A Novel Single-Site Mutation in the Catalytic Domain of Protoporphyrinogen Oxidase IX (PPO) Confers Resistance to PPO-Inhibiting Herbicides

Frontiers in Plant Science

Raphael A. Aponte¹  Michael Knapp¹  Thomas Mietzner¹  Aimone Porri¹  Ian R. Craig¹  Ana Claudia Langaro²  Gulab Rangani³  Matheus M. Noguera³  Nilda Roma-Burgos³  Reiofeli A. Salas-Perez³ 

[1] BASF SE, Ludwigshafen, Germany;Department of Crop Science, Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil;Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR, United States;

关键词: Amaranthus palmeri;    computational modeling;    cross-resistance;    Palmer amaranth;    PPO inhibitors;    PPO mutation;   

DOI  :  10.3389/fpls.2019.00568

来源: DOAJ

【 摘 要 】

Protoporphyrinogen oxidase (PPO)-inhibiting herbicides are used to control weeds in a variety of crops. These herbicides inhibit heme and photosynthesis in plants. PPO-inhibiting herbicides are used to control Amaranthus palmeri (Palmer amaranth) especially those with resistance to glyphosate and acetolactate synthase (ALS) inhibiting herbicides. While investigating the basis of high fomesafen-resistance in A. palmeri, we identified a new amino acid substitution of glycine to alanine in the catalytic domain of PPO2 at position 399 (G399A) (numbered according to the protein sequence of A. palmeri). G399 is highly conserved in the PPO protein family across eukaryotic species. Through combined molecular, computational, and biochemical approaches, we established that PPO2 with G399A mutation has reduced affinity for several PPO-inhibiting herbicides, possibly due to steric hindrance induced by the mutation. This is the first report of a PPO2 amino acid substitution at G399 position in a field-selected weed population of A. palmeri. The mutant A. palmeri PPO2 showed high-level in vitro resistance to different PPO inhibitors relative to the wild type. The G399A mutation is very likely to confer resistance to other weed species under selection imposed by the extensive agricultural use of PPO-inhibiting herbicides.

【 授权许可】

Unknown