0000000001100435
AUTHOR
Arnaud Duhoux
Characterisation of rye-grass (Lolium sp.) transcriptome-wide response to ALS-inhibiting herbicides
International audience; Non-target-site-resistance (NTSR) to herbicides is a major cause for failure in the chemical control of a number of weeds, and is especially widespread and important in grass weeds. Although several gene families have been shown to be involved in NTSR (cytochromes p450, glutathione-S-transferases, glycosyl-transferases, ABC transporters, esterases…), the genetic determinants of NTSR are still poorly known to date. NTSR is part of the response of weeds to herbicides. To unravel NTSR, it is thus of interest to firstly characterise the processes involved in herbicide stress response in grasses. For this purpose, we implemented a comparative whole-transcriptome sequencin…
Identification de gènes liés à la résistance aux herbicides non liée à la cible chez les Ivraies : vers des tests « moléculaires » de diagnostic
Identification of genes linked to non-target-site resistance to herbicides in ryegrass : towards "molecular" diagnosis assays. Setting up molecular diagnosis tools would greatly foster preventing and managing non-target-sitebased resistance to herbicides (NTSR). This is currently hampered by the complexity of NTSR genetic determinism, which is largely based upon differences in the expression of an unknown number of genes between resistant and sensitive plants. Identifying NTSR genes is thus a challenging task. Herein, we report the identification of 19 genes which expression patterns are correlated to NTSR to ALS-inhibiting herbicides in rye-grasses (Lolium sp.). We demonstrate the potentia…
Les phytoprotecteurs (« Safeners ») associés aux herbicides jouent-ils un rôle dans la sélection de résistances non liées à la cible ?
Do herbicide-associated "Safeners" play a role in the selection for non-target-site resistances ? To ensure or improve crop selectivity, some herbicide molecules are applied in association with a “safener”. Safeners are compounds that, at the rate applied, enhance herbicide-degrading metabolic pathways supposedly specifically in crop plants. The metabolic pathways enhanced by safeners in crop plants are highly similar to those exacerbated in taxonomically closely related weed species that evolved non-target-site based resistance (NTSR) to herbicides. Herein, we show an enhancing effect of herbicide safeners on NTSR in a major noxious grass weed: rye-grass (Lolium sp.).
Three cytochrome P450 genes are over-expressed in ryegrass (Lolium sp.) plants resistant to the ALS inhibitors iodosulfuron+mesosulfuron or pyroxsulam.
One of the most intense abiotic stresses encountered by arable weeds infesting agricultural fields is herbicide application. Non-target-site based resistance (NTSR), which belongs to the weed herbicide stress response pathways, is an adaptive response to herbicides. Stress response is driven by gene regulation. It follows that NTSR is endowed by differences in the expression of a set of genes between sensitive and resistant plants. We developed an accurate and reliable quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay to detect differences in gene expression in the major grass weed Lolium sp. using two ALS inhibitors (iodosulfuron+mesosulfuron and pyroxsulam). Res…
Diagnosis of non target site based resistance within rye grass(Lolium sp): development of quick and reliable tests
Non target site resistance (NTSR) is the major threat for effective herbicide-based control of grass weeds. NTSR, still largely unknown, is endowed by the regulation of a subset of the genes involved in the response of the weed to herbicide treatment. This study aims at identifying NTSR genes in rye-grass to develop resistance diagnosis tests. The transcriptome of plants resistant or sensitive to ALS inhibitors collected before and after herbicide application was sequenced using a deep sequencing technology. We identified genes differentially expressed between resistant and sensitive plants. We developed a RT-qPCR test to measure gene expression levels in individual plants from several popu…
Genetic determinisms, evolution and detection of non-target-site based resistance to herbicides inhibiting acetolactate-synthase in rye-grass (Lolium sp.)
The aim of this study is to unravel the genetic determinism of non-target-site resistance (NTSR) to herbicides inhibiting acetolactate-synthase (ALS) in the major weed rye-grass (Lolium sp.), and to estimate the feasibility of NTSR diagnosis based on genetic data. On the one hand, this work contributes to the understanding of the processes driving the evolution of NTSR to herbicides, and on the other hand it lays the foundations for the development of a diagnosis tool to identify NTSR to ALS inhibiting herbicides. - Using a quantitative transcriptome sequencing approach, we showed that NTSR evolve by recurrent selection of higher and higher constitutive expression levels of genes involved i…