The analysis of reference genes expression stability in susceptible and resistant Apera spica-venti populations under herbicide treatment.

Weed resistance to herbicides constitutes a serious problem to world crop production. One of the weeds that are significantly threatening the crops' yield and quality is Apera spica-venti. The target-site resistance (TSR) mechanism of A. spica-venti has been widely studied, though, little is known about its non-target-site resistance (NTSR) mechanisms at the molecular level. Molecular examination of NTSR is, to a great extent, based on the expression profiles of selected genes, e.g. those participating in detoxification. However, to obtain reliable results of gene expression analysis, the use of a normalizer is required. The aim of this study was to select the best reference genes in A. spica-venti plants of both populations, susceptible and resistant to ALS inhibitor, under treatment with herbicide. Eleven housekeeping genes were chosen for their expression stability assessment. The efficiency correction of raw quantification cycles (Cq) was included in the gene expression stability analyses, which resulted in indicating the TATA-box binding protein (TBP), glyceraldehyde-3-phosphate dehydrogenase, cytosolic (GAPC), and peptidyl-prolyl cis-trans isomerase CYP28 (CYP28) genes as the most stably expressed reference genes. The obtained results are of vital importance for future studies on the expression of genes associated with the non-target-site resistance mechanisms in the A. spica-venti populations susceptible and resistant to herbicides.