The Phytotoxin Myrigalone A Triggers a Phased Detoxification Programme and Inhibits Lepidium sativum Seed Germination via Multiple Mechanisms Including Interference with Auxin Homeostasis

0561528 - ÚEB 2023 RIV CH eng J - Journal Article
Nakabayashi, K. - Walker, M. - Irwin, D. - Cohn, J. - Guida-English, S. M. - Garcia, L. - Pavlović, Iva - Novák, Ondřej - Tarkowská, Danuše - Strnad, Miroslav - Pérez, M. - Seville, A. - Stock, D. - Leubner-Metzger, Gerhard
The Phytotoxin Myrigalone A Triggers a Phased Detoxification Programme and Inhibits Lepidium sativum Seed Germination via Multiple Mechanisms Including Interference with Auxin Homeostasis.
International Journal of Molecular Sciences. Roč. 23, č. 9 (2022), č. článku 4618. E-ISSN 1422-0067
R&D Projects: GA MŠMT(CZ) EF16_019/0000827; GA MŠMT(CZ) EF16_019/0000738
Institutional support: RVO:61389030
Keywords : allelochemical and allelopathy * aquaporin-mediated water transport * ATP-binding cassette (ABC) transporter * auxin transport and homeostasis * cis-(+)-12-ox-ophytodienoic acid (OPDA) reductase * gibberellin metabolism * phytotoxin detoxification programme * PIN auxin efflux carrier * seed germination * WRKY transcription factors
OECD category: Biochemistry and molecular biology
Impact factor: 5.6, year: 2022
Method of publishing: Open access
https://doi.org/10.3390/ijms23094618

Molecular responses of plants to natural phytotoxins comprise more general and com-pound-specific mechanisms. How phytotoxic chalcones and other flavonoids inhibit seedling growth was widely studied, but how they interfere with seed germination is largely unknown. The dihydrochalcone and putative allelochemical myrigalone A (MyA) inhibits seed germination and seedling growth. Transcriptome (RNAseq) and hormone analyses of Lepidium sativum seed responses to MyA were compared to other bioactive and inactive compounds. MyA treatment of im-bibed seeds triggered the phased induction of a detoxification programme, altered gibberellin, cis- (+)-12-oxophytodienoic acid and jasmonate metabolism, and affected the expression of hormone transporter genes. The MyA-mediated inhibition involved interference with the antioxidant system, oxidative signalling, aquaporins and water uptake, but not uncoupling of oxidative phosphoryla-tion or p-hydroxyphenylpyruvate dioxygenase expression/activity. MyA specifically affected the expression of auxin-related signalling genes, and various transporter genes, including for auxin transport (PIN7, ABCG37, ABCG4, WAT1). Responses to auxin-specific inhibitors further supported the conclusion that MyA interferes with auxin homeostasis during seed germination. Comparative analysis of MyA and other phytotoxins revealed differences in the specific regulatory mechanisms and auxin transporter genes targeted to interfere with auxin homestasis. We conclude that MyA exerts its phytotoxic activity by multiple auxin-dependent and independent molecular mechanisms.
Permanent Link: https://hdl.handle.net/11104/0334115