Malone Jenna M, Dang Hue Thi, de Figueiredo Marcelo Ra, Gill Gurjeet, Gaines Todd A, Preston Christopher
School of Agriculture, Food and Wine, University of Adelaide, PMB1, Glen Osmond, Australia.
Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA.
Pest Manag Sci. 2025 Jun;81(6):3013-3019. doi: 10.1002/ps.8673. Epub 2025 Jan 29.
A deletion mutation in the degron tail of auxin coreceptor IAA2 was found to confer resistance to the herbicide 2,4-D in Sisymbrium orientale. Given the importance of auxin signalling in plant development, this study was conducted to investigate whether this deletion mutation may affect plant fitness.
The F progeny of crosses with two resistant populations P2 (P2♂ × S♀) and P13 (P13♂ × S♀) were used in this study. The F plants were grown under competition with wheat in pot-trials and evaluated for biomass and total seed production. Progeny of the F plants were phenotyped by application of 250 g a.e. ha 2,4-D and genotyped for the 27 bp deletion in IAA2. In a separate experiment, F and F recombinant inbred lines (RILs) with resistant and susceptible phenotypes were grown in monoculture and phenotyped over time for biomass and seed production. Wheat competition reduced biomass and seed production for all genotypes in each population and in each year. A density of 400 plants m of wheat reduced Sisymbrium orientale biomass by 76-78% in 2016 and by 59-63% in 2017 and total seed production by 80-83% and 60-64% by respective year. For the experiment involving resistant and susceptible RILs, biomass accumulation and seed production were the same between resistant and susceptible for both populations.
The 27 bp deletion in IAA2 in Sisymbrium orientale does not carry a measurable fitness penalty, as determined by biomass reduction or seed production, either in monoculture or in competition with wheat. As a result, this mutation is unlikely to decrease over time in weed populations if 2,4-D selection pressure were removed. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
在东方大蒜芥中发现生长素共受体IAA2的降解子尾部缺失突变可赋予对除草剂2,4 - D的抗性。鉴于生长素信号传导在植物发育中的重要性，本研究旨在调查这种缺失突变是否会影响植物适合度。
本研究使用了与两个抗性种群P2（P2♂×S♀）和P13（P13♂×S♀）杂交的F子代。F植株在盆栽试验中与小麦竞争生长，并对生物量和种子总产量进行评估。F植株的子代通过施用250 g a.e. ha的2,4 - D进行表型分析，并对IAA2中的27 bp缺失进行基因分型。在另一个实验中，具有抗性和敏感表型的F和F重组自交系（RIL）在单作条件下生长，并随时间对生物量和种子产量进行表型分析。小麦竞争降低了每个种群和每年所有基因型的生物量和种子产量。2016年，每平方米400株小麦的密度使东方大蒜芥生物量减少76 - 78%，2017年减少59 - 63%，种子总产量分别减少80 - 83%和60 - 64%。对于涉及抗性和敏感RIL的实验，两个种群的抗性和敏感植株之间的生物量积累和种子产量相同。
无论是在单作还是与小麦竞争的情况下，通过生物量减少或种子产量测定，东方大蒜芥IAA2中的27 bp缺失均未带来可测量的适合度损失。因此，如果去除2,4 - D选择压力，这种突变在杂草种群中不太可能随时间减少。© 2025作者。由John Wiley & Sons Ltd代表化学工业协会出版的《害虫管理科学》。
