Screening of Endophytic Fungi in Locoweed Induced by Heavy-Ion Irradiation and Study on Swainsonine Biosynthesis Pathway

Yanan Mo; Zhen Yang; Baocheng Hao; Feng Cheng; Xiangdong Song; Xiaofei Shang; Haoxia Zhao; Ruofeng Shang; Xuehong Wang; Jianping Liang; Shengyi Wang; Yu Liu

doi:10.3390/jof8090951

Screening of Endophytic Fungi in Locoweed Induced by Heavy-Ion Irradiation and Study on Swainsonine Biosynthesis Pathway

J Fungi (Basel). 2022 Sep 10;8(9):951. doi: 10.3390/jof8090951.

Authors

Yanan Mo^{1

2

3}, Zhen Yang^{1

2

3}, Baocheng Hao^{1

2

3}, Feng Cheng^{1

2

3

4}, Xiangdong Song⁵, Xiaofei Shang^{1

2

3}, Haoxia Zhao^{1

2

3}, Ruofeng Shang^{1

2

3}, Xuehong Wang^{1

2

3}, Jianping Liang^{1

2

3}, Shengyi Wang^{1

2

3}, Yu Liu^{1

2

3

5}

Affiliations

¹ Key Laboratory of New Animal Drug Project, Lanzhou 730050, China.
² Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China.
³ Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agriculture Sciences, Lanzhou 730050, China.
⁴ Key Laboratory of Plant Resources and Chemistry in Arid Regions, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830000, China.
⁵ College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730050, China.

Abstract

Swainsonine (SW) is a substance with both animal neurotoxicity and natural anticancer activity produced by the metabolism of endophytic fungus Alternaria section Undifilum oxytropis of locoweed. This paper produced SW by fermentation of the endophytic fungus A. oxytropis of locoweed and obtained the optimal ultrasonic-assisted extraction process of SW by the response surface methodology. Meanwhile, four mutant strains with significant and stable SW-producing properties were screened out after the mutagenesis of A. oxytropis by heavy-ion irradiation. Of these, three were high-yielding stains and one was a low-yielding strain. In addition, through the analysis of metabolomics studies, it was speculated that the different SW production performance of the mutant might be related to the biosynthesis and utilization of L-lysine, L-2-aminoadipate-6-semialdehyde, etc. These results laid the foundation for the expansion of SW production, artificial construction of low-toxic locoweed and clarification of the SW biosynthesis pathway in A. oxytropis.

Keywords: Alternaria section Undifilum oxytropis; biosynthesis pathway; heavy-ion irradiation; metabonomics; swainsonine.

Grants and funding

This work was financially supported by Chinese Academy of Agricultural Sciences Innovative Project Veterinary Natural Medicine (No. 25-LZIHPS-03), Lanzhou Science and Technology Planning Project (No. 2018-1-114), Gansu Province Science and Technology Foundation Program for Youths (No. 21JR7RA034) and Major Output Scientific Research Items of Chinese Academy of Agricultural Sciences (No. CAAS-ZDRW202111).