A coumarin analogue NFA from endophytic Aspergillus fumigatus improves drought resistance in rice as an antioxidant

• Published in: BMC microbiology Vol. 19; no. 1; p. 50
• Main Authors: Qin, Wanggege, Liu, Chengxiong, Jiang, Wei, Xue, Yanhong, Wang, Guangxi, Liu, Shiping
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 26.02.2019; BioMed Central; BMC
• Subjects: Agricultural production; Antioxidant; Antioxidants; Antioxidants (Nutrients); Antioxidants - isolation & purification; Antioxidants - pharmacology; Arid regions; Arid zones; Aspergillus; Aspergillus fumigatus; Aspergillus fumigatus - chemistry; Coumarin; Coumarins; Coumarins - isolation & purification; Coumarins - pharmacology; Crop yield; Drought; Drought resistance; Drought stress; Droughts; Endophytes; Endophytes - chemistry; Endophytic fungus; Enzymatic activity; Enzyme activity; Enzymes; Flooding; Floods; Formamides - isolation & purification; Formamides - pharmacology; Fungi; Heat shock proteins; Limiting factors; Metabolism; Metabolites; Microbial drug resistance; NAD(P)H oxidase; Neurons; NFA; NMR; Nuclear magnetic resonance; Oryza; Oryza - drug effects; Oxidases; Oxidation resistance; Oxidative stress; Oxidative Stress - drug effects; Physiological aspects; Physiology; Plant growth; Plant Roots - microbiology; Plants (botany); Proteins; Reactive oxygen species; Rice; Riparian environments; Salinity; Semi arid areas; Semiarid lands; Stress response; Stress, Physiological - drug effects; Tamaricaceae - microbiology; Yellow River; Drought stress; NFA; Antioxidant; Aspergillus fumigatus; Endophytic fungus
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/s12866-019-1419-5

Drought and its resulting oxidative damage are the major yield limiting factors for crops in arid and semi-arid regions. Recent studies have found that endophytic fungi coexisting in plants can alleviate biotic or abiotic damage to plant growth and development. In order to screen for the endophytes associated with drought stress, 12 strains of endophytic fungi with high antioxidant activity isolated from riparian plants Myricaria laxiflora were evaluated for their effects in rice by the crude extracts. Of the 12 endophytic fungi, Aspergillus fumigatus SG-17 functioned most effectively, with the crude extract exhibiting relatively higher antioxidant capacity both in vivo and in vitro. The subsequent MS and NMR analysis showed that the primary substance responsible for the antioxidant activity in the extract was (Z)-N-(4-hydroxystyryl) formamide (NFA), an analogue of coumarin. Enzyme activity assay in nerve cells SH-SY5Y showed that NFA could maintain the membrane integrity and regulate the antioxidase activity under oxidative stress. In rice suffering drought stress, NFA effectively alleviated the harm by regulating the contents of NADPH oxidases, antioxidants and heat shock proteins, all of which are closely related with the reactive oxygen species pathway. These findings indicated that some endophytes from plants often subjected to flooding and oxidative stress could enhance drought resistance by producing compounds such as NFA to regulate the oxidative pathway.