Different Degrees Of Resistance Research Articles

Detection of Uropathogenic Specific Protein Gene (usp) and Multidrug Resistant Bacteria (MDR) of Pathogenic Escherichia coli Isolated from Baghdad City

Escherichia coli is gram negative bacteria and represents a typical resident of the digestive systems of both humans and animals. The stability and equilibrium of the luminal microbial flora are significantly influenced by E. coli. The Escherichia coli uropathogenic-specific protein (Usp) represents type of genotoxins produced by uropathogenic E. coli rather than fecal E. coli isolates. In the current study E. coli was isolated from urine and stool and usp gene was detected in it. Sensitivity test was evaluated by using different types of antibiotics and the usp gene was detected by PCR in all bacterial isolates. Antibiotics sensitivity test showed variable degrees of sensitivity and resistance. High percentage of sensitivity was achieved against amikacin (86%) and that for ciprofloxacin, ceftazidime, gentamicin and tobramycin it was 80%. Whereas trimethoprim and aztreonam showed 64% and 60% sensitivity respectively. In this study, most isolates were resistant to amoxicillin 92%; while they showed different degrees of resistance against other types of antibiotics (from tetracycline 62% to amikacin 4%). The frequency of multi drug resistant (MDR) bacteria was about 64 % (32 isolates), 30 from urine and 2 from the stool. The results showed that usp gene was found in 26 bacterial isolates (52%), whereas other 24 (48%) isolates didn’t have this gene. It was concluded that source of bacterial isolates carry usp gene was urine, with the exception of one isolate from f stool, and E. coli recorded as multidrug resistant bacteria (MDR).

Phytopathological screening of common winter wheat lines for resistance to Puccinia triticina

Abstract. Leaf rust on wheat caused by P. triticina is the most widespread fungal disease worldwide and in Bulgaria. The development of wheat genotypes resistant to leaf rust is related to the different types of resistance and ways of gene inheritance. The different varieties have different susceptibility during the different stages of their ontogenetic development. The study of the initial material is an important step in the breeding for resistance and it is an ongoing process. Two hundred and forty-six breeding lines were tested against the local population of P. triticina during 2015-2017, under conditions of infection field and in a greenhouse at Dobrudzha Agricultural Institute – General Toshevo, Bulgaria. Twenty lines were selected, which demonstrated different degrees of resistance under infection field conditions and which showed resistance to some of the seven pathotypes used in the study. The identification of the pathotypes was based on the type of reaction of 20 monogenic lines. The reaction of isogenic lines was compared with the reaction of the selection lines and the results showed that the reaction of line 165/05-46 corresponded to isogenic lines carrying genes Lr 9, Lr 19 and Lr 25. The response of the other 3 lines (245/03-72, 13/04-97, 14/06-110) partially coincided with the response of the above mentioned genes. The reaction of the other 3 lines (169/05-69, 14/06-81, 8/08-25) partially coincided with the reaction of isogenic lines carrying genes Lr 2a, Lr 28 and Lr 29. It was determined that seven of the lines were carriers of a race-specific gene and that it was necessary to subject these lines to further breeding and genetic studies to determine presence of race-specific resistance. Five of the lines (72/05-53, 61/03-75, 106/04-189, 268/03-151, 79/04-131) combined incomplete resistance at young stage with resistance at adult stage. Four of the tested lines (68/06-78, 29/02-133-38, 79/04-125-28, 197/05-33) exhibited typical race non-specific resistance or APR. Four lines (13/04-165, 14/05-119, 19/06-79 and 61/03-81) demonstrated “slow rusting” type of resistance. Twenty of the studied lines were carriers of effective resistance and can be included in the breeding programs as donors of resistance to P. triticina.

Antibiotic resistance of conditionally pathogenic Enterobacteriaceae strains causing acute diarrhoea diseases

Acute diarrheal disease presents a major public health problem, and the identification of pathogens serves both to identify the sources of spread of infections and to establish the correct treatment. In this context, the aim of this research was to detect the conditionally pathogenic agents from the Enterobacteriaceae family, which cause more frequently acute diarrheal diseases, and to test their sensitivity to antibiotics. The research was carried out during 2019–2022 within the Public Health Medical Institution TMA Buiucani, mun. Chișinău. 537 strains were isolated and eight conditionally pathogenic agents from the Enterobacteriaceae family were identified. During the study period, a slow decrease in the values of the quantitative indices of the conditional pathogenic agents was observed, the etiological spectrum was dominated by Klebsiella spp. (43,58 %). Conditionally pathogenic agents have registered a different degree of resistance to antibiotics, which underlines the importance of an antibiogram for the effectiveness of the therapy. A very high resistance was recorded to the penicillin. The results obtained during the study period reveal the importance of monitoring the antibiotic resistance, which is very significant in the treatment of acute diarrheal diseases.

Biodegradation of used engine oil by lead-resistant bacteria Acinetobacter sp.HAR20 newly isolated from harbour seawater (Oran, Algeria)

ABSTRACT This paper focuses on the degrading capacity of various hydrocarbon fractions of used engine oils (UEO) by marine microorganisms, as well as the biosorption of heavy metals. A bacterial strain with a significant capability to grow on UEO as a sole source of carbon and energy was isolated from harbour seawater samples (Oran, Algeria). The molecular identification by sequencing the 16S rDNA gene revealed that the bacterium matched Acinetobacter baumanii with 96.84% homology similarity. Thus, strain HAR20 was named Acinetobacter sp.HAR20. The degradation rate of UEO (at 1%, v/v) obtained after 15 days of incubation was about 53.4 ± 4.2%. The results of GC-MS analysis of the biodegraded residual motor oil indicate that strain Acinetobacter sp.HAR20 degrades alkanes with chain lengths ranging from C4 to C48 completely or to shorter fractions. The bacterium was also able to degrade all aromatic compounds of UEO, including polycyclic aromatic hydrocarbons (alkylated and no alkylated naphthalene, alkylated phenanthrene, and fluorene). The strain Acinetobacter sp.HAR20 exhibited different degrees of resistance to the heavy metals tested (Cd, Zn, Ni, Cu, Fe, and Pb). The highest tolerance was obtained for Pb (600 mg.l−1). The study of lead biosorption at a concentration of 300 mg.l−1 revealed that the bacterium displayed a removal rate of 57.47 ± 7.5%. The strain Acinetobacter sp.HAR20 has shown an interesting biodegradation potential; therefore, it could be proposed as a choice for the bioremediation of contaminated seawater by used engine oils.

Physiological response of Phlox paniculata L. varieties to different growing conditions of Western Siberia

Physiological indicators of plants are essential characteristics of plant adaptation to adverse environmental factors. Phlox paniculata varieties (originated from North America) introduced into the southern taiga subzone of Western Siberia experience stress caused by numerous factors. The physiological response to different growing conditions of the southern taiga subzone of Western Siberia was analyzed for 3 varieties of Ph. paniculata. The study employed handheld optical instruments for vital analysis of plant physiological parameters: a compact LI-600P porometer (LI-COR) and a CI-710 leaf spectrometer (CID Bio-Science). Stomatal conductance of phlox leaves in partial shade studied with respect to different varieties was found to virtually remain unchanged. The studied varieties exhibit different degree of resistance to water deficiency. The variety ‘Stanislas’ was found to be resistant to insufficient soil humidity and light, it can be grown in both moderately shaded areas and arid conditions. The studied varieties showed high indices of anthocyanins and carotenoids under good light conditions and natural humidity, which indicates these conditions as the most stressful for Ph. paniculata due to a high degree of water and temperature stress. The greatest difference in the measured indices was found for the variety ‘Antarktida’, which indicates its susceptibility to water deficiency.

Impaired efficacy of fenbendazole and ivermectin against intestinal nematodes in adult horses in Iran

This study aimed to evaluate the efficacy of fenbendazole and ivermectin on strongyles and Parascaris sp. infecting adult riding horses in three regions with different climates. During 2021 and 2022 fecal specimens were randomly collected from 483 horses older than three years in 31 equestrian clubs in Hamedan (n = 217), Yazd (n = 146) and Tabriz cities (n = 120). Eggs were counted by McMaster technique, and the strongyle larvae were identified using coproculture, PCR and sequencing. Horses with strongyles and Parascaris egg counts ≥150 were enrolled in fecal egg count reduction (FECR) examination following treatment with ivermectin or fenbendazole. In total, 26.5% of examined horses were positive with at least one parasite. Infection rates varied in three cities i.e., 25.8% in Hamedan, 28.8% in Yazd, 25% in Tabriz. Fifty-seven horses had FECR measured. FECR below <90% was observed for IVM-strongyle in two horses in Tabriz, for FBZ-strongyle in two horses in Tabriz and two horses in Hamedan, for IVM-Parascaris in one horse in all three cities, and for FBZ-Parascaris in one horse in Yazd. Furthermore, FECR 90–100% was observed in IVM-Parascaris and FBZ -Parascaris groups in Tabriz. Data herein presented demonstrate different degrees of resistance of strongyles and Parascaris infecting horses in Iran against both ivermectin and fenbendazole. Since non-principled use of anthelminthics is common among horse owners, urgency of test-and-treatment strategy should be educated and implemented by policy-making organizations. Evaluating efficacy of different anthelminthics and choosing the most effective treatment in each region is suggested.

Seedling and adult plant resistance to leaf rust in some Bulgarian common wheat lines.

The response of 250 common winter wheat breeding lines was investigated for resistance to the causative agent of Puccinia triticina under conditions of an infected field on the territory of Dobrudzha Agricultural Institute - General Toshevo, Bulgaria, during three successive seasons. Twenty lines with different degrees of resistance under field conditions were selected. Multi-pathotype testing was used to study the response of these lines at seedling stage under greenhouse conditions to individual pathotypes of P. triticina. Based on the response of the lines at seedling and adult stages, we found out that 20 % of them carried race-specific resistance. One of the lines (99/08-52) reacted with full resistance to the pathotypes used under greenhouse conditions. The reaction demonstrated by this line coincided with the response of isogenic lines carrying the genes Lr9, Lr19, Lr22a, Lr22b and Lr25. The other three lines (19/06- 108, 82/08-43 and 82/08-35) showed a resistant reaction to 6 or 5 of the pathotypes used in the study. Their response partially coincided with the reaction of 5 isogenic lines, and the presence of some of these genes in the above lines is quite possible. Lines carrying this type of resistance are to be subjected to further genetic and breeding investigations to prove the presence of a race-specific gene. Twenty-five percent of the lines combined partial race-specific resistance at seedling stage with the resistance of race non-specific nature at adult stage. Forty percent of all studied lines carried race non-specific resistance, and 15 % of the lines possessed resistance of the "slow rusting" type. As a result of the study we carried out, the lines that demonstrated stable resistance to leaf rust can provide sufficient protection of the host and can be included in the breeding programs for developing varieties resistant to P. triticina.

Double sodium channel mutation, I265T/L1014F, is possibly related to pyrethroid-resistant in Thrips palmi.

Thrips palmi Karny (Thysanoptera: Thripidae) can harm a variety of agricultural crops and transmit plant viruses, causing heavy economic losses. In the Hainan province of China, pyrethroids were sprayed widely to control T. palmi, which leaded to resistance to pyrethroids in T. palmi. The bioassay has shown that the resistance ratio of T. palmi to pyrethroids increases annually. Resistance ratio to λ-cyhalothrin has increased from 10.711 to 23.321 and to cypermethrin has increased from 5.507 to 23.051 for 3 years, 2020-2022. The double mutation (I265T/L1014F) was identified from the field strain for the first time, which were located in the domains I and II of the voltage-gated sodium channel of T. palmi, respectively. The double mutation is probably the reason for the higher resistance of T. palmi in Hainan. The frequencies of the double mutation were 53.33% in HN2020, 70.00% in HN2021, and 96.67% in HN2022. Results indicated that T. palmi had developed different degrees of resistance to pyrethroids in Hainan. This study provides theoretical guidance for the use of insecticides in the field control of thrips.

Identification, expression profiles and involvement in insecticides tolerance and detoxification of carboxylesterase genes in Bactrocera dorsalis

Carboxylesterases (CarEs) are a multifunctional superfamily of enzymes and play an important role in detoxification of various insecticides in insects. The oriental fruit fly, Bactrocera dorsalis, is one of the most destructive agricultural pests and has developed different degrees of resistance to organophosphates in field. However, the involvement of BdCarEs in tolerance or resistance to other alternative insecticides are still unclear. In the present study, 33 BdCarEs genes were identified based on the genome database of B. dorsalis. Phylogenetic analysis demonstrated that they were classified into nine clades, with abundance of α-esterases. Meanwhile, the sequence characterization and the chromosome distribution were also analyzed. The spatiotemporal expression analysis of BdCarEs genes suggested that the diversity of potential function in different physiological processes. With the exception of BdCarE21, all BdCarEs genes responded to at least one insecticide exposure, and BdCarE20 was found to be up-regulated after exposure to all five tested insecticides individually. Eight BdCarEs genes were overexpressed in MR strain when compared to that in SS strain. Subsequently, knockdown the expression of representative BdCarEs genes significantly increased the susceptibility of the oriental fruit fly to corresponding insecticides, which indicated that the tested BdCarEs genes contributed to one or multiple insecticide detoxification. These findings provide valuable insights into the potential role in respond to tolerance or resistance to insecticides with different mode of action, and will facilitate development of efficiency management strategy for B. dorsalis.

ПОРІВНЯЛЬНА ХАРАКТЕРИСТИКА ФУНКЦІОНАЛЬНОГО СТАНУ ОРГАНІЗМУ СТУДЕНТОК ПЕРШОГО РОКУ НАВЧАННЯ ІЗ РІЗНИМ ТИПОМ ГЕМОДИНАМІКИ

Differences in the regulatory effects of cardiovascular mechanisms and heart rate variability in female students of the first year of study are considered in this article. A lot of changes occur in the social sphere and in the psychophysiological state of the students' bodies after admission to the higher educational school. Adaptive processes are multi-level and are accompanied by stress on body systems. The most striking functional changes in the body are manifested in changes in the state and functions of the cardiovascular system. The circulatory system is one of the first to be involved in the formation of adaptive reactions under the reflex-regulatory control of the ANS. Individuals with different types of blood circulation are characterized by different adaptation possibilities and different degrees of resistance to the action of extreme influences. The conditions of educational activity in the specialty at the university will be an extreme factor for students of the first year.&#x0D; In order to evaluate central hemodynamic parameters, height and body weight indicators, heart rate (HR), systolic blood pressure (BPs), diastolic blood pressure (BPd) were obtained at rest. Based on them, the following are calculated: pulse blood pressure (BP), systolic blood volume (SBV), minute blood volume (MBV), body surface area (S), cardiac index (CI). The regulatory effects of ANS were determined by heart rate indicators. Cardio intervals were registered and recorded for 5 minutes. Indicators of vegetative homeostasis were calculated according to the formulas of Baevsky R.M.&#x0D; According to CI indicators, the subject contingent was divided into groups according to the type of hemodynamics: eukinetic (n=70) and hyperkinetic (n=53).&#x0D; The obtained results showed the absence of significant differences in body weight and growth indicators between groups (p ≥ 0.05).&#x0D; The differences between groups were in indicators of central hemodynamics and heart rhythm. It was established that in students with a eukinetic type of central hemodynamics, adaptation to the conditions of a higher educational institution was ensured by optimal adaptive mechanisms - low HR, SBV, MBV and HVR. This indicates the economy in the work of the circulatory system and the predominance of parasympathetic regulation. In students with a hyperkinetic type high HR and SBV, MBV, HVR were recorded (p ≤ 0.05), which indicated an increase in the work of the circulatory system and the activity of the sympathetic branch of the ANS.&#x0D; These indicators in both groups were within the normal range, but in the group with the hyperkinetic type they approached the upper limit (p ≤ 0.05). This indicated an increase in the stress on the regulatory mechanisms in maintaining vegetative homeostasis and the stress on the body's functional reserves of students of this group.

An Alternative Method to Evaluate Resistance to Pear Scab (Venturia nashicola).

Two pear cultivars with different degrees of resistance to Venturia nashicola were evaluated on the basis of a disease severity rating for pear scab resistance under controlled environmental condition. Two inoculation techniques were tested: the procedure for inoculation by dropping conidia suspension of V. nashicola; the procedure by deposition of agar plug on the abaxial surface of pear leaves. All tested cultivars resulted in blight symptoms on the inoculated leaves and became spread to uninoculated region or other leaves. Although both methods provide satisfactory infection of V. nashicola on pear leaves, the mycelial plug method of inoculation was more reliable than the spray inoculation method for the evaluation of pear scab disease resistance. The incubation period of V. nashicola in the resistant pear cultivar, Greensis was longer than that in the susceptible cultivar, Hwasan.

Insecticide resistance monitoring and diagnostics of resistance mechanisms in cotton‐melon aphid, Aphis gossypii Glover in Central China

AbstractAphis gossypii Glover is one of the most serious pests in China, and the management of this pest mainly relies on insecticides. However, the resistance status of A. gossypii in Central China is still unknown. Therefore, in this study, we firstly determined the susceptibility of 15 A. gossypii field populations from Central China to six chemical insecticides using leaf‐dipping method during 2020 and 2021 and explored the potential resistance mechanisms of these populations. Most of the field populations of A. gossypii have evolved low to high levels of resistance to imidacloprid (RR = 5.98–2352.96‐fold), thiamethoxam (RR = 5.98–2194.96‐fold), flonicamid (RR = 7.18–306.07‐fold), and pirimicarb (RR = 6.90–283.00‐fold); however, 13 tested field populations remained susceptible to chlorpyrifos. For λ‐cyhalothrin, most populations have evolved low to moderate levels of resistance (RR = 5.72–47.38‐fold). The results of correlation analysis indicated that there was a prominent positive correlation between the enzyme activity of cytochrome P450 and the logarithm of LC50 to thiamethoxam and pirimicarb. Carboxylesterase (CarE) was positively correlated with λ‐cyhalothrin, while glutathione S‐transferase (GST) was negatively correlated with λ‐cyhalothrin. Furthermore, we found that multiple resistance associated target site mutations (V62I, R81T, A302S, S431F, M918L) can be detected in the field populations of A. gossypii. Aphis gossypii in Central China have developed different degrees of resistance to tested insecticides and enhanced detoxification of cytochrome P450 and carboxylesterase and co‐existed resistance mutations contribute to the multiple resistance of these field populations. Our results provide valuable information about the status of insecticide resistance in China and are helpful for designing sustainable management strategies of A. gossypii.

Transcriptome and metabolome reveal the role of flavonoids in poplar resistance to poplar anthracnose

Poplar anthracnose, caused mainly by Colletotrichum gloeosporioides, is one of the most important diseases occurring in poplar plantations in China, and it causes serious economic and ecological losses every year. Different poplar crosses and species have different degrees of resistance to poplar anthracnose; Populus × canadensis is resistant, P. tomentosa is susceptible, and P. × beijingensis exhibits intermediate resistance. To investigate the reasons for differences in resistance to poplar anthracnose, we performed metabolomic and transcriptomic analyses of these three poplars. Metabolomic analyses showed that, after C. gloeosporioides infection, 117, 112, and 52 secondary metabolites accumulated in P. × canadensis, P. × beijingensis, and P. tomentosa, respectively; of which 31, 27, and seven, respectively, were flavonoids. The total flavonoids content was higher in P. × canadensis and P. × beijingensis than in P. tomentosa. Transcriptomics analyses showed that, after infection with C. gloeosporioides, the transcript levels of most flavonoid biosynthesis genes were highest in P. × canadensis, followed by P. × beijingensis, and lowest in P. tomentosa. These results were verified by qRT-PCR. Therefore, we speculate that the degree of anthracnose resistance in poplar is related to the types and contents of flavonoids and the transcript levels of genes in the flavonoid biosynthesis pathway. This information will be useful for devising new strategies to control poplar anthracnose and to breed new, resistant poplar materials.

Molecular identification of glutathione S‐transferase genes and their potential roles in insecticides susceptibility of Grapholita molesta

AbstractGrapholita molesta is one kind of serious fruit‐boring pests in the world, which caused huge economic losses to the fruit industry including pear and apple. The heavy usage of synthetic insecticides resulted in different degrees of resistance of G. molesta to some commonly used insecticides. However, the tolerance mechanisms of G. molesta to insecticides are still unclear. Glutathione S‐transferases (GSTs) belong to the superfamily of detoxifying enzymes and mainly play important roles in detoxification metabolism and insecticide susceptibility of insects. In this study, we first evaluated the toxicity of three insecticides including emamectin benzoate, chlorantraniliprole and lambda‐cyhalothrin on G. molesta at different developmental stages. Synergism study showed that the susceptibility of G. molesta larvae to these three insecticides obviously increased when the enzyme activity of GST was inhibited by diethyl maleate compared with the controls. Next, we screened out six GmGST genes which are upregulated after insecticides treatment from a total of 21 GmGST genes and analysed their sequence characteristics and expression profiles. RNAi and bioassay results further revealed that the mortality of 5th instar larvae significantly increased after exposure to LC30 of emamectin benzoate, chlorantraniliprole and lambda‐cyhalothrin when silencing of GmGSTo2, GmGSTs1 and GmGSTz1 compared with the controls. In conclusion, this study indicated that GmGSTo2, GmGSTs1 and GmGSTz1 play important roles in insecticides susceptibility of G. molesta to three commonly used insecticides, which is significance for its future integrated management.

Response to drift kelp is modified by both substratum and season: green sea urchin foraging behaviour in subsidized habitats

The ability of organisms to detect, locate and navigate to resource patches is modified by the surrounding landscape. Green sea urchinsStrongylocentrotus droebachiensisin barren grounds exist in a food-limited state and are subject to intense competition. Rapid detection and consumption of resource patches, particularly pieces of macroalgae from adjacent algal beds, are key in determining individual growth, survival and reproductive success. Detection and movement to resource patches requires moving through a heterogeneous benthic seascape composed of rocky and sandy patches, presenting different degrees of resistance to movement. We used time-lapse photography to describe the foraging behaviour of urchins in relation to the presence of a key resource subsidy (drift kelp) and different benthic seascapes. We demonstrated that urchins could detect the presence of drift kelp in barren-ground habitats and alter their movement behaviour in response, but did not exhibit the ability to directionally navigate towards kelp in field conditions. Seascapes with increased proportions of rocky substrata facilitated increased movement in response to the presence of drift. Moreover, urchin foraging behaviour was temporally variable, with no response to the presence of drift in early spring (May). This indicates not only that interpretations of observations of urchin behaviour must take intrinsic and extrinsic seasonal dynamics into account, but that extrapolating results to explain larger-scale patterns and processes must include both spatially explicit subtidal seascapes and temporal dynamics. In many temperate and boreal regions, this indicates the need for increased subtidal benthic research in the fall and winter.

A transcriptome analysis of Benincasa hispida revealed the pathways and genes involved in response to Phytophthora melonis infection.

Wilt disease caused by Phytophthora melonis infection is one of the most serious threats to Benincasa hispida production. However, the mechanism of the response of B. hispida to a P. melonis infection remains largely unknown. In the present study, two B. hispida cultivars with different degrees of resistance to P. melonis were identified: B488 (a moderately resistant cultivar) and B214 (a moderately susceptible cultivar). RNA-seq was performed on P. melonis-infected B488 and B214 12 hours post infection (hpi). Compared with the control, 680 and 988 DEGs were respectively detected in B488 and B214. A KEGG pathway analysis combined with a cluster analysis revealed that phenylpropanoid biosynthesis, plant-pathogen interaction, the MAPK signaling pathway-plant, and plant hormone signal transduction were the most relevant pathways during the response of both B488 and B214 to P. melonis infection, as well as the differentially expressed genes in the two cultivars. In addition, a cluster analysis of transcription factor genes in DEGs identified four genes upregulated in B488 but not in B214 at 6 hpi and 12 hpi, which was confirmed by qRT-PCR. These were candidate genes for elucidating the mechanism of the B. hispida response to P. melonis infection and laying the foundation for the improvement of B. hispida.

Osmotic stress resistance of different sorghum species affected by NaСl

Introduction. One of the most urgent issue of plant production which attracts the attention of many researchers and farmers, is salt tolerance of plants. Salinity has a negative effect, caused by the disruption of an osmotic balance of a cell that negatively affects water regime of plants. At the same time, plants experience growth inhibition and reduce their yield.The purpose of the study was to estimate resistance of different sorghum species to chloride salinity and to identify the most resistant genotypes.Methods. The study was carried out in the laboratory for plant physiology in 2018–2021. For the current study there has been carries out a modelling of a salt stress by a pure salt solution (concentration of 13 atm.) according to a conventional methodology, the control was distilled water.Results. There has been established the salinity stress effect on seed germination of different sorghum species. The values of germination energy and laboratory germination of grain sorghum were 53.1% and 62.0%; of sweet sorghum — 39.1% and 43.1; the values of Sudan grass — 30.1 and 33.5%, respectively. In the first and second groups — of highly resistant and resistant species (seed germination affected by salinity ranged from 61 to 100%) — were are 61% of grain sorghum genotypes, 56% of sugar sorghum genotypes and 6% of Sudan grass genotypes. There has been established a resistance degree and identified some features of the development of varieties with different degrees of resistance to this stress (length of sprouts and primary roots). Grain sorghum was found less susceptible to salinity stress of all studied species. Among grain sorghum samples, 9 genotypes have demonstrated the highest salinity resistance with a germination rate from 87.5 (Uch. 22/20) to 95.9% (Uch. 29/20). The maximum values were shown by the samples of Uch. 29/20 (95.95%), Uch. 20/20 (93.9%), Uch. 21/20 (93.8%), Jetta x Uch. 45/20 (91.5%) and Uch. 7/20 (90.8%), which indicated the ability to tolerate severe salinity concentration.

Resilience of ecosystem service delivery in grasslands in response to single and compound extreme weather events

Extreme weather events are increasing in frequency and magnitude with profound effects on ecosystem functioning. Further, there is now a greater likelihood that multiple extreme events are occurring within a single year. Here we investigated the effect of a single drought, flood or compound (flood + drought) extreme event on temperate grassland ecosystem processes in a field experiment. To assess system resistance and resilience, we studied changes in a wide range of above- and below-ground indicators (plant diversity and productivity, greenhouse gas emissions, soil chemical, physical and biological metrics) during the 8 week stress events and then for 2 years post-stress. We hypothesized that agricultural grasslands would have different degrees of resistance and resilience to flood and drought stress. We also investigated two alternative hypotheses that the combined flood + drought treatment would either, (A) promote ecosystem resilience through more rapid recovery of soil moisture conditions or (B) exacerbate the impact of the single flood or drought event. Our results showed that flooding had a much greater effect than drought on ecosystem processes and that the grassland was more resistant and resilient to drought than to flood. The immediate impact of flooding on all indicators was negative, especially for those related to production, and climate and water regulation. Flooding stress caused pronounced and persistent shifts in soil microbial and plant communities with large implications for nutrient cycling and long-term ecosystem function. The compound flood + drought treatment failed to show a more severe impact than the single extreme events. Rather, there was an indication of quicker recovery of soil and microbial parameters suggesting greater resilience in line with hypothesis (A). This study clearly reveals that contrasting extreme weather events differentially affect grassland ecosystem function but that concurrent events of a contrasting nature may promote ecosystem resilience to future stress.

Review of predatory mites as biocontrol agents against thrips in China

Thrips are one of the most destructive pests of vegetables, fruits, and ornamental crops worldwide (Wan et al., 2020; Davari et al., 2021). The more severe species include Frankliniella occidentalis, Frankliniella intonsa, Thrips tabaci, Thrips flavidulus, Pseudodendrotrips mori, Scirtothrips dorsalis, and Megalurothrips usitatus (You et al., 2007; Zheng et al., 2007; Saito et al., 2022). Many thrips have developed resistance to pesticides. For example, Frankliniella occidentalis developed different degrees of resistance to organochlorine, organophosphorus, carbamate, and pyrethroid insecticides and environmentally friendly insecticides (Broadbent and Pree, 1997; Sun et al., 2022). Tobacco thrips have developed resistance to pyrethroid and organic phosphate insecticides (Krob et al., 2022). Soybean thrips also developed varying degrees of resistance to emamectin benzoate, beta-cypermethrin, and imidacloprid (Tang et al., 2016). Therefore, searching and screening effective natural enemies for biological control of thrips is urgent.&#x0D;

In Silico Study of the Acquired Resistance Caused by the Secondary Mutations of KRAS G12C Protein Using Long Time Molecular Dynamics Simulation and Markov State Model Analysis.

Kirsten rat sarcoma viral oncogene homolog (KRAS) is a small GTPase protein which plays an important role in the treatment of KRAS mutant cancers. The FDA-approved AMG510 and MRTX849 (phase III clinical trials) are two potent KRASG12C-selective inhibitors that target KRAS G12C. However, the drug resistance caused by the second-site mutation in KRAS has emerged, and the mechanisms of drug resistance at atom level are still unclear. To clarify the mechanisms of drug resistance, we conducted long time molecular dynamics simulations (75 μs in total) to study the structural and energetic features of KRAS G12C and its four drug resistant variants to inhibitors. The combined binding free energy calculation and protein-ligand interaction fingerprint revealed that these second-site mutations indeed caused KRAS to produce different degrees of resistance to AMG510 and MRTX849. Furthermore, Markov State Models and 2D-free energy landscapes analysis revealed the difference in conformational changes of mutated KRAS bound with and without inhibitors. Furthermore, the comparative analysis of these systems showed that there were differences in their allosteric signal pathways. These findings provide the molecular mechanism of drug resistance, which helps to guide novel KRAS G12C inhibitor design to overcome drug resistance.