氢抗坏血酸还原酶、谷胱甘肽还原酶和超氧化物歧化酶）、非酶促抗氧化剂（抗坏血酸、谷胱甘肽和类胡萝卜素）和胁迫参数（Chl和丙二醛[MDA]）的水平。在水分和干旱条件下，高粱Chl含量和叶片相对含水量（RWC）均高于向日葵；但向日葵的丙二醛含量高于高粱。在浇水条件下，高粱的内在抗氧化剂水平并不总是高于或低于向日葵。在干旱胁迫下，抗氧化剂、Chl和MDA的含量随作物、干旱持续时间和抗氧化剂种类的不同而增加、减少或保持不变。干旱的持续时间被任意地划分为三个阶段。在干旱初期（停止浇水3 ~ 4 d），只有向日葵的土壤含水量（WC）和叶片RWC下降，干旱一般不影响抗氧化剂水平和胁迫参数。在干旱中期（停止浇水5 ~ 6 d），高粱和向日葵的土壤WC均下降，而叶片WC和RWC仅在向日葵中下降，干旱改变了向日葵和高粱中某些抗氧化剂的水平。在干旱后期（停止浇水7 ~ 8 d），高粱和向日葵土壤WC、叶片WC和RWC均有所下降，大部分参数受干旱影响。由于干旱的差异效应，干旱条件下高粱抗氧化剂水平并不总是高于或低于向日葵。这些结果表明，在干旱和水分条件下，高粱的抗氧化水平并不始终高于或低于向日葵，C3和C4植物对干旱的抗氧化反应存在差异。
To determine if antioxidant responses to drought differ between C3 and C4 plants, we grew Sorghum bicolor (C4 ) and Helianthus annuus (C3 ) under either watered or dry conditions in a growth chamber. Levels of leaf enzymatic antioxidants (ascorbate peroxidase, catalase, guaiacol peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase and superoxide dismutase), nonenzymatic antioxidants (ascorbate, glutathione and carotenoids) and stress parameters (Chl and malondialdehyde [MDA]) were determined. Under watered and drought conditions, Chl contents and leaf relative water contents (RWC) were higher in sorghum than in sunflower; however, MDA levels were higher in sunflower than in sorghum. Under watered conditions, inherent levels of antioxidants were not consistently higher or lower in sorghum than in sunflower. In response to drought, levels of antioxidants, Chl and MDA showed increase, decrease or remained unchanged depending on crop, duration of drought and kind of antioxidants. Duration of drought was divided arbitrarily into three stages. At an early stage of drought (watering had stopped for 3-4 d) when soil water content (WC) and leaf RWC had decreased only in sunflower, drought generally did not affect levels of antioxidants and stress parameters. At a middle stage of drought (watering had stopped for 5-6 d) when soil WC had decreased for both sorghum and sunflower but leaf WC and RWC had decreased only in sunflower, drought changed levels of some antioxidants in sunflower and sorghum. At a late stage of drought (watering had stopped for 7-8 d) when soil WC, leaf WC and RWC had decreased in sorghum and sunflower, most parameters studied were affected by drought. Because of the differential effect of drought, levels of antioxidants were not consistently higher or lower in sorghum than in sunflower under drought. These results show that, under both drought and watered conditions, sorghum does not have consistently higher or lower antioxidant levels than sunflower, and that antioxidant responses to drought differ in C3 and C4 plants.