Recurrent Selection with Sub-Lethal Doses of Mesotrione Reduces Sensitivity in .

, ranked as the most prolific and troublesome weed in North America, has evolved resistance to several herbicide sites of action. Repeated use of any one herbicide, especially at lower than recommended doses, can lead to evolution of weed resistance, and, therefore, a better understanding of the process of resistance evolution is essential for the management of and other difficult-to-control weed species. rapidly developed resistance to 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors such as mesotrione.

Physical Mapping of Amplified Copies of the 5-Enolpyruvylshikimate-3-Phosphate Synthase Gene in Glyphosate-Resistant Amaranthus tuberculatus.

Recent and rapid evolution of resistance to glyphosate, the most widely used herbicides, in several weed species, including common waterhemp (Amaranthus tuberculatus), poses a serious threat to sustained crop production. We report that glyphosate resistance in A tuberculatus was due to amplification of the 5-enolpyruvylshikimate-3-P synthase (EPSPS) gene, which encodes the molecular target of glyphosate. There was a positive correlation between EPSPS gene copies and its transcript expression.

Field-evolved resistance to four modes of action of herbicides in a single kochia (Kochia scoparia L. Schrad.) population.

Background: Evolution of multiple herbicide resistance in weeds is a serious threat to weed management in crop production. Kochia is an economically important broadleaf weed in the U.S.

Tandem amplification of a chromosomal segment harboring 5-enolpyruvylshikimate-3-phosphate synthase locus confers glyphosate resistance in Kochia scoparia.

Recent rapid evolution and spread of resistance to the most extensively used herbicide, glyphosate, is a major threat to global crop production. Genetic mechanisms by which weeds evolve resistance to herbicides largely determine the level of resistance and the rate of evolution of resistance. In a previous study, we determined that glyphosate resistance in Kochia scoparia is due to the amplification of the 5-Enolpyruvylshikimate-3-Phosphate Synthase (EPSPS) gene, the enzyme target of glyphosate.

Ripening, storage temperature, ethylene action, and oxidative stress alter apple peel phytosterol metabolism.

The chilling conditions of apple cold storage can provoke an economically significant necrotic peel disorder called superficial scald (scald) in susceptible cultivars. Disorder development can be reduced by inhibiting ethylene action or oxidative stress as well as intermittent warming. It was previously demonstrated that scald is preceded by a metabolomic shift that results in altered levels of various classes of triterpenoids, including metabolites with mass spectral features similar to β-sitosterol.