Effect of proline on biochemical and molecular mechanisms in lettuce (Lactuca sativa L.) exposed to UV-B radiation
Effect of proline on biochemical and molecular mechanisms in lettuce (Lactuca sativa L.) exposed to UV-B radiation
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DOI：
10.1039/c6pp00412a
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发表时间：
2017-02-01
影响因子：
3.1
通讯作者：
Esim, Nevzat
中科院分区：
文献类型：
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作者：
Aksakal, Ozkan;Tabay, Dilruba;Esim, Nevzat
研究了脯氨酸（Pro）对UV-B辐射诱导的生菜氧化胁迫的缓解作用。在用20 mM Pro预处理后，将莴苣幼苗暴露于3.3 W m（-2）UV-B辐射12 h。结果表明，在不同的处理条件下，随着处理时间的延长，丙二醛（MDA）、过氧化氢（H2 O2）、内源脯氨酸（Pro）含量、抗氧化酶[超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和过氧化物酶（POD）]活性、总酚含量、抗氧化能力、苯丙氨酸解氨酶（PAL）、γ-生育酚甲基转移酶（γ-生育酚甲基转移酶）表达量均呈下降趋势，（γ-TMT）和脯氨酸脱氢酶（ProDH）基因，记录脱落酸（阿坝）、赤霉酸（GA）、吲哚乙酸（IAA）和水杨酸（SA）等植物激素水平以及可溶性糖和有机酸。结果表明，脯氨酸能降低生菜幼苗的脂质过氧化反应和H2 O2含量，提高内源脯氨酸水平、抗氧化酶活性、总酚含量和抗氧化能力，从而减轻生菜幼苗的氧化损伤。此外，外源Pro处理还提高了GA、IAA、可溶性糖和有机酸的含量以及PAL、γ-TMT和ProDH基因的表达。本研究结果表明，外源Pro预处理通过调节UV-B响应的生化机制，对提高莴苣的UV-B耐性有重要贡献。
The purpose of the present study was to evaluate the role of proline (Pro) in relieving UV-B radiation-induced oxidative stress in lettuce. Lettuce seedlings were exposed to 3.3 W m(-2) UV-B radiation for 12 h after pre-treatment sprayed with 20 mM Pro. The data for malondialdehyde (MDA), hydrogen peroxide (H2O2), endogenous Pro level, the activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD)], total phenolic concentration, antioxidant capacity, expression of phenylalanine ammonia lyase (PAL), gamma-tocopherol methyltransferase (gamma-TMT) and proline dehydrogenase (ProDH) genes, phytohormone levels such as abscisic acid (ABA), gibberellic acid (GA), indole acetic acid (IAA) and salicylic acid (SA), soluble sugars and organic acids were recorded. It was found that Pro alleviated the oxidative damage in the seedlings of lettuce as demonstrated by lower lipid peroxidation and H2O2 content, increasing the endogenous Pro level, the activity of antioxidant enzymes, total phenolic concentration and the antioxidant capacity. Additionally, it was revealed that exogenous application of Pro enhanced the levels of GA, IAA, the concentrations of soluble sugars and organic acids and expressions of PAL, gamma-TMT and ProDH genes as compared to the control. The results obtained in this study suggest that pre-treatment with exogenous Pro provides important contributions to the increase in the UV-B tolerance of lettuce by regulating the biochemical mechanisms of UV-B response.