Dehydrative Alkylation of Phenols with Alcohols via Formation of Triflate.

An efficient synergistic trityl cation ([Ph3C][B(C6F5)4])/triflic anhydride (Tf2O) catalyzed alkylation of phenols with alcohols is reported. Benefiting from the formation of the triflate in situ, cheap and readily available active alcohols can be used as the alkylating reagents, and the reaction proceeds under mild reaction conditions with a broad substrate scope. This protocol enables the synthesis of ortho-selective phenols and 2,4,6-trisubstitued phenols containing three different alkyl groups. tert-Amyl triflate was synthesized, and mechanistic studies support a triflate-mediated alkylation process.

Visual Pathway Recovery Post Pituitary Adenoma Surgery: Insights from Retinal Structure, Vascular Density, and Neural Conduction Analysis.

INTRODUCTION: This study investigates how surgery for pituitary adenoma (PA) affects the visual pathway, examining changes in the retina, blood vessel density, and nerve function. Since PAs often impair vision as a result of their location near visual structures, this research is key to understanding and improving vision recovery after surgery. METHODS: Our study is based on a retrospective analysis of the historical data of 28 patients diagnosed with pituitary adenomas. We conducted assessments by reviewing preoperative and postoperative imaging records. These included optical coherence tomography (OCT) for retinal structure analysis, diffusion tensor imaging (DTI) for neural transmission evaluation, and optical coherence tomography angiography for assessing blood vessel density. These tools allowed for a detailed understanding of the structural and functional changes within the visual pathway following PA surgery. RESULTS: OCT findings show postoperative changes in the eye: thinning in average and nasal circumpapillary retinal nerve fiber layer, thickening in macular central 1 mm inner plexus layer, ganglion cell complex, and nasal retinal nerve fiber layer. DTI reveals increased fractional anisotropy (FA) in the left optic chiasm and posterior optic nerve, decreased mid-segment optic nerve FA, and increased apparent diffusion coefficient (ADC) in the right optic chiasm and nerve segments. Early postoperative reduction in radial peripapillary capillaries plexus density is noted. Preoperative ganglion cell layer (GCL) thickness correlates with postoperative visual radiation FA and ADC values, especially in the inferior quadrant. A negative correlation exists between preoperative GCL thickness and postoperative visual field mean defect values, particularly on the temporal side and superior inner ring. All changes are statistically significant (P < 0.05). CONCLUSIONS: The study finds that surgery for PA has varied effects on vision. Early post surgery, there are changes in the retina and nerve signals. Macular GCL thickness before surgery might predict early visual recovery, influencing future research and treatment for vision issues related to PA.

A multidimensional optimization strategy of pyraclostrobin-loaded microcapsules to improve the selectivity between toxicological risk in zebrafish and efficacy in controlling rice blast.

Developing microcapsules (MCs) delivery systems can effectively mitigate toxicological risk of highly active/toxic pesticides; whereas the controlled release functions also limiting their practical effectiveness. Therefore, designing a precise regulating strategy to balance the toxicity and bioactivity of MCs is urgently needed. Here, we prepared a series of pyraclostrobin-loaded MCs with different wall materials, particle sizes, core density and shell compactness using interfacial polymerization. The results showed that the MCs released more slowly in water with increasing particle sizes and capsule compactness, and they sunk more quickly with the increasing particle sizes and core density. Additionally, MCs with slower release speed was always accompanied with lower acute toxicity levels to zebrafish. When the release dynamics slowed down to the threshold dose on demand for disease control, facilitating settlement of MCs can further reduce toxicity within spatial and temporal dimensions. The poor accumulation of MCs with larger particle sizes or dense shell in gills was closely related to their efficient detoxification. Importantly, seven of the MCs samples possessed superior selectivity between bio-performance in controlling rice blast and toxicological hazard to fish compared to commercial formulations. The results provide a comprehensive guidance for developing an efficient and safe pesticide delivery system.

Multiple Metabolic Enzymes Can Be Involved in Cross-Resistance to 4-Hydroxyphenylpyruvate-Dioxygenase-Inhibiting Herbicides in Wild Radish.

A wild radish population (R) has been recently confirmed to be cross-resistant to 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides without previous exposure to these herbicides. This cross-resistance is endowed by enhanced metabolism. Our study identified one 2-oxoglutarate/Fe(II)-dependent dioxygenase gene (Rr2ODD1) and two P450 genes (RrCYP704C1 and RrCYP709B1), which were significantly more highly expressed in R versus susceptible (S) plants. Gene functional characterization using Arabidopsis transformation showed that overexpression of RrCYP709B1 conferred a modest level of resistance to mesotrione. Ultra-performance liquid chromatography-tandem mass spectrometry analysis showed that tissue mesotrione levels in RrCYP709B1 transgenic Arabidopsis plants were significantly lower than that in the wild type. In addition, overexpression of Rr2ODD1 or RrCYP704C1 in Arabidopsis endowed resistance to tembotrione and isoxaflutole. Structural modeling indicated that mesotrione can bind to CYP709B1 and be easily hydroxylated to form 4-OH-mesotrione. Although each gene confers a modest level of resistance, overexpression of the multiple herbicide-metabolizing genes could contribute to HPPD-inhibiting herbicide resistance in this wild radish population.

Aldo-keto reductase may contribute to glyphosate resistance in Lolium rigidum.

BACKGROUND: We have previously demonstrated that an aldo-keto reductase (AKR) from Echinochloa colona (EcAKR4-1) can metabolize glyphosate and confers glyphosate resistance. This study aims to investigate if the EcAKR4-1 orthologs from Lolium rigidum also play a role in glyphosate resistance in non-target-site based, glyphosate-resistant (R) L. rigidum populations from Western Australia. RESULTS: The full-length L. rigidum AKR gene (LrAKR4C10) orthologous to EcAKR4-1, together with a distinct LrAKR1, were cloned from plants of a glyphosate-susceptible (S) (VLR1) and three glyphosate R L. rigidum populations (WALR50, WALR60 and WALR70). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) results showed that basal expression levels of the two LrAKR genes did not differ between the R and S populations, but their expression was significantly induced by glyphosate (up to 4.3-fold) or 2,4-D treatment (up to 3.4-fold) in R populations. Escherichia coli cells transformed respectively with LrAKR4C10 and LrAKR1 were more tolerant to glyphosate. Rice (Oryza sativa) seedlings overexpressing each of the two LrAKR gene survived glyphosate rates that were lethal to the green fluorescence protein (GFP) control plants. Structural modeling predicts a similar way of glyphosate binding and detoxification by LrAKR4C10 and EcAKR4-1, but an alternative way of glyphosate binding by LrAKR1. Relatively lower capacity of the two LrAKRs in conferring glyphosate resistance than the known EcAKR4-1 was discussed in relation to structural interaction. CONCLUSION: Glyphosate-induced higher expression of the two LrAKR genes in L. rigidum populations contributes to a moderate level of glyphosate resistance likely through enhanced glyphosate metabolism. The herbicide 2,4-D can also induce the LrAKR expression, indicating the potential antagonistic effect of 2,4-D to glyphosate. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluating the role of SARS-CoV-2 target genes based on two nucleic acid assay kits.

Background: Effective isolation and early treatment of coronavirus disease 2019 (COVID-19) relies on rapid, accurate, and straightforward diagnostic tools. In response to the rapidly increasing number of cases, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assays for multiple target genes have become widely available in the market. Methods: In total, 236 COVID-19 patients with positive results in both RT-qPCR and rapid antigen diagnosis (Ag-RDT) were enrolled in the study. The cycle threshold (Ct) was compared with different onset times and target genes. Comparison between groups was evaluated with the Kruskal-Wallis test and Dunn test. The correlation between target genes was analyzed by Spearman. Results: In samples of Ct ≤ 21, Ct was different for the nucleocapsid (N), open reading frame 1ab (ORF1ab), and envelope (E) genes (P < 0.05). Mild COVID-19 patients within 7 days of onset accounted for 67.80% of all enrolled patients. At the above stage, all target genes reached the trough of Ct, and N genes showed lower values than the other target genes. The Ct of the ORF1ab and N gene in asymptomatic patients differed from those of mild patients within 7 days and more than 14 days of onset. The kits used in the study showed strong consistency among target genes, with all correlation coefficients >0.870. Conclusion: RT-qPCR confirmed that the N gene performed well in Ct ≤ 21 and samples within 7 days of onset. Ag-RDT was discriminatory for patients within 7 days of onset. This study facilitated early identification and control of COVID-19 prevalence among patients.

First report of Ustilago planetellacausing Smut on Eragrostis japonica (Thunb.) Trin in central region of China.

Eragrostis japonica (Thunb.) Trin, a kind of grass weeds in paddy rice fields, has recently been developing rapidly as the most harmful weed for rice production in addition to Echinochloa crusgalli and Leptochloa chinensis in partial areas of Anhui, Jiangsu, and Zhejiang provinces (Zhou et al.). In September 2019, inflated sori in the ovaries of E. japonica were identified in fields in Chuzhou County, Anhui Province. The disease incidence was approximately 50% at the survey site. Smut sori were in some spikelets of infected inflorescence destroying the inner most floral organs. Sori were ovoid and initially covered with a thin peridium (Figure 1). The sori busted after maturation, and the black powdery spores spread to the plant and soil. The sori were crushed using the sterilized tweezers. The black powdery spores were suspended with sterilized water and spread onto potato dextrose agar (PDA) medium. Spores were covered with spines, and the shape of spores varied from globose to ovoid. Scanning electron microscope was used to observe the morphology of spores. The spores were 7.5-12.3 µm × 5.8-11.8 µm (n=50). The surface of spores was covered with spines, and dense verruca were identified between the spines (Figure 2). For molecular identification, the primers ITS1/ITS4 and GAPDH-F/R were employed to amplify the rDNA region. The resulting sequences from the studied material were submitted to Genbank (MW819938 and MZ508441). BLASTn analysis revealed that ITS sequence shared 99% similarity with EF040584 (719/728) the ITS sequence from type specimen of Ustilago planetella. Based on the above results, the pathogen was identified as Ustilago planetella (Vánky, 2007). To verify the Koch's postulates, a pathogenicity test was performed by infiltrating the inflorescence with microspore suspensions of the strain SMZF-2 (1×106 spores/mL) when the E. japonica flowers for 30 minutes. The plants were inoculated in a moist chamber (with a relative humidity >80%) with a 12-h light cycle at 28℃. Inflated sori were observed after inoculated for 2 weeks, and U. planetella was isolated and identified with the methods described above. No sori were observed in the water-inoculated control plants. U. planetella had been reported to infect Eragrostis japonica in Thailand (Vánky, 2007). To our knowledge, this is the first report of U. planetella causing Smut on E. japonica (Thunb.) Trin in central region of China. The current study may help solve the negative effect of E. japonica in paddy rice production via using U. planetella in the future.

Hidden RNA pairings counteract the "first-come, first-served" splicing principle to drive stochastic choice in Dscam1 splice variants.

Drosophila melanogaster Dscam1 encodes 38,016 isoforms via mutually exclusive splicing; however, the regulatory mechanism behind this is not fully understood. Here, we found a set of hidden RNA secondary structures that balance the stochastic choice of Dscam1 splice variants (designated balancer RNA secondary structures). In vivo mutational analyses revealed the dual function of these balancer interactions in driving the stochastic choice of splice variants, through enhancement of the inclusion of distal exon 6s by cooperating with docking site-selector pairing to form a stronger multidomain pre-mRNA structure and through simultaneous repression of the inclusion of proximal exon 6s by antagonizing their docking site-selector pairings. Thus, we provide an elegant molecular model based on competition and cooperation between two sets of docking site-selector and balancer pairings, which counteracts the "first-come, first-served" principle. Our findings provide conceptual and mechanistic insight into the dynamics and functions of long-range RNA secondary structures.

Palladium-Catalyzed Decarbonylative Borylation of Aryl Anhydrides.

A palladium-catalyzed base-free decarbonylative borylation of aryl anhydrides has been developed. Catalyst system consisting of Pd(OAc)2/dppb enables readily available aryl anhydrides to be employed as electrophiles for the synthesis of versatile arylboronate esters via O-C(O) bond activation and decarbonylation. This method is characterized by an excellent functional group tolerance and broad substrate scope, using bench stable aryl anhydrides as aryl electrophiles in C-B bond formation. Mechanistic studies and functionalization of late-stage pharmaceutical molecules are disclosed.

Intron-targeted mutagenesis reveals roles for Dscam1 RNA pairing architecture-driven splicing bias in neuronal wiring.

Drosophila melanogaster Down syndrome cell adhesion molecule (Dscam1) can generate 38,016 different isoforms through largely stochastic, yet highly biased, alternative splicing. These isoforms are required for nervous functions. However, the functional significance of splicing bias remains unknown. Here, we provide evidence that Dscam1 splicing bias is required for mushroom body (MB) axonal wiring. We generate mutant flies with normal overall protein levels and an identical number but global changes in exon 4 and 9 isoform bias (DscamΔ4D-/- and DscamΔ9D-/-), respectively. In contrast to DscamΔ4D-/-, DscamΔ9D-/- exhibits remarkable MB defects, suggesting a variable domain-specific requirement for isoform bias. Importantly, changes in isoform bias cause axonal defects but do not influence the self-avoidance of axonal branches. We conclude that, in contrast to the isoform number that provides the molecular basis for neurite self-avoidance, isoform bias may play a role in MB axonal wiring by influencing non-repulsive signaling.

The role of FOLFIRINOX in metastatic pancreatic cancer: a meta-analysis.

BACKGROUND: The prognosis of pancreatic cancer (PC) is extremely poor, and most patients with metastatic PC still receive palliative care. Here, we report the efficacy and safety of FOLFIRINOX (oxaliplatin, irinotecan, leucovorin, 5-fluorouracil) in the treatment of metastatic PC. METHODS: We searched PubMed, Web of Science, EBSCO, and Cochrane library databases for articles that described efficacy and safety of FOLFIRINOX in patients with metastatic PC, from January 1996 to July 2020. The primary outcomes targeted included overall survival (OS) and progression-free survival (PFS). RESULTS: We found that FOLFIRINOX could directly improve OS rate of patients with metastatic PC (HR 0.76, 95% Cl 0.67-0.86, p<0.001) but had no benefit on PFS. Results from subgroup analyses showed that FOLFIRINOX had superior benefits than monochemotherapy (HR 0.59, 95% Cl 0.52-0.67, p<0.001), followed by FOLFIRINOX versus combination chemotherapy (HR 0.76, 95% Cl 0.61-0.95, p<0.001). The result of FOLFIRINOX versus nab-paclitaxel + gemcitabine had no benefit (HR 0.91, 95% Cl 0.82-1.02, p>0.05). The main adverse events (AEs) targeted hematological toxicity and the gastrointestinal system, and included febrile neutropenia, a reduction in white blood cells and appetite, as well as diarrhea. CONCLUSION: These findings indicated that FOLFIRINOX has potential benefits for the prognosis of patients with metastatic PC. Furthermore, there is no difference between the regimen of FOLFIRINOX and nab-paclitaxel + gemcitabine in this study. The application of FOLFIRINOX should be according to the actual situation of the patients and the experience of the doctors.

Overexpression of AGAMOUS-like gene PfAG5 promotes early flowering in Polypogon fugax.

Herbicides are the major tool for controlling large populations of yield depleting weeds. However, over-reliance on herbicides has resulted in weed adaptation and herbicide resistance. In recent years, early flowering weed species related to herbicide resistance is emerging, which may cause seed loss before crop harvest, creating a new problem for non-chemical weed management. In this study, a homologue gene of AGAMOUS sub-family (referred to as PfAG5) of the MADS-box family was cloned from plants of an early flowering Polypogon fugax Nees ex Steud. population resistant to the ACCase inhibitor herbicide (clodinafop-propargyl). The PfAG5 gene was functionally characterised in Arabidopsis thaliana L. Overexpression of the PfAG5 gene in Arabidopsis resulted in early flowering, abnormal flowers (e.g. small petals), short plants and reduced seed set, compared with the wild type. The expression of the PfAG5 gene was high in leaves and flowers, but low in pods in transgenic Arabidopsis. The PfAG5 gene was expressed earlier and higher in the resistant (R) than the susceptible (S) P. fugax plants. Furthermore, one protein (FRIGIDA-like) with relevance to flowering time regulation and interacts with PfAG5 in resistant (R) P. fugax was identified by the yeast two-hybrid and pull-down assays. These results suggest that the PfAG5 gene is involved in modulating early flowering in P. fugax.

Health-related quality of life assessed by Gout Impact Scale (GIS) in Chinese patients with gout.

OBJECTIVE: The Gout Impact Scale (GIS) is a disease-specific health-related quality of life (HR-QoL) measurement for patients with gout. This study aimed to investigate the quality of life in Chinese patients with gout and potential risk factors for poorer HR-QoL by GIS. METHODS: Adults with gout from February 2017 to February 2019 were invited to complete a questionnaire containing the GIS, social demographic characteristics, clinical information and gout-specific questions. Pearson/Spearman correlation and linear regression were used to analyze the data. RESULTS: A total of 413 patients were included in the analysis (mean age, 51.85 years; 96.4% male). The mean (SD) score of GIS total was 56.79 ± 15.45. Worse gout-specific HR-QoL was associated with anxiety (p < .05), depression (p < .05) and fatigue (p < .05). The effectiveness and global satisfaction of Treatment Satisfaction Questionnaire for Medication (TSQM) were negatively related to each dimension of GIS. Age (B = -0.251, p = .013), fatigue (B = 1.850, p < .001) and depression (B = 9.068, p = .042) were independent predictors of GIS total score. CONCLUSION: Gout-specific HR-QoL is impaired by social demographic and clinical characteristics, highlighting the importance of psychological factors (fatigue and depression) and patient-reported outcomes (patients' satisfaction and confidence in gout treatment). These findings suggest that more studies should focus on disease-specific HR-QoL.

Chelicerata sDscam isoforms combine homophilic specificities to define unique cell recognition.

Thousands of Down syndrome cell adhesion molecule (Dscam1) isoforms and ∼60 clustered protocadhrein (cPcdh) proteins are required for establishing neural circuits in insects and vertebrates, respectively. The strict homophilic specificity exhibited by these proteins has been extensively studied and is thought to be critical for their function in neuronal self-avoidance. In contrast, significantly less is known about the Dscam1-related family of ∼100 shortened Dscam (sDscam) proteins in Chelicerata. We report that Chelicerata sDscamα and some sDscamß protein trans interactions are strictly homophilic, and that the trans interaction is meditated via the first Ig domain through an antiparallel interface. Additionally, different sDscam isoforms interact promiscuously in cis via membrane proximate fibronectin-type III domains. We report that cell-cell interactions depend on the combined identity of all sDscam isoforms expressed. A single mismatched sDscam isoform can interfere with the interactions of cells that otherwise express an identical set of isoforms. Thus, our data support a model by which sDscam association in cis and trans generates a vast repertoire of combinatorial homophilic recognition specificities. We propose that in Chelicerata, sDscam combinatorial specificity is sufficient to provide each neuron with a unique identity for self-nonself discrimination. Surprisingly, while sDscams are related to Drosophila Dscam1, our results mirror the findings reported for the structurally unrelated vertebrate cPcdh. Thus, our findings suggest a remarkable example of convergent evolution for the process of neuronal self-avoidance and provide insight into the basic principles and evolution of metazoan self-avoidance and self-nonself discrimination.

StMADS11 Subfamily Gene PfMADS16 From Polypogon fugax Regulates Early Flowering and Seed Development.

The evolution of herbicide resistance in weedy plants leads to various adaptation traits including flowering time and seed germination. In our previous studies, we found an association of the early flowering phenotype with the ACCase inhibitor herbicide resistance genotype in a population of Polypogon fugax. MADS-box transcription factors are known to play pivotal roles in regulating plant flowering time. In this study, a SHORT VEGETATIVE PHASE (SVP)-like gene, belonging to the StMADS11 subfamily in the MADS-box family, was cloned from the early flowering P. fugax population (referred to as PfMADS16) and resistant to the herbicide clodinafop- propargyl. Overexpression of the SVP-like gene PfMADS16 in Arabidopsis thaliana resulted in early flowering and seed abortion. This is consistent with the phenotypic characters of resistant P. fugax plants, but contrary to the conventional role of SVP-like genes that usually suppress flowering. In addition, down regulation of the seed formation gene AtKTN1 in flowers of PfMADS16 transgenic Arabidopsis plants indicates that PfMADS16 may be indirectly associated with seed viability. Furthermore, one protein (PfMADS2) from the APETALA1 (AP1) subfamily interacting with PfMADS16 in P. fugax was identified with relevance to flowering time regulation. These results suggest that the PfMADS16 gene is an early flowering regulation gene associated with seed formation and viability in resistant P. fugax population. Our study provides potential application of PfMADS16 for integrated weed management (such as genetic-based weed control strategies) aiming to reduce the soil weed seedbank.

Changes in soil organic carbon and its influencing factors in the growth of Pinus sylvestris var. mongolica plantation in Horqin Sandy Land, Northeast China.

The change of soil organic carbon and its influencing factors after afforestation in sandy land should be taken into account. Here, the factors would be revealed which would influence the SOC dynamics to a depth of 100 cm during the development of Mongolian pine plantations in Horqin sandy land, northeast China. The chronosequence method was used to quantify the change of SOC in vertical distribution and influencing factors following conversion grassland to Pinus sylvestris var. mongolica forest in semi-arid sandy land, northeast China. Then the traditional statistical approaches were used to assessed the influence of the identified factors. Stand age played a major role in SOC dynamics. It took 38 years for SOC in 0-10 cm layer to recover to its initial level after afforestation, and 46 years for 10-20 cm layer. SOC accumulation increased with the age of Mongolian pine plantation. Over-mature forest fully embodied the advantage of SOC accumulation. In addition, the changes of SOC in 0-10 cm layer were also affected by TN, TP, TK and soil moisture, and those below 10 cm soil layers were related to the effects of TN, TP, TK, BD and CS.

Impact of climate factors on height growth of Pinus sylvestris var. mongolica.

Tree height growth is sensitive to climate change; therefore, incorporating climate factors into tree height prediction models can improve our understanding of this relationship and provide a scientific basis for plantation management under climate change conditions. Mongolian pine (Pinus sylvestris var. mongolica) is one of the most important afforestation species in Three-North Regions in China. Yet our knowledge on the relationship between height growth and climate for Mongolian pine is limited. Based on survey data for the dominant height of Mongolian pine and climate data from meteorological station, a mixed-effects Chapman-Richards model (including climate factors and random parameters) was used to study the effects of climate factors on the height growth of Mongolian pine in Zhanggutai sandy land, Northeast China. The results showed that precipitation had a delayed effect on the tree height growth. Generally, tree heights increased with increasing mean temperature in May and precipitation from October to April and decreased with increasing precipitation in the previous growing season. The model could effectively predict the dominant height growth of Mongolian pine under varying climate, which could help in further understanding the relationship between climate and height growth of Mongolian pine in semiarid areas of China.

Synthesis of sulfonated chitosan and its antibiofilm formation activity against E. coli and S. aureus.

A sulfonated chitosan (SCS) was prepared via nucleophilic substitution and characterized by Fourier transform infrared spectroscopy, 1H and 13C NMR spectra, gel permeation chromatography, elemental analysis, and thermo gravimetric analysis. The inhibition activities of bacterial adhesion and biofilm formation against E. coli and S. aureus of SCS were assessed in comparison with those of unmodified chitosan hydrochloride (WCS) which was commercially available. The metabolic activity and secretion of exopolysaccharide in biofilms of E. coli and S. aureus were significantly decreased after the treatment of SCS. Scanning electron microscopy and confocal laser scanning microscopy also demonstrated that SCS and WCS at 1MIC concentrations could obviously inhibit the formation of biofilm. Upon the experimental data obtained, it can be concluded that the alkylsulfonation of chitosan could significantly improve efficacy in killing biofilm-embedded bacteria, and the inhibition activities against biofilm formation of E. coli and S. aureus. The exploitation of SCS in this study is helpful to extend the understanding to an alternative to antibiotics and chemical preservatives in food and medicine fields.

Transcriptomics analysis of the flowering regulatory genes involved in the herbicide resistance of Asia minor bluegrass (Polypogon fugax).

BACKGROUND: Asia minor bluegrass (Polypogon fugax, P. fugax), a weed that is both distributed across China and associated with winter crops, has evolved resistance to acetyl-CoA carboxylase (ACCase) herbicides, but the resistance mechanism remains unclear. The goal of this study was to analyze the transcriptome between resistant and sensitive populations of P. fugax at the flowering stage. RESULTS: Populations resistant and susceptible to clodinafop-propargyl showed distinct transcriptome profiles. A total of 206,041 unigenes were identified; 165,901 unique sequences were annotated using BLASTX alignment databases. Among them, 5904 unigenes were classified into 58 transcription factor families. Nine families were related to the regulation of plant growth and development and to stress responses. Twelve unigenes were differentially expressed between the clodinafop-propargyl-sensitive and clodinafop-propargyl-resistant populations at the early flowering stage; among those unigenes, three belonged to the ABI3VP1, BHLH, and GRAS families, while the remaining nine belonged to the MADS family. Compared with the clodinafop-propargyl-sensitive plants, the resistant plants exhibited different expression pattern of these 12 unigenes. CONCLUSION: This study identified differentially expressed unigenes related to ACCase-resistant P. fugax and thus provides a genomic resource for understanding the molecular basis of early flowering.

Resistance of American sloughgrass (Bechmannia syzigachne) populations to ACCase-inhibiting herbicides involves three different target site mutations from China.

American sloughgrass [Beckmannia syzigachne (Steud.) Fernald] is a problematic annual grass weed in winter wheat fields of China, which causes great loss of wheat yield. Repeated use of acetyl-CoA carboxylase (ACCase)-inhibiting herbicides during the last two decades to control this weed has been selected for resistance in American sloughgrass in Jiangsu province. In this study, whole-plant dose-response assays were conducted to investigate the level of resistance in four resistant American sloughgrass populations (LY, JH, BYJ and BYP) to four ACCase-inhibiting herbicides belonging to aryloxyphenoxypropionates, cyclohexanediones, and phenylpyrazolines groups under greenhouse conditions. Based on resistance factor (RF), three populations, LY, BYJ and BYP, were highly resistant to fenoxaprop-P-ethyl, clodinafop propargyl, sethoxydim and pinoxaden. JH plants exhibited resistance to fenoxaprop-P-ethyl and clodinafop propargyl, but showed much lower RF values for sethoxydim and pinoxaden. Molecular analysis of resistance revealed that resistance in all the four populations was target site-based. Results confirmed that substitutions of Ile-1781-Leu, Ile-2041-Asn and Asp-2078-Gly, respectively, in LY, JH and BYJ/BYP, are responsible for diverse sensitivity to different ACCase-inhibiting herbicides in these populations. The substitution at position 1781 had been reported, while it is the first report of Ile-2041-Asn and Asp-2078-Gly mutations that corresponded to resistance in American sloughgrass.