Resistance determination of the ACCase-inhibiting herbicide of clodinafop propargyl in Avena ludoviciana (Durieu), and study of their interaction using molecular docking and simulation

Rapeseed Transformation with aroA Bacterial Gene Containing P101S Mutation Confers Glyphosate Resistance

Field weed infestations can cause serious problems and require regular and planned programs to control them. Glyphosate is a broad-spectrum herbicide that inactivates the 5-enolpyruvylshikimate 3-phosphate synthase (EPSPS) enzyme and causes plant death. It has been reported that the mutation of proline 101 to serine in EPSPS is one of the effective mutations to reduce the affinity of glyphosate to EPSPS enzyme. In this study, we investigated the effect of the bacterial P101S mutant aromatic acid (aroA) gene on glyphosate resistance in transgenic rapeseeds. For this purpose, the mutant gene was synthesized and cloned into the pUC18 and pBI121 vectors. The gene was transferred to rapeseed by the Agrobacterium-mediated method. In this experiment, three generations of transgenic plants (T0, T1, and T2) were studied under in vitro and in vivo conditions. After the treatment of 75 putative transgenic plants with 10 mM glyphosate in T0 generation, resistant plants were identified and their seeds were harvested. In the T1 generation, out of 200 cultivated plants, 141 showed resistance. After the plants were treated with herbicides and resistance was determined, the seeds were harvested when they mature. In the T2 generation, most plants (162 plants of 200) were resistant to glyphosate. Therefore, the inheritance of resistance followed Mendel's first law, which is a sign of the monogenic character of resistance. Purification and increasing the percentage of resistant plants will be carried out in the next generations. It is concluded that P101S mutation guarantees glyphosate resistance of rapeseed and is recommended to study it in other plants.

Purified Vitexin Compound 1 Inhibits UVA-Induced Cellular Senescence in Human Dermal Fibroblasts by Binding Mitogen-Activated Protein Kinase 1

Purified vitexin compound 1 (VB1), a novel lignanoid isolated from the seeds of the Chinese herb Vitex negundo, has strong antioxidant abilities and broad antitumor activities. However, little is known about its anti-photoaging effect on the skin and the underlying mechanism. Here, we demonstrated that VB1 significantly attenuates ultraviolet A (UVA)-induced senescence in human dermal fibroblasts (HDFs), as evidenced by senescence-associated β-gal staining, MTT assays, and western blot analysis of the expression of p16 and matrix metalloproteinase-1 (MMP-1). Furthermore, mass spectrometry revealed that VB1 could directly bind to Mitogen-Activated Protein Kinase 1 (MAPK1). Molecular docking and molecular dynamics simulation methods confirmed the mass spectroscopy results and predicted six possible binding amino acids of MAPK1 that most likely interacted with VB1. Subsequent immunoprecipitation analysis, including different MAPK1 mutants, revealed that VB1 directly interacted with the residues, glutamic acid 58 (E58) and arginine 65 (R65) of MAPK1, leading to the partial reversal of UVA-induced senescence in HEK293T cells. Finally, we demonstrated that the topical application of VB1 to the skin of mice significantly reduced photoaging phenotypes in vivo. Collectively, these data demonstrated that VB1 reduces UVA-induced senescence by targeting MAPK1 and alleviates skin photoaging in mice, suggesting that VB1 may be applicable for the prevention and treatment of skin photoaging.

PCR-based identification of point mutation mediating acetolactate synthase-inhibiting herbicide resistance in weed wild mustard (Sinapis arvensis)

Acetolactate synthase (ALS)-inhibiting herbicides have been widely used for effective management and control of wild mustard (Sinapis arvensis) biotypes in Iran. The resistance of the ALS inhibitor to weeds is attributed to either target site alteration or enhanced herbicide degradation. Molecular and genetic characterization of the resistance mechanism is relevant to the evolution and management of herbicide resistance. The aims of this research were (a) to characterize the mechanism molecular suspected to Granstar (tribenuron methyl) and Atlantis (Mesosulfuron + Iodosulfuron) resistance in S. arvensis biotypes in the greenhouse and laboratory (b) to investigate the organization of the target-site loci in field selected S. arvensis populations and (c) instantly recognize the mutations that cause resistance to ALS inhibitors. Eighty resistant populations of S. arvensis were carefully collected from fields repeatedly treated with Granstar and Atlantis. The resistance level and pattern of the population were determined through a greenhouse dose-response experiment by applying the above-mentioned herbicides. Extraction of genomic DNA was carried out for PCR and ALS gene analysis. Our results showed that by greenhouse experiment across 80 biotypes suspected to resistance collected in the fields of whole Kermanshah Province, 30 biotypes (37.5%) conferred S. arvensis resistance species reported in the farm. Among 30 biotypes screened in a greenhouse experiment, six biotypes (20%), No. 9, 14, 17, 19, 23 and 28 revealed a mutation in the ALS gene that was detected by PCR-based method. Biotype No. 9 in the position 376 (Asp376-Gly, GAC to GGC), biotypes 14 and 19 in the position 197 (Pro197-Ala, CCT to GCT), biotypes 17, 23 and 28 in the position 574 (Trp574-Leu, TGG to TTG) and biotype No. 23 in the position 122 (Thr-122-Ala, ACA to GCA) showed herbicide resistance. The specific mutation in the position of 122 of the ALS gene in S. arvensis is the first report. Other biotypes showed resistance in the greenhouse but didn't indicate any mutation by PCR-based method. Most of the resistance to Granstar and Atlantis are genetic and are induced by mutations in the ALS gene. The resistance to herbicides may contain a non-mutagenic and non-genetic origin. The reason of herbicide resistance as non-target-site in some of the biotypes may relate to the activity of the herbicide-metabolizing enzyme(s) or transporter proteins that will naturally lead to an increase in herbicide degradation or compartmentation away from its active site.