The Endophytic Fungus Phomopsis liquidambari Increases Nodulation and N2Fixation in Arachis hypogaea by Enhancing Hydrogen Peroxide and Nitric Oxide Signalling.
The continuous cropping obstacles in monoculture fields are a major production constraint for peanuts. Application of the endophytic fungus Phomopsis liquidambari has increased peanut yields, and nodulation and N2fixation increases have been considered as important factors for P. liquidambari infection-improved peanut yield. However, the mechanisms involved in this process remain unknown. This work showed that compared with only Bradyrhizobium inoculation, co-inoculation with P. liquidambari significantly elevated endogenous H2O2and NO levels in peanut roots. Pre-treatment of seedlings with specific scavengers of H2O2(CAT) and NO (cPTIO) blocked P. liquidambari-induced nodulation and N2fixation. CAT not only suppressed the P. liquidambari-induced nodulation and N2fixation, but also suppressed the enhanced H2O2and NO generation. Nevertheless, the cPTIO did not significantly inhibit the induced H2O2biosynthesis, implying that H2O2acted upstream of NO production. These results were confirmed by observations that exogenous H2O2and sodium nitroprusside (SNP) reversed the inhibition of P. liquidambari-increased nodulation and N2fixation by the specific scavengers. The transcriptional activities of the symbiosis-related genes SymRK and CCaMK of peanut-Bradyrhizobium interactions also increased significantly in response to P. liquidambari, H2O2and SNP treatments. The pot experiment further confirmed that the P. liquidambari infection-enhanced H2O2and NO signalling pathways were significantly related to the increase in peanut nodulation and N2fixation. This is the first report that endophytic fungus P. liquidambari can increase peanut-Bradyrhizobium interactions via enhanced H2O2/NO-dependent signalling crosstalk, which is conducive to the alleviation of continuous cropping obstacles via an increase in nodulation and N2fixation.
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Xing-Guang
XG
Xie
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Wan-Qiu
WQ
Fu
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Feng-Min
FM
Zhang
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Xiao-Min
XM
Shi
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Ying-Ting
YT
Zeng
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Hui
H
Li
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China.
Wei
W
Zhang
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, No. 1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province, 210023, China. daichuanchao@njnu.edu.cn.
Chuan-Chao
CC
Dai
D010367:Arachis / Q000382:microbiology*; D001203:Ascomycota / Q000502:physiology*; D060026:Endophytes / Q000502:physiology; D006861:Hydrogen Peroxide / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D009586:Nitrogen Fixation; D055170:Plant Root Nodulation; D013559:Symbiosis
D009569:Nitric Oxide; D006861:Hydrogen Peroxide
Bradyrhizobium; Co-inoculation; Endophytic fungus Phomopsis liquidambari; H2O2 and NO signalling crosstalk; Nodulation and N2 fixation; Peanut