Exogenous 5-aminolevulinic acid alleviates the detrimental effects of UV-B stress on lettuce (Lactuca sativa L) seedlings

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• 作者：Ozkan Aksakal ; Omer Faruk Algur ; Feyza Icoglu Aksakal…
• 关键词：5 ; Aminolevulinic acid ; Antioxidant enzymes ; Gene expression ; γ ; Tocopherol methyltransferase ; Phenylalanine ammonia lyase ; Ultraviolet ; B
• 刊名：Acta Physiologiae Plantarum
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：39
• 期：2
• 全文大小：
• 刊物主题：Plant Physiology; Plant Genetics & Genomics; Plant Biochemistry; Plant Pathology; Plant Anatomy/Development; Agriculture;
• 出版者：Springer Berlin Heidelberg
• ISSN：1861-1664
• 卷排序：39

文摘

One of the abiotic stress factors affecting plant metabolism is ultraviolet-B (UV-B) radiation. 5-Aminolevulinic acid (ALA), a key precursor of porphyrin biosynthesis, promotes plant growth and crop yields. To investigate the alleviating effects of exogenous ALA on the damages caused by UV-B exposure, two different concentrations [10 ppm (ALA1) and 25 ppm (ALA2)] of ALA were applied to lettuce seedlings for 24 h and then they were exposed to 3.3 W m−2 UV-B. Results showed that UV-B treatment significantly decreased chlorophyll a and b (Chl a and b) concentration, enhanced the activity of antioxidant enzymes, total phenolic concentration, soluble sugar contents, expression of phenylalanine ammonia lyase (PAL) and γ-tocopherol methyltransferase (γ-TMT) genes, the concentration of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and the rate of superoxide radical (\({\text{O}}_{2}^{ - }\)) generation in the lettuce seedlings when compared to the control. Pre-treatment with exogenous ALA significantly enhanced UV-B stress tolerance in lettuce seedlings by decreasing the reactive oxygen species. On the other hand, ALA application caused more increases in the PAL and γ-TMT gene expression, antioxidant enzymes activities, Chl a and b concentration, total phenolic content, antioxidant capacity and the concentrations of soluble sugars. Obtained results indicated that UV-B radiation exerts an adverse effect on lettuce seedlings, and some of the negative effects of UV-B radiation can be alleviated by exogenous ALA.