Multiple herbicide resistance in a Cyperus difformis population in rice field from China.

Herbicide resistance is rapidly emerging in Cyperus difformis in rice fields across China. The response of a C. difformis population GX-35 was tested against five acetolactate synthase (ALS)-inhibiting herbicides, auxin herbicide MCPA and photosynthesis II (PSII)-inhibitor bentazone. Population GX-35 evolved multiple resistance to ALS-inhibiting herbicides (penoxsulam, bispyribac­sodium, pyrazosulfuron-ethyl, halosulfuron-methly and imazapic) and auxin herbicide MCPA, with resistance levels of 140-, 1253-, 578-, 18-, 13-, and 21-fold, respectively, compared to the susceptible population. In this population, ALS gene expression was similar to that of the susceptible population. However, an Asp376Glu mutation in ALS gene was observed, leading to reduced inhibition of in-vitro ALS activities by five ALS-inhibiting herbicides. Furthermore, CYP71D8, CYP77A3, CYP78A5 and three ABC transporter genes (cluster-14412.23067, cluster-14412.25321, and cluster-14412.24716) over-expressed in absence of penoxsulam. On the other hand, an UGT73C1 and an ABC transporter (cluster-14412.25038) were induced by penoxsulam. Additionally, both over-expression and induction were observed for CYP74, CYP71A1, UGT88A1 and an ABC transporter (cluster-14412.21723). The GX-35 population has indeed evolved multiple herbicide resistance in China. Therefore, a diverse range of weed control tactics should be implemented in rice field.

Correction: Chen et al. Evolution of Microstructure in Welding Heat-Affected Zone of G115 Steel with the Different Content of Boron. Materials 2022, 15, 2053.

In the original publication [...].

Quantitative analysis of three ingredients in Salvia miltiorrhiza by near infrared spectroscopy combined with hybrid variable selection strategy.

Rosmarinic acid (RA), Tanshinone IIA (Tan IIA), and Salvianolic acid B (Sal B) are crucial compounds found in Salvia miltiorrhiza. Quickly predicting these components can aid in ensuring the quality of S. miltiorrhiza. Spectral preprocessing and variable selection are essential processes in quantitative analysis using near infrared spectroscopy (NIR). A novel hybrid variable selection approach utilizing iVISSA was employed in this study to enhance the quantitative measurement of RA, Tan IIA, and Sal B contents in S. miltiorrhiza. The spectra underwent 108 preprocessing approaches, with the optimal method being determined as orthogonal signal correction (OSC). iVISSA was utilized to identify the intervals (feature bands) that were most pertinent to the target chemical. Various methods such as bootstrapping soft shrinkage (BOSS), competitive adaptive reweighted sampling (CARS), genetic algorithm (GA), variable combination population analysis (VCPA), successive projections algorithm (SPA), iteratively variable subset optimization (IVSO), and iteratively retained informative variables (IRIV) were used to identify significant feature variables. PLSR models were created for comparison using the given variables. The results fully demonstrated that iVISSA-SPA calibration model had the best comprehensive performance for Tan IIA, and iVISSA-BOSS had the best comprehensive performance for RA and Sal B, and correlation coefficients of cross-validation (R2cv), root mean square errors of cross-validation (RMSECV), correlation coefficients of prediction (R2p), and root mean square errors of prediction (RMSEP) were 0.9970, 0.0054, 0.9990 and 0.0033, 0.9992, 0.0016, 0.9961 and 0.0034, 0.9998, 0.0138, 0.9875 and 0.1090, respectively. The results suggest that NIR spectroscopy, along with PLSR and a hybrid variable selection method using iVISSA, can be a valuable tool for quickly quantifying RA, Sal B, and Tan IIA in S. miltiorrhiza.

Impact of pyroxasulfone on sugarcane rhizosphere microbiome and functioning during field degradation.

Pyroxasulfone (PYR) is a widely used herbicide, but its effects on non-target organisms, particularly microorganisms, are largely unknown. Herein, we investigated the effects of various doses of PYR on the sugarcane rhizosphere microbiome by using amplicon sequencing of rRNA genes and quantitative PCR techniques. Correlation analyses indicated that several bacterial phyla (Verrucomicrobia and Rhodothermaeota) and genera (Streptomyces and Ignavibacteria) strongly responded to PYR application. Additionally, we found that both bacterial diversity and composition were significantly altered after 30 days, indicating a prolonged effect of the herbicide. Moreover, co-occurrence analyses of the bacterial community showed that the network complexity was significantly decreased by PYR at day 45. Furthermore, FAPROTAX analysis suggested that some functions with implications for carbon cycling groups were significantly altered after 30 days. Overall, we provide the first indications that PYR may not pose a significant risk for altering microbial communities in the short term (less than 30 days). However, its potential negative effects on bacterial communities in the middle and late stages of degradation deserve further attention. To our knowledge, this is the first study to provide insight into the effects of PYR on the rhizosphere microbiome, providing an extended basis for future risk assessments.

Evolution of Microstructure in Welding Heat-Affected Zone of G115 Steel with the Different Content of Boron.

Welding thermal simulation was performed to investigate the effects of boron content (0, 60, and 130 ppm), welding peak temperature (Tp), and cooling time from 800 to 500 °C (t8/5) on the microstructure, carbide, subgrain, and microhardness of heat-affected zone (HAZ) in G115 steel. According to the experimental results, the microstructure of coarse-grained HAZ (CGHAZ), fine-grained HAZ (FGHAZ), inter-critical HAZ (ICHAZ), and sub-critically HAZ (SCHAZ) was martensite, martensite containing a small amount of undissolved carbide, martensite, and over-tempered martensite, tempered martensite, respectively. The presence of B element improved the thermal stability of M23C6 carbide, thereby resulting in a greater amount of undissolved carbides with a larger diameter in the materials with higher B content under the same Tp. Element B is effective in improving Ac1 and Ac3 for the material. Besides, compared with the material without and containing 60 ppm B, the Ac1 and Ac3 of the material containing 130 ppm B increased by 95 and 108 °C, 69 and 77 °C, respectively. Meanwhile, the FGHAZ area of the material containing 130 ppm B was significantly lower than the material without or containing 60 ppm B, indicating that element B can significantly reduce the formation range of FGHAZ. The alloy content in austenite of ICHAZ of materials without or containing 60 ppm B increased, compared with CGHAZ, its Ms and Mf declined by 50 and 7 °C, 46 and 7 °C, respectively. In contrast, the alloy content in austenite of the material with 130 ppm B content decreases, its Ms and Mf was 37 °C and 32 °C higher than CGHAZ, respectively. The microhardness of HAZ was ranked in descending order as CGHAZ, FGHAZ, ICHAZ, and SCHAZ. Differently, the microhardness of CGHAZ and FGHAZ showed an increasing trend with the rise of B content but exhibited a decreasing trend with the rise of t8/5.

Characterization and genomic analysis of a bensulfuron methyl-degrading endophytic bacterium Proteus sp. CD3 isolated from barnyard grass (Echinochloa crus-galli).

Bensulfuron methyl (BSM) is a widely used sulfonylurea herbicide in agriculture. However, the large-scale BSM application causes severe environmental problems. Biodegradation is an important way to remove BSM residue. In this study, an endophytic bacterium strain CD3, newly isolated from barnyard grass (Echinochloa crus-galli), could effectively degrade BSM in mineral salt medium. The strain CD3 was identified as Proteus sp. based on the phenotypic features, physiological biochemical characteristics, and 16S rRNA gene sequence. The suitable conditions for BSM degradation by this strain were 20-40°C, pH 6-8, the initial concertation of 12.5-200 mg L-1 with 10 g L-1 glucose as additional carbon source. The endophyte was capable of degrading above 98% BSM within 7 d under the optimal degrading conditions. Furthermore, strain CD3 could also effectively degrade other sulfonylurea herbicides including nicosulfuron, halosulfuron methyl, pyrazosulfuron, and ethoxysulfuron. Extracellular enzyme played a critical role on the BSM degradation by strain CD3. Two degrading metabolites were detected and identified by using liquid chromatography-mass spectrometry (LC-MS). The biochemical degradation pathways of BSM by this endophyte were proposed. The genomic analysis of strain CD3 revealed the presence of putative hydrolase or esterase genes involved in BSM degradation, suggesting that a novel degradation enzyme for BSM was present in this BSM-degrading Proteus sp. CD3. The results of this research suggested that strain CD3 may have potential for using in the bioremediation of BSM-contaminated environment.

Crystal orientation and crystal structure of paramagnetic α-Al under a pulsed electromagnetic field.

The intermittent electromagnetic fields with a large [Formula: see text] can enhance the properties of ferromagnetic materials and significantly affect paramagnetic materials. In this study, the effect of a pulsed electromagnetic field on the crystal orientation of the primary phase and microstructure evolution of an Al-Zn-Mg-Cu alloy was investigated. A mathematical model was developed to describe crystal rotation under a pulsed electromagnetic field. The model predictions show that the magnetic energy difference generated by the magnetic anisotropy of the primary crystal produces primary phases with sizes of 225-100 µm to rotate into a <111> preferred orientation. The lattice constant, the interplanar spacing, and the microstrain increase with the duty cycle of the pulsed magnetic field, especially for the (111) and (200) crystal planes. This study provides preliminary theoretical support for using pulsed electromagnetic fields to control the orientation and microscopic properties of materials.