Studies on the molecular basis of chitooligosaccharide signaling in the arbuscular mycorrhizal symbiosis

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H02548
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Bioorganic chemistry
• Research Institution: Osaka Prefecture University
• Principal Investigator: Akiyama Kohki 大阪府立大学, 生命環境科学研究科, 教授 (20285307)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: アーバスキュラー菌根菌 / Mycファクター / キトオリゴ糖 / ストリゴラクトン

Outline of Final Research Achievements

AM fungi had long been postulated to produce signal molecules called “Myc factors” that induce the molecular and cellular responses leading to successful root colonization by AM fungi. Lipochitooligosaccharides called Myc-LCOs and small chitin oligomers have been identified as Myc factors from the germinated spore exudates of the AM fungus Rhizophagus irregularis (Maillet et al., 2011, Genre et al., 2012). However, it was found that Myc-LCOs and chitin oligomers elicit only partial and limited induction of symbiotic responses in AM host plants. We previously showed that partially N-deacetylated chitin (DAC) trimers were strong inducers of AM symbiosis-related gene expression in rice roots and were secreted from R. irregularis. There are six possible isomers for DAC trimers. In this study, we identified a DAC trimer isomer, secreted by the AM fungus, acting as an inducer of AM-symbiotic responses in rice.

Free Research Field

天然物化学・生物有機化学

Academic Significance and Societal Importance of the Research Achievements

植物は共生菌や病原菌に由来する様々なキチン質オリゴ糖を識別して適切な共生・防御応答を示すと考えられている。生理活性オリゴ糖では鎖長が重要な構造的要素であり、一般に4糖以上のものが強い活性を示す。本研究で同定した短鎖のヘテロキトオリゴ糖やキトサンオリゴ糖は3糖が最も強い活性を示す。このような短鎖長のオリゴ糖の共生における関与は全く新規の発見であり、植物微生物相互作用研究において新たな展開をもたらすことが期待される。