Extrachromosomal circular DNA–mediated spread of herbicide resistance in interspecific hybrids of pigweed

• Published in: Plant physiology (Bethesda) Vol. 193; no. 1; pp. 229 - 233
• Main Authors: Koo, Dal-Hoe, Sathishraj, Rajendran, Nakka, Sridevi, Ju, Yoonha, Nandula, Vijay K, Jugulam, Mithila, Friebe, Bernd, Gill, Bikram S
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 31.08.2023
• Subjects: Amaranthus - genetics; DNA; DNA Copy Number Variations; DNA, Circular; Herbicide Resistance - genetics; Herbicides - pharmacology; Humans; In Situ Hybridization, Fluorescence; Research Report
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1093/plphys/kiad281

Extrachromosomal circular DNA mediates the spread and rapid evolution of herbicide resistance in interspecific hybrids of pigweed. Abstract Extrachromosomal circular DNAs (eccDNAs) are found in many eukaryotic organisms. EccDNA-powered copy number variation plays diverse roles, from oncogenesis in humans to herbicide resistance in crop weeds. Here, we report interspecific eccDNA flow and its dynamic behavior in soma cells of natural populations and F1 hybrids of Amaranthus sp. The glyphosate-resistance (GR) trait is controlled by eccDNA-based amplification harboring the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (eccDNA replicon), the molecular target of glyphosate. We documented pollen-mediated transfer of eccDNA in experimental hybrids between glyphosate-susceptible Amaranthus tuberculatus and GR Amaranthus palmeri. Experimental hybridization and fluorescence in situ hybridization (FISH) analysis revealed that the eccDNA replicon in Amaranthus spinosus derived from GR A. palmeri by natural hybridization. FISH analysis also revealed random chromosome anchoring and massive eccDNA replicon copy number variation in soma cells of weedy hybrids. The results suggest that eccDNAs are inheritable across compatible species, contributing to genome plasticity and rapid adaptive evolution.