Niu Kuiju, Ma Xiang, Liang Guoling, Ma Huiling, Jia Zhifeng, Liu Wenhui, Yu Qianqian
Key Laboratory of Grassland Ecosystem of Ministry of Education, College of Grassland Science, Gansu Agricultural University, Lanzhou, 730070, People's Republic of China.
Academy of Animal Sciences and Veterinary, Qinghai University, Xining, 810016, People's Republic of China.
Protoplasma. 2017 Nov;254(6):2083-2094. doi: 10.1007/s00709-017-1101-4. Epub 2017 Mar 20.
Drought stress occurs frequently and severely as a result of global climate change, and it exerts serious effects on plants. 5-Aminolevulinic acid (5-ALA) plays a crucial role in conferring abiotic stress tolerance in plants. To enhance the drought tolerance of turfgrass and investigate the effects of 5-ALA on antioxidant metabolism and gene expression under drought stress conditions, exogenous 5-ALA was applied by foliar spraying before Kentucky bluegrass (Poa pratensis L.) seedlings were exposed to drought [induced by 10% polyethylene glycol (PEG)] stress for 20 days. 5-ALA pretreatment increased turf quality (TQ) and leaf relative water content (RWC) while reducing reactive oxygen species (ROS) production including HO content and O generation rate, lipoxygenase (LOX) activity, and malondialdehyde (MDA) content under drought stress. 5-ALA pretreatment maintained ascorbate (AsA) and glutathione (GSH) contents and the ASA/DHA and GSH/GSSG ratios at high levels, and it enhanced the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), dehydroascorbate reductase (DHAR), and glutathione reductase (GR), which are crucial for scavenging drought-induced ROS. In addition, 5-ALA upregulated the relative expression levels of Cu/ZnSOD, APX, GPX, and DHAR but downregulated those of CAT and GR under drought stress. These results indicated that the application of 5-ALA might improve turfgrass quality and promote drought tolerance in Kentucky bluegrass through reducing oxidative damage and increasing non-enzyme antioxidant levels and antioxidant enzyme activity at transcriptional and posttranscriptional levels.
由于全球气候变化，干旱胁迫频繁且严重发生，对植物产生严重影响。5-氨基乙酰丙酸（5-ALA）在赋予植物非生物胁迫耐受性方面起着关键作用。为提高草坪草的耐旱性并研究干旱胁迫条件下5-ALA对抗氧化代谢和基因表达的影响，在草地早熟禾（Poa pratensis L.）幼苗遭受干旱[由10%聚乙二醇（PEG）诱导]胁迫20天之前，通过叶面喷施施加外源5-ALA。5-ALA预处理提高了草坪质量（TQ）和叶片相对含水量（RWC），同时降低了干旱胁迫下活性氧（ROS）的产生，包括HO含量和O产生速率、脂氧合酶（LOX）活性以及丙二醛（MDA）含量。5-ALA预处理使抗坏血酸（AsA）和谷胱甘肽（GSH）含量以及ASA/DHA和GSH/GSSG比值维持在较高水平，并增强了超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、谷胱甘肽过氧化物酶（GPX）、脱氢抗坏血酸还原酶（DHAR）和谷胱甘肽还原酶（GR）的活性，这些酶对于清除干旱诱导的ROS至关重要。此外，在干旱胁迫下，5-ALA上调了Cu/ZnSOD、APX、GPX和DHAR的相对表达水平，但下调了CAT和GR的相对表达水平。这些结果表明，施用5-ALA可能通过减少氧化损伤、在转录和转录后水平提高非酶抗氧化剂水平和抗氧化酶活性来改善草坪草质量并促进草地早熟禾的耐旱性。
