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

Wanggege Qin,Guangxi Wang,Shiping Liu,Chengxiong Liu,Yanhong Xue,Wei Jiang

doi:10.1186/s12866-019-1419-5

Wanggege Qin, Guangxi Wang + Show 4 more

Open Access

https://doi.org/10.1186/s12866-019-1419-5

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Journal: BMC microbiology	Publication Date: Feb 26, 2019
Citations: 43	License type: open-access

Affiliation: China Three Gorges University, Meijo University

Abstract

BackgroundDrought 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.ResultsOf 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.ConclusionThese 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.

Highlights

Drought and its resulting oxidative damage are the major yield limiting factors for crops in arid and semi-arid regions
The most effective strain was SG17, identified as an A. fumigatus [9], by which the effect was nearly equivalent to the positive control of Proline (Fig. 1)
We identified an antioxidant N-(4-hydroxystyryl) formamide (NFA) from the endophytic fungus A. fumigatus and found that it could maintain membrane integrity, and regulate the contents of NADPH oxidase, antioxidases and Heat shock proteins (HSP)

Summary

Introduction

Drought and its resulting oxidative damage are the major yield limiting factors for crops in arid and semi-arid regions. Over the past few decades, endophytic fungi have become a potential resource for development of new drugs [10, 23] They can improve the ability of plants to resist biotic or abiotic stresses [31, 38]. Drought is a yield limiting factor to rice [11, 15] Physiological indexes such as Proline (Pro) content, malondialdehyde (MDA) content, membrane relative permeability (MRP), relative water content (RWC) and antioxidant enzyme activity are closely involved in drought response [45]. ROS has a dual function in plants [24] On one hand, they can trigger oxidative bursts that improve resistance to stress [5]; on the other hand, they can induce membrane lipid peroxidation and cause a detrimental effect [33]. The dynamic equilibrium of ROS is crucial to plants, and the stronger the

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