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Torenia fournieri L. is a popular ornamental plant in the genus Torenia, widely used in commercial landscaping, especially during the summer. Additionally, Torenia has served as a model ornamental plant in many studies exploring ornamental characteristics and pest control through genetic engineering. To date, no research has been reported on developing insect-resistant Torenia expressing genes from Bacillus thuringiensis (Bt). In this study, a recombinant vector carrying the Cry1Ab gene from Bt, pBI121-Cry1Ab, was constructed and transferred into T. fournieri via Agrobacterium tumefaciens-mediated transformation. A total of 13 shoots survived on the kanamycin selection medium, among which four putative transgenic lines, designated L1, L2, L7, and L11, were molecularly confirmed by PCR and Southern blot analysis, indicating successful integration of the Cry1Ab gene into the genomes of these lines. Quantitative real-time PCR and ELISA results further verified the successful expression of the Cry1Ab gene in the leaves of all four transgenic lines. Insect bioassay results demonstrated that all four transgenic lines showed strong resistance to the insect pest, Mythimna separata, with mortality rates ranging from 59.9% to 100.0%, in contrast to a larval mortality rate of 16.2% in the wild-type Torenia. Additionally, these transgenic lines significantly decreased in larval survival rates compared to those fed on wild-type plants. Furthermore, these transgenic lines activated superoxide dismutase (SOD) activity at 12 and 24 h, and catalase (CAT) activity at 72 h, while suppressing SOD activity at 72 h, and peroxidase (POD) activity over time. Our findings indicate that these transgenic lines exhibit high resistance to the insect pest and provide new insights into controlling insect pests in ornamental plants through genetic approaches. [ABSTRACT FROM AUTHOR]

Under the stress of biological (aphid) and abiotic factors (drought), whether the application of wood vinegar compound biological agents can increase crop resistance and achieve stable crop production is of great significance for coping with the challenges brought by future climate change to agricultural production. In this study, drought and wood vinegar were used as treatment factors, and the "Glycine max-Aphis Glycines-Harmonia Axyridis" three-level nutrition system was used as the research object, with a total of 18 treatments. Soybean biomass, root-shoot ratio, population dynamics of A.glycines, predation of H.axyridis, developmental duration, and activities of glutathione-S-transferase (GST) and catalase (CAT) in soybean, A.glycines and H. axyridis were measured. The main results are as follows: (1) Under mild and severe drought stress, soybean biomass (-29.6%, -66.6%) decreased significantly, and root shoot ratio (15.2%, 37.5%) increased significantly. When there were only aphids (lack of natural enemies), spraying wood vinegar liquid phase under mild drought stress significantly increased the biomass of soybean in the group without wood vinegar (16.2%). Under mild drought, the GST activity of soybean increased significantly (117.5%), and the GST (46.5%) and CAT (13.3%) activities of soybean increased significantly after spraying wood vinegar. However, the activities of GST (-78.0%), POD (-63.9%) and CAT (-81.4%) were significantly decreased under severe drought stress. (2) The population of A.glycines (-12.9%, -22.1%) decreased significantly under mild and severe drought stress. Under mild drought stress and severe drought stress, the application of wood vinegar liquid phase significantly reduced the population of soybean aphids without wood vinegar (-16.9%, -20.0%) . The activities of GST (149.6%) and CAT (48.3%) were significantly increased under severe drought stress. Under mild drought stress, the activities of GST (77.8%) and CAT (52.4%) of A. glycines sprayed with wood vinegar increased significantly. (3) Under severe drought stress, the daily predation of H.axyridis adults decreased significantly (-16.6%), and the daily predation of H.axyridis adults increased significantly after the application of wood vinegar (8.7%). The developmental duration of H.axyridis larvae under mild drought and severe drought stress was significantly longer than that under normal watering group (4.9%, 10.9%). The developmental duration (-4.2%, -5.3%) of H.axyridis larvae fed with wood vinegar treatment under mild drought and wood vinegar treatment under severe drought was significantly shortened. The activities of GST (43.2%) and CAT (156.5%) of H. axyridis were significantly increased under severe drought stress. Therefore, drought stress will inhibit the growth and development of soybean, while spraying wood vinegar can promote the growth and development of soybean, improve the drought resistance of soybean, and have a positive effect on the direct control of soybean aphids and the improvement of the control effect of natural enemies on A.glycines. [ABSTRACT FROM AUTHOR]

[Aim] To measure changes in the activity of protective and detoxifying enzymes in the F0 and the F1 generations of the 3rd instar of Riptortus pedestris nymphs exposed to different concentrations of thiamethoxam. [Methods] Reniform soybean seeds soaked in water were immersed in 25% thiamethoxam WG that had been diluted with different amounts of water to obtain LC10 (5.2 mg/L), LC20 (11.2 mg/L), LC30 (19.6 mg/L), LC40 (31.6 mg/L) and LC50 (49.4 mg/L) solutions. Water was the control. F0 nymphs of R. pedestris were fed the treated seeds for 24 hours after which changes in the activity of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE), glutathione S-transferase (GST) and carboxylesterase (CarE) in surviving nymphs was measured. Another group of nymphs was placed in cages and fed soybean seeds treated with water until F1 generation nymphs had developed to the 3rd instar, after which changes in the activity of POD, CAT, SOD, AChE, GST, and CarE were determined in vivo. [Results] After treatment with different concentrations of thiamethoxam, the POD, CAT, SOD, GST and CarE activity of F0 generation nymphs was higher than that of the control group. POD, AChE, GST and CarE activity of F1 larvae were also higher than that of the control group. The POD, GST and CarE activity of F1 larvae was higher than those of F0 larvae for all treatment concentrations. AChE enzyme activity of F1 larvae was higher than that of F0 larvae for concentrations in the range of LC20-LC50. Protective and detoxifying enzyme activity in F0 and F1 larvae was positively correlated with thiamethoxam concentration. [Conclusion] F0 R. pedestris nymphs detoxify thiamethoxam by increasing their POD, CAT, SOD, GST and CarE enzyme activity, whereas F1 nymphs detoxify thiamethoxam by increasing their POD, AChE, GST and CarE activity. The observed changes in POD, AChE, GST and CarE enzyme activity may be the mechanism responsible for pesticide resistance in R. pedestris F1 nymphs. [ABSTRACT FROM AUTHOR]

We made separate experiments to examine life‐history traits and activities of protective enzymes as affected by carbon dioxide (CO2) elevation to 780 μL/L as compared to 390 μL/L in imidacloprid‐ or buprofezin‐resistant strains of the brown planthopper (BPH) Nilaparvata lugens. We found an interaction effect between resistance and the CO2 level on the nymphal survival and duration in both resistant strains. Nymphal durations in both resistant strains were much shorter in the resistant than susceptible BPH at 780 μL/L but similar between them or slightly shorter in the resistant than susceptible BPH at 390 μL/L. Nymphal survival was lower for imidacloprid‐resistant than its susceptible BPH at 390 μL/L but higher at 780 μL/L; it stayed unaffected by the CO2 elevation in buprofezin‐resistant BPH. We did not observe an interaction effect between resistance and the CO2 level on major reproductive parameters in both resistant strains. But the 2 strains were not consistent across CO2 levels in all parameters. Our measurements of protective enzyme activities of superoxide dismutase, catalase, and peroxidase showed an interaction between resistance and the CO2 level. Overall, these enzymes became similar in activity between resistant and susceptible BPH at 780 μL/L compared to 390 μL/L and the change was more distinct in the imidacloprid‐ than buprofezin‐resistant BPH strains. Our findings suggest that CO2 elevation can affect life‐history traits of insecticide‐resistant BPH, while the effect may vary depending on the kind of insecticides it is resistant to. [ABSTRACT FROM AUTHOR]

Morphological attributes and chemical composition of host plants shape growth and development of phytophagous insects via influences on their behavior and physiological processes. This research delves into the relationship between Eriogyna pyretorum and various host plants through studuying how feeding on different host tree species affect growth, development, and physiological enzyme activities. We examined E. pyretorum response to three distinct host plants: Camphora officinarum, Liquidambar formosana and Pterocarya stenoptera. Notably, larvae feeding on C. officinarum and L. formosana displayed accelerated development, increased pupal length, and higher survival rates compared to those on P. stenoptera. This underlines the pivotal role of host plant selection in shaping the E. pyretorum's life cycle. The activities of a-amylase, lipase and protective enzymes were the highest in larvae fed on the most suitable host L. formosana which indicated that the increase of these enzyme activities was closely related to growth and development. Furthermore, our investigation revealed a relationship between enzymatic activities and host plants. Digestive enzymes, protective enzymes, and detoxifying enzymes exhibited substantial variations contingent upon the ingested host plant. Moreover, the total phenolics content in the host plant leaves manifested a noteworthy positive correlation with catalase and lipase activities. In contrast, a marked negative correlation emerged with glutathione S-transferase and α-amylase activities. The total developmental duration of larvae exhibited a significant positive correlation with the activities of GST and CarE. The survival rate of larvae showed a significant positive correlation with CYP450. These observations underscore the insect's remarkable adaptability in orchestrating metabolic processes in accordance with available nutritional resources. This study highlights the interplay between E. pyretorum and its host plants, offering novel insights into how different vegetation types influence growth, development, and physiological responses. These findings contribute to a deeper comprehension of insect-plant interactions, with potential applications in pest management and ecological conservation. [ABSTRACT FROM AUTHOR]

Morphological attributes and chemical composition of host plants shape growth and development of phytophagous insects via influences on their behavior and physiological processes. This research delves into the relationship between Eriogyna pyretorum and various host plants through studuying how feeding on different host tree species affect growth, development, and physiological enzyme activities. We examined E. pyretorum response to three distinct host plants: Camphora officinarum, Liquidambar formosana and Pterocarya stenoptera. Notably, larvae feeding on C. officinarum and L. formosana displayed accelerated development, increased pupal length, and higher survival rates compared to those on P. stenoptera. This underlines the pivotal role of host plant selection in shaping the E. pyretorum’s life cycle. The activities of a-amylase, lipase and protective enzymes were the highest in larvae fed on the most suitable host L. formosana which indicated that the increase of these enzyme activities was closely related to growth and development. Furthermore, our investigation revealed a relationship between enzymatic activities and host plants. Digestive enzymes, protective enzymes, and detoxifying enzymes exhibited substantial variations contingent upon the ingested host plant. Moreover, the total phenolics content in the host plant leaves manifested a noteworthy positive correlation with catalase and lipase activities. In contrast, a marked negative correlation emerged with glutathione S-transferase and α-amylase activities. The total developmental duration of larvae exhibited a significant positive correlation with the activities of GST and CarE. The survival rate of larvae showed a significant positive correlation with CYP450. These observations underscore the insect’s remarkable adaptability in orchestrating metabolic processes in accordance with available nutritional resources. This study highlights the interplay between E. pyretorum and its host plants, offering novel insights into how different vegetation types influence growth, development, and physiological responses. These findings contribute to a deeper comprehension of insect-plant interactions, with potential applications in pest management and ecological conservation.

Torenia fournieri L. is a popular ornamental plant in the genus Torenia, widely used in commercial landscaping, especially during the summer. Additionally, Torenia has served as a model ornamental plant in many studies exploring ornamental characteristics and pest control through genetic engineering. To date, no research has been reported on developing insect-resistant Torenia expressing genes from Bacillus thuringiensis (Bt). In this study, a recombinant vector carrying the Cry1Ab gene from Bt, pBI121-Cry1Ab, was constructed and transferred into T. fournieri via Agrobacterium tumefaciens-mediated transformation. A total of 13 shoots survived on the kanamycin selection medium, among which four putative transgenic lines, designated L1, L2, L7, and L11, were molecularly confirmed by PCR and Southern blot analysis, indicating successful integration of the Cry1Ab gene into the genomes of these lines. Quantitative real-time PCR and ELISA results further verified the successful expression of the Cry1Ab gene in the leaves of all four transgenic lines. Insect bioassay results demonstrated that all four transgenic lines showed strong resistance to the insect pest, Mythimna separata, with mortality rates ranging from 59.9% to 100.0%, in contrast to a larval mortality rate of 16.2% in the wild-type Torenia. Additionally, these transgenic lines significantly decreased in larval survival rates compared to those fed on wild-type plants. Furthermore, these transgenic lines activated superoxide dismutase (SOD) activity at 12 and 24 h, and catalase (CAT) activity at 72 h, while suppressing SOD activity at 72 h, and peroxidase (POD) activity over time. Our findings indicate that these transgenic lines exhibit high resistance to the insect pest and provide new insights into controlling insect pests in ornamental plants through genetic approaches.

The artificial environment control experiment was conducted at Nanjing University of Information Science and Technology from November to December 2022 using strawberry "Selva" (Fragaria ananassa) as the test material, and the strawberry seedlings were selected and placed in the artificial climate chamber for low-temperature treatment in mid-November when they reached the flowering stage. Three levels of temperature were set: 5°C (daily minimum)/15°C (daily maximum), 10°C/20°C and 15°C/25°C (CK). The treatment duration was 3d, 6d and 9d. The kinetic parameters of photosystem fluorescence induction and protease activity of strawberry leaves were measured under different days of low-temperature to understand the effect of low-temperature on photosystem fluorescence and protease activity of strawberry leaves. The effects of low-temperature on the fluorescence properties of strawberry leaves and the activity of protease were measured. The results showed that (1) the light energy absorbed per reaction center (ABS/RC), the energy dissipated per reaction center (DIo/RC) and the energy captured per reaction center for QA reduction (TRo/RC) of strawberry leaves increased with decreasing temperature and increasing duration in the range of daily minimum temperature from 5°C to 15 °C, but the energy captured per reaction center for QA reduction (ETo/RC) increased with increasing duration. The energy captured per reaction center for electron transfer (ETo/RC) decreased. ABS/RC and DIo/RC were 1.367 and 1.718 times higher than those of CK for the treatment with daily minimum temperature of 5°C for 9d, respectively. TRo/RC increased by 7.42%, 14.66%, 25.27%, and 30.48% for daily minimum temperature of 10°C for 3d, 6d, 9d and daily minimum temperature of 5°C for 9d, respectively, compared to CK, while ETo/RC decreased by 1.71%, 20.39%, 26.65%, and 28.32%, respectively, compared to CK. The quantum ratio for thermal dissipation (φDo) increased significantly with the duration of low-temperature, 12.34% and 25.32% higher than CK at a daily minimum temperature of 5 C for 3d and 9d, respectively. However, the quantum yield for electron transfer (φEo) decreased with the prolongation of low-temperature, and decreased by 27.92% and 43.02% compared with CK for 3d and 9d, respectively. (2) The activities of superoxide dismutase (SOD),catalase (CAT), peroxidase (POD), and malondialdehyde (MDA) of strawberry leaves gradually increased with the decrease of temperature and the extension of the duration of low-temperature. The activities of SOD and POD reached the maximum at the daily minimum temperature of 5C for 6d, which were 1.39 and 2.03 times higher than those of CK, respectively, while CAT was less affected by low temperature. The MDA content was the highest at the minimum daily temperature of 5°C for 9d, which was 2.10 times higher than that of CK. The study showed that low temperatures will damage the structure and function of the photosystem of strawberry leaves, the photochemical efficiency decreases, the energy dissipated by heat increases, resulting in a decrease in the ability of PS II donor side to provide electrons, and the electron transfer efficiency decreases, strawberry leaves will stimulate the antioxidant system in the body, and produce a certain resistance to the environment, which shows that the activities of SOD, POD and CAT have different degrees of increase compared with CK. However, the cell membrane structure was still damaged and the membrane permeability increased. [ABSTRACT FROM AUTHOR]

In recent years, severe hailstorms have caused damage to cotton leaves and stalks. In order to identify the effects of cotton leaf damage on its dry matter accumulation, protective enzyme activity and yield in different periods, in this experiment, different intensities of hail were simulated by manual leaf cutting. In this study, the effects of leaf damage on dry matter accumulation, chlorophyll fluorescence, POD (peroxidase), SOD (superoxide dismutase) and MDA levels (malondialdehyde), and yield of cotton were studied in field experiments at three stages (bud, full bud and flower boll stages) and in sub-plots with different artificial defoliation intensities (0%, 25%, 50%, 75% and 100%). Removing the leaf sources had differently sized effects on the "sink" at each stage, and these are ordered as follows: flowering and boll stage > full bud stage > pregnancy stage. The greater the intensity of leaf removal, the greater the impact on the "sink". Among them, after removing 50% of the leaves at the full bud stage, the total dry matter of the cotton plant increased by 12.46% compared to that of the control, and the boll formation rate per plant increased by 14.99%, resulting in overcompensation. Mo, Vj and φDo all showed a tendency to decrease and then increase with the increase in defoliation intensity at different periods of the treatment, and the lowest values of Mo, Vj and φDo, and the largest values of φpo, ψo and φEo were found in the 50% defoliation treatment at the gestational bud stage. The values of ψo and φEo were at the maximum in the 25% defoliation treatment at the full bud stage. The values of Mo and Vj in the different defoliation treatments at the bolling stage showed a tendency to increase and then decrease with the increase in defoliation intensity, with the highest values in the 25% treatment and the smallest values of φpo, ψo and φEo in the 25% defoliation treatment. The POD enzyme activity level was elevated in the defoliation treatments at the three different periods, and the highest value was observed in the 50% defoliation group at the full bud and boll stages, which is a reflection of supercompensation. The SOD enzyme activity level tended to increase with the intensity of defoliation, and defoliation at the gestational and full bud stages first enhanced and then weakened the stress on the cotton plants. The differences between treatments decreased after 12 weeks. The stress of defoliation on cotton plants was weakened at the boll stage. With the increase in defoliation intensity, the content of MDA showed a gradual increasing trend. The cotton MDA content was higher than that of the other treatments at 75% defoliation at both the post-fertilized bud and full bud stage. [ABSTRACT FROM AUTHOR]

Fritillaria taipaiensis P. Y. Li is a widely used medicinal herb in treating pulmonary diseases. In recent years, its wild resources have become scarce, and the demand for efficient artificial cultivation has significantly increased. This article is the first to apply phosphate solubilizing bacteria isolated from the rhizosphere soil of F. taipaiensis P. Y. Li to the cultivation process of F. taipaiensis P. Y. Li. The aim is to identify suitable reference strains for the artificial cultivation and industrial development of F. taipaiensis P. Y. Li by examining the effects of various phosphate solubilizing bacteria and their combinations on photosynthesis, physiological and biochemical properties, and gene expression related to the protective enzyme system in F. taipaiensis P. Y. Li. The experiment, conducted in pots at room temperature, included a control group (CK) and groups inoculated with inorganic phosphorussolubilizing bacteria: W1 (Bacillus cereus), W2 (Serratia plymuthica), W12 (Bacillus cereus and Serratia plymuthica), and groups inoculated with organophosphorus-solubilizing bacteria: Y1 (Bacillus cereus), Y2 (Bacillus cereus), Y12 (Bacillus cereus and Bacillus cereus), totaling seven groups. Compared to CK, most growth indices in the bacterial addition groups showed significant differences, with W12 achieving the highest values in all indices except the leaf area index. The content of photosynthetic pigments, photosynthetic parameters, and osmoregulatory substances increased variably in each bacterial treatment group. W12 exhibited the highest content of chlorophyll a and soluble protein, while W1 had the highest free proline content. The activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) in all inoculated groups were higher than in CK, with significant changes in SOD and CAT activities. The malondialdehyde (MDA) content in all inoculated groups was lower than in CK, with Y12 being the lowest, at approximately 30% of CK. Gene expression corresponding to these three enzymes also increased variably, with POD expression in Y2 being the highest at 2.73 times that of CK. SOD and CAT expression in Y12 were the highest, at 1.84 and 4.39 times that of CK, respectively. These results indicate that inoculating phosphate solubilizing bacteria can enhance the growth of F. taipaiensis P. Y. Li, with the mixed inoculation groups W12 and Y12 demonstrating superior effects. This lays a theoretical foundation for selecting bacterial fertilizers in the cultivation process of F. taipaiensis P. Y. Li. [ABSTRACT FROM AUTHOR]

There is a long history to cultivate the Pogostemon cablin in Guangdong Province, and it is a famous medicinal material. The bacterial wilt is the important disease that impacts the production and quality of P. cablin. Aiming to the control effects of metabolites of Alternaria sp. GHX-P17 strain that is belonging to an endophytic fungus isolated from the stems and leaves of P. cablin and the mechanism of disease resistance on bacterial wilt, a laboratory experiment had been conducted to investigate the incidence and severity of bacterial wilt in P. cablin at different time after artificial to inoculate the strain of Alternaria sp. GHX-P17 and to spray the crude extracts of the metabolites, and disease index (DI) was calculated. The activity changes of protective enzymes of phenylalanine ammonia lyase (PAL), peroxidase (POD）and superoxide dismutase (SOD) were determined in different time in P. cablin. The results were as follows: (1) The DI was significantly lower in the treatment groups with the crude extracts of Alternaria sp. GHX-P17 at different concentrations than that of control groups, and the DI decreased by 27.16% in the treatment groups at 204 h after inoculation. The variance analysis showed significant differences (P

The green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), is an economically devastating crop pest worldwide. The M. persicae (SEF-R) population of a cabbage field in China was tested for susceptibilities to 13 insecticides. Compared with the susceptible population (FFJ-S), extremely high and high resistance to beta-cypermethrin (324-fold) and imidacloprid (106.9-fold) was detected in SEF-R. More importantly, this is the first report of resistance in the field M. persicae population to sulfoxaflor (32.4-fold), flupyradifurone (9.5-fold), pymetrozine (34.8-fold), spirotetramat (8.1-fold), flonicamid (5.8-fold), and broflanilide (15.8-fold) in China when compared with FFJ-S. The resistance factor decayed to a low level to sulfoxaflor and pymetrozine after 15 generations without any selection pressure. The resistance-related mutations (R81T and kdr) detected in SEF indicated target-site resistance to neonicotinoids and pyrethroids, respectively. Biochemical assays revealed the involvement of monooxygenase, carboxylesterase, superoxide dismutase, and peroxidase in a multi-insecticide resistance mechanism. The overexpression of P450s, esterases, and a UDP-glycosyltransferase might be responsible for the multi-insecticide resistance in SEF-R. The knockdown of CYP6CY3 in SEF-R increased its susceptibility to imidacloprid, thiacloprid, and thiamethoxam, which verified that P450s play vital roles in neonicotinoid metabolism. Our findings provide guidance for the rational use of insecticides to delay resistance development in GPA. [ABSTRACT FROM AUTHOR]

Solanum nigrum L. is an invasive weed in Xinjiang cotton fields, and an important factor affecting cotton quality and reducing cotton yield. Pendimethalin is the most commonly used pre-emergence herbicide on cotton. However, the status of S. nigrum resistance to pendimethalin and the physiological and biochemical mechanisms remain poorly understood. In this study, we investigated how S. nigrum regulates nutrient accumulation, protective enzyme activity, and metabolic enzyme activity in the body to resist injury following pendimethalin exposure. The results showed that the resistant BL‑1 population developed a higher level of resistance to pendimethalin than the sensitive SHZ‑8 population, with a resistance index of 26.20. After pendimethalin treatment, the activity of cytochrome P450 and glutathione S‑transferase enzymes was significantly higher in the resistant biotype than in the sensitive biotype, with peak values of 0.27 U L−1 and 0.22 U L−1 on day 25, respectively. The malondialdehyde and soluble sugar content, and superoxide dismutase activity of both sensitive and resistant biotypes first increased than decreased, but there were no significant differences in peroxidase activity or soluble protein content. The results show that S. nigrum developed a high level of resistance to pendimethalin in Xinjiang cotton fields, and differences in glutathione S‑transferase and cytochrome P450 enzymes associated with pendimethalin metabolism might be related to resistance. [ABSTRACT FROM AUTHOR]

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Abstract Background 2-methyl-4-chlorophenoxy acetic acid-Na (MPCA-Na) is a phenoxy carboxylic acid selective hormone herbicide that is widely used in the crop fields. However, drift of MPCA-Na during application is highly damaging to cotton (Gossypium hirsutum) and other crop plants. This study was carried out from 2019 to 2020 to determine the effects of different concentrations of MPCA-Na on physiological and metabolic activities besides growth and yield of cotton plants at seedling, budding, flowering and boll stages. Moreover, we evaluated the different combinations of 24-epibrassinolide, gibberellin (GA3), phthalanilic acid and seaweed fertilizer to ameliorate herbicide damage. Results 2-methyl-4-chlorophenoxy acetic acid-Na (MPCA-Na) exposure caused a decrease in the chlorophyll content, and an increase in the soluble protein content, Malondialdehyde (MDA) content and protective enzyme activity. It also caused significant reductions in plant height, boll number and the single boll weight at the seedling and budding stages, but had little effects on plant height and the single boll weight at flowering and boll stage. Under the maximum recommended dose of MPCA-Na (130 g/L), the number of cotton bolls at seedling and budding stages decreased by 75.33 and 79.50%, respectively, and the single boll weight decreased by 46.42 and 36.31%, respectively. Nevertheless, the number of G. hirsutum bolls and single boll weight at flowering and boll stage decreased by 48.15 and 5.38%, respectively. Application of plant growth regulators decreased the MDA content, and increased chlorophyll, soluble protein content and protective enzyme activity, and alleviated MCPA-Na toxicity. Positive effects in case of growth regulators treated plants were also observed in terms of G. hirsutum yield. Phthalanilic acid + seaweed fertilizer, 24-epibrassinolide + seaweed fertilizer, and GA3 + seaweed fertilizer should be used at the seedling, budding, and flowering and boll stages, respectively. Conclusions The results of current study suggest that certain plant growth regulators could be used to alleviate MPCA-Na damage and maintain G. hirsutum yield. When the cotton exposed to MCPA-Na at the seedling stage, it should be treated with phthalanilic acid + seaweed fertilizer, while plants exposed at the budding stage should be treated with 24-epibrassinolide + seaweed fertilizer, and those exposed at the flowering and boll stages should be treated with GA3 + seaweed fertilizer to mitigate stress.

In order to explore the effects of antagonistic bacterium treatment on the preservation effect and protective enzyme activity of muskmelon, this study selected Xizhoumi 25 melon as the research object, and inoculated the melon surface with Bacillus velezensis BG-2 at 25 ℃ and 4 ℃. The colonization characteristics, preservation effect, peroxidase (POD), polyphenol oxidase (PPO) and phenylalnine ammonialyase (PAL) of antagonistic bacteria on melon surface during storage were determined. Under the conditions of 25 ℃ and 4 ℃, the number of antagonistic bacteria on melon surface increased firstly and then decreased. The fresh-keeping effect, pH and soluble solid content decreased of muskmelon inoculated with antagonistic bacteria were significantly better than those of control group. POD and PAL activities increased first and then decreased, PPO activity increased first and then decreased at room temperature, and slowly increased at 4 ℃. At 25 ℃, the enzyme activity of POD, PAL and PPO in antagonistic treatment group was the highest on the 20th day, and the highest on the 10th day. Under 4 ℃, POD and PAL activity were the highest on the 20th day. The highest enzyme activity on the 40th day of PPO treatment. The enzyme activity of the antagonistic bacterium treatment was always higher than pathogen treatment. Bacillus BG-2 could stably colony on the epidermal of muskmelon at both 25 ℃ and 4 ℃, inhibited the decaed of muskmelon during storage, delayed the decreased of pH, soluble solids content, POD, PPO and PAL enzyme activities, and the combinated of BG-2 and low temperature had better effect on the above. This study provided a theoretical basis for prolonged the storage period of Xinjiang muskmelon and provided technical support for the antagonistic bacterium effect of muskmelon after harvest.

In recent years, severe hailstorms have caused damage to cotton leaves and stalks. In order to identify the effects of cotton leaf damage on its dry matter accumulation, protective enzyme activity and yield in different periods, in this experiment, different intensities of hail were simulated by manual leaf cutting. In this study, the effects of leaf damage on dry matter accumulation, chlorophyll fluorescence, POD (peroxidase), SOD (superoxide dismutase) and MDA levels (malondialdehyde), and yield of cotton were studied in field experiments at three stages (bud, full bud and flower boll stages) and in sub-plots with different artificial defoliation intensities (0%, 25%, 50%, 75% and 100%). Removing the leaf sources had differently sized effects on the “sink” at each stage, and these are ordered as follows: flowering and boll stage > full bud stage > pregnancy stage. The greater the intensity of leaf removal, the greater the impact on the “sink”. Among them, after removing 50% of the leaves at the full bud stage, the total dry matter of the cotton plant increased by 12.46% compared to that of the control, and the boll formation rate per plant increased by 14.99%, resulting in overcompensation. Mo, Vj and φDo all showed a tendency to decrease and then increase with the increase in defoliation intensity at different periods of the treatment, and the lowest values of Mo, Vj and φDo, and the largest values of φpo, ψo and φEo were found in the 50% defoliation treatment at the gestational bud stage. The values of ψo and φEo were at the maximum in the 25% defoliation treatment at the full bud stage. The values of Mo and Vj in the different defoliation treatments at the bolling stage showed a tendency to increase and then decrease with the increase in defoliation intensity, with the highest values in the 25% treatment and the smallest values of φpo, ψo and φEo in the 25% defoliation treatment. The POD enzyme activity level was elevated in the defoliation treatments at the three different periods, and the highest value was observed in the 50% defoliation group at the full bud and boll stages, which is a reflection of supercompensation. The SOD enzyme activity level tended to increase with the intensity of defoliation, and defoliation at the gestational and full bud stages first enhanced and then weakened the stress on the cotton plants. The differences between treatments decreased after 12 weeks. The stress of defoliation on cotton plants was weakened at the boll stage. With the increase in defoliation intensity, the content of MDA showed a gradual increasing trend. The cotton MDA content was higher than that of the other treatments at 75% defoliation at both the post-fertilized bud and full bud stage.

Abstract Background Mepiquat chloride (DPC) enhances the resistance of cotton plants, and it is widely used as a growth regulator. DPC can stimulate photosynthesis, stabilize the structure of cotton leaves, and affect population reproduction and energy substances in Aphis gossypii Glover (cotton aphids), but interactions between DPC and cotton aphids remain unclear. In this study, we analyzed the physiological responses of cotton to DPC, and the toxicity of DPC toward cotton aphids, before and after feeding, to explore the DPC-induced defense mechanism against cotton aphids. Results Measurements of protective enzyme activity in cotton showed that the soluble protein contents, peroxidase (POD) activity, and catalase (CAT) activity in cotton treated with different concentrations of DPC were higher than in the control. Superoxide dismutase (SOD) activity was higher than that of the control when the concentration of DPC was

Hyphantria cunea is a globally distributed quarantine plant pest. In a previous study, the Cordyceps javanica strain BE01 with a strong pathogenic effect on H. cunea was identified, and overexpression of the subtilisin-like serine protease CJPRB of this strain was found to accelerate the death of H. cunea (previous research results). In this study, the active recombinant CJPRB protein was obtained through the Pichia pastoris expression system. It was found that CJPRB protein administration to H. cunea via infectation, feeding and injection was able to induce changes in protective enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and polyphenol oxidase (PPO), and the expression of immune defense-related genes in H. cunea. In particular, CJPRB protein injection induced a more rapid, widespread and intense immune response in H. cunea compared to the other two treatment methods. The results suggest that the CJPRB protein may play a role in eliciting a host immune response during infectation by C. javanica. [ABSTRACT FROM AUTHOR]

Background: 2-methyl-4-chlorophenoxy acetic acid-Na (MPCA-Na) is a phenoxy carboxylic acid selective hormone herbicide that is widely used in the crop fields. However, drift of MPCA-Na during application is highly damaging to cotton (Gossypium hirsutum) and other crop plants. This study was carried out from 2019 to 2020 to determine the effects of different concentrations of MPCA-Na on physiological and metabolic activities besides growth and yield of cotton plants at seedling, budding, flowering and boll stages. Moreover, we evaluated the different combinations of 24-epibrassinolide, gibberellin (GA3), phthalanilic acid and seaweed fertilizer to ameliorate herbicide damage. Results: 2-methyl-4-chlorophenoxy acetic acid-Na (MPCA-Na) exposure caused a decrease in the chlorophyll content, and an increase in the soluble protein content, Malondialdehyde (MDA) content and protective enzyme activity. It also caused significant reductions in plant height, boll number and the single boll weight at the seedling and budding stages, but had little effects on plant height and the single boll weight at flowering and boll stage. Under the maximum recommended dose of MPCA-Na (130 g/L), the number of cotton bolls at seedling and budding stages decreased by 75.33 and 79.50%, respectively, and the single boll weight decreased by 46.42 and 36.31%, respectively. Nevertheless, the number of G. hirsutum bolls and single boll weight at flowering and boll stage decreased by 48.15 and 5.38%, respectively. Application of plant growth regulators decreased the MDA content, and increased chlorophyll, soluble protein content and protective enzyme activity, and alleviated MCPA-Na toxicity. Positive effects in case of growth regulators treated plants were also observed in terms of G. hirsutum yield. Phthalanilic acid + seaweed fertilizer, 24-epibrassinolide + seaweed fertilizer, and GA3 + seaweed fertilizer should be used at the seedling, budding, and flowering and boll stages, respectively. Conclusions: The results of current study suggest that certain plant growth regulators could be used to alleviate MPCA-Na damage and maintain G. hirsutum yield. When the cotton exposed to MCPA-Na at the seedling stage, it should be treated with phthalanilic acid + seaweed fertilizer, while plants exposed at the budding stage should be treated with 24-epibrassinolide + seaweed fertilizer, and those exposed at the flowering and boll stages should be treated with GA3 + seaweed fertilizer to mitigate stress. [ABSTRACT FROM AUTHOR]

Subtropical China is projected to experience elevated temperature greater than the mean global temperature increase and is accompanied by reduced precipitation. The plasticity of roots to changing environment strongly influences ecosystem feedbacks to climate change. However, knowledge gaps on the individual and combined effects of warming and precipitation reduction on root systems hinder our ability to accurately predict the growth and adaptability of forests under future climate change. To examine the effects of warming (W) and precipitation reduction (P) on roots physiology and morphology of Chinese-fir saplings, we used a randomized complete block design with factorial soil warming (ambient, ambient + 5℃) and precipitation reduction (ambient, ambient-50 %) treatments. A full excavation method was adopted to obtain roots, then we measured the root physiology (osmoregulatory substances, oxidant substances, protective enzymes, endogenous hormones), morphology (specific root length, SRL; surface root area, SRA; root tissue density, RTD). The content of carbon and nitrogen, isotopes (δ13C and δ15N); soil temperature, soil moisture and sapling growth were also measured. We found that compared with the control, W decreased the abscisic acid (IAA) content; P increased the contents of hydrogen peroxide (H 2 O 2) and proline (Pro), and decreased the contents of IAA and cytokinin (CTK); warming plus precipitation reduction (WP) increased the Pro content, and decreased the contents of IAA and CTK. In addition, the effects of W and P on root morphology varied with soil depth and root diameter class. W, P, and WP all increased fine root SRL and SRA in deep soil. Warming and precipitation reduction could affect physiological traits (e.g. non-enzymatic substances and antioxidant enzymes) and subsequently morphological traits via influencing soil environment and root tissue chemistry. Collectively, the results indicated that Chinese-fir saplings responded to warming and precipitation reduction by comprehensive regulation of the non-enzymatic substances (e.g., osmotic substances and endogenous hormones) of fine roots and changing root morphological characteristics in deep soil. • Precipitation reduction (P) and warming plus P (WP) increased the proline content. • Warming (W) and WP decreased the abscisic acid (IAA) content. • P increased membrane lipid peroxidation but the damage was relatively mild. • The effect of W and P on root morphology varied with soil depth and diameter class. • W, P, and WP treatments increased SRL and SRA in deep soil. [ABSTRACT FROM AUTHOR]

Powdery mildew, caused by Sphaerotheca fuliginea (Schlecht.) Poll., and melon aphids (Aphis gossypii Glover) are a typical disease and insect pest, respectively, that affect cucumber production. Powdery mildew and melon aphid often occur together in greenhouse production, resulting in a reduction in cucumber yield. At present there are no reports on the physiological and biochemical effects of the combined disease and pest infection/infestation on cucumber. This study explored how cucumbers can regulate photosynthesis, protective enzyme activity, and basic metabolism to resist the fungal disease and aphids. After powdery mildew infection, the chlorophyll and free proline contents in cucumber leaves decreased, while the activities of POD (peroxidase) and SOD (superoxide dismutase) and the soluble protein and MDA (malondialdehyde) contents increased. Cucumber plants resist aphid attack by increasing the rates of photosynthesis and basal metabolism, and also by increasing the activities of protective enzymes. The combination of powdery mildew infection and aphid infestation reduced photosynthesis and basal metabolism in cucumber plants, although the activities of several protective enzymes increased. Aphid attack after powdery mildew infection or powdery mildew infection after aphid attack had the opposite effect on photosynthesis, protective enzyme activity, and basal metabolism regulation. Azoxystrobin and imidacloprid increased the contents of chlorophyll, free proline, and soluble protein, increased SOD activity, and decreased the MDA content in cucumber leaves. However, these compounds had the opposite effect on the soluble sugar content and POD and CAT (catalase) activities. The mixed ratio of the two single agents could improve the resistance of cucumber to the combined infection of powdery mildew and aphids. These results show that cucumber can enhance its pest/pathogen resistance by changing physiological metabolism when exposed to a complex infection system of pathogenic microorganisms and insect pests. [ABSTRACT FROM AUTHOR]

Four evergreen broadleaf Rhododendron spp. (Rhododendrons), namely, Rhododendron aganniphum, R. nyingchiense, R. wardii, and R. triflorum, occur in harsh subalpine habitats in the southwest Qinghai-Tibet Plateau (QTP), China. Considering that the four Rhododendrons cannot escape their unique environment, they must evolve a set of adaptations to survive, but the information is lacking. To uncover their physiological adaptation characteristics, in the present study, we monitored their physiological characteristics by determination of their seasonal variation in antioxidant enzyme activity, osmotic adjustment substrates, and carbohydrate contents, and their pigment content and photosynthetic efficiency. The results showed that superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities and proline content of four Rhododendrons had a significant difference in autumn and were insignificant in summer. Specifically, R. aganniphum had the maximum protective enzyme activity and proline content in winter as well as chl a, b, and car contents. The values of maximal quantum yield (Fv/Fm), photochemical efficiency (ΦPSII), and non-photochemical quenching (NPQ) of four Rhododendrons were significantly higher in summer than in other seasons. The lower qP indicated the four Rhododendrons were susceptible to photoinhibition. Overall, the four Rhododendrons had similar physical characteristics in subalpine habitats. The parameters of the maximum quantum yield of photosystem II (PSII), the actual quantum yield of PSII, the non-photochemical chlorophyll fluorescence quenching, and chlorophyll a content increased in summer. Meanwhile, the protective enzyme activity and total soluble sugar content, proline content, and carotenoid content increased in spring, autumn, and winter. These results suggested that the four Rhododendrons can adapt to subalpine habitats by heat dissipation to avoid the damage of excessive radiation during the warm season while scavenging reactive oxygen and increasing the intracellular fluid concentration to avoid damage caused by chilling temperatures during the cold seasons. These findings would provide a reference for the conservation and application of these valuable ornamental evergreen broadleaf Rhododendrons, and enrich theory of plant eco-physiology in the high altitudes of the QTP. [ABSTRACT FROM AUTHOR]

Background: Mepiquat chloride (DPC) enhances the resistance of cotton plants, and it is widely used as a growth regulator. DPC can stimulate photosynthesis, stabilize the structure of cotton leaves, and affect population reproduction and energy substances in Aphis gossypii Glover (cotton aphids), but interactions between DPC and cotton aphids remain unclear. In this study, we analyzed the physiological responses of cotton to DPC, and the toxicity of DPC toward cotton aphids, before and after feeding, to explore the DPC-induced defense mechanism against cotton aphids. Results: Measurements of protective enzyme activity in cotton showed that the soluble protein contents, peroxidase (POD) activity, and catalase (CAT) activity in cotton treated with different concentrations of DPC were higher than in the control. Superoxide dismutase (SOD) activity was higher than that of the control when the concentration of DPC was < 0.1 g/L. Under aphid feeding stress, POD activity in cotton treated with a low insect population density was significantly lower than in the controls, but the reverse was true for cotton treated with a high insect population density, and SOD activity was positively correlated with population density. The activities of detoxification enzymes in field and laboratory experiments showed that DPC promoted the specific activity of glutathione S-transferase (GST) in cotton aphids, while the specific activities of carboxylesterase (CarE) and acetylcholinesterase (AchE) were decreased. Conclusions: DPC enhanced the aphid resistance in cotton by increasing the soluble protein content and the activity of protective enzymes. It also had a toxic effect on cotton aphids by increasing GST activity (the main DPC target). DPC increased the soluble protein content and protective enzymes activity in cotton under aphid stress, and thereby enhanced tolerance to cotton aphids. It conclude that DPC interferes with cotton aphids through indirect (DPC induced cotton defense responses) and direct (DPC toxicity to cotton aphids) ways, which plays a positive role in interfering with cotton aphids. [ABSTRACT FROM AUTHOR]

Transgenic cry1Ab/cry1Ac rice (Huahui 1) is able to control the stored pest Plodia interpunctella.Our previous study confirmed that the enzymatic activities of three major antioxidases, including POD, CAT,and SOD, could be significantly changed after short-term stressed with these Bt containing rice. This study focused on the characteristics of rice during storage, the results showed that the Bt protein content in rice husk and brown rice was 5.534 μg/g and 1.003 μg/g respectively, and after 270 days at 25 ℃, the degradation rate was 67.3% and 27.7%, respectively. Moreover, the enzymatic activities of three antioxidases in P.interpunctella long-term fed with transgenic cry1Ab/cry1Ac rice powder would be addressed by enzymatic detection assays. Our data showed that the SOD activities could be significantly inhibited by the Bt containing rice after fed with Bt-rice powder for 12 days or 5 months, However, the enzymatic activities of POD and CAT significantly increase with the concentrations of Bt toxins. In addition, the change trend of protective enzyme activity in the Indian Meal Moth fed with transgenic rice flour for 5 months was consistent with that after 12 days of feeding. Our researches find that there are differences in the trend of increase and decrease of the three major protective enzymes after fed with Bt containing rice powder for a long time,which indicates that the expression mechanisms of the three protective enzymes might be different. Our results provide a theoretical basis for the study of toxicology and related resistance mechanism of transgenic Bt crops.

Priming of seed is an approach that imparts stress tolerance to germinating seeds and seedlings under stressful conditions. Drought stress is a key reason for crop failures. We evaluated the effects of seed priming with 2.5% & 5% & KNO3 and 3% & 3.5% SiO2 on germination, seedling growth, protective enzymes and biochemical attributes of 3-weeks old FARO44 rice seedlings under drought conditions induced by polyethylene glycol (PEG6000). Priming experiments were arranged in a completely randomized design with every treatment replicated five times. The results revealed that KNO3 and SiO2 priming significantly enhanced germination, seedling growth, catalase, and ascorbate peroxidase and superoxide dismutase activities of rice seedlings about 2 folds compared to unprimed seedlings under drought. Priming treatments also improved protein, total chlorophyll, carbohydrate, soluble sugar and proline contents & decreased malondialdehyde content and leaf electrolyte leakage of rice seedlings. Between the two treatments, KNO3 priming was found to be more effective on enhancing germination, protective enzymes' activities and biochemical attributes of rice seedlings. Thus, FARO44 rice priming with KNO3 is suggested for faster germination and growth of seedlings in dry ecosystems. [ABSTRACT FROM AUTHOR]

Drought affects plant growth and has become a serious problem worldwide. Populus species have different drought tolerance and sensitivity abilities. In order to evaluate the mechanism of drought stress tolerance in different cultivated Populus species distributed in China, the response to drought in the morphology and physiology of three poplars clones, NL-895, NL-351 and NL-3412 was investigated. The growth, gas exchange capacity, water use efficiency, antioxidant enzyme activity and lipid peroxidation were measured in order to evaluate differences among different genotypes in responses to two watering regimes (80% and 30% of field capacity). Our results indicated that drought stress had serious adverse effects on the seedlings as the biomass, leaf area, nett photosynthetic rate (Pn) and chlorophyll content were decreased while the activities of antioxidative enzymes were increased and the relative electric conductivity and malondialdehyde (MDA) content were enhanced. The results showed Populus possessed an effective self-protective mechanism to relieve the inhibition of growth induced by water deficit through increasing waster use efficiency, adjusting osmotic membrane and decreasing plant growth. These findings deepened our understanding of drought-tolerance mechanism in Populus. [ABSTRACT FROM AUTHOR]

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Drought stress influences the growth of plants and thus grafting has been widely used to improve tolerance to abiotic stresses. Poplars possess sex-specific responses to drought stress, but how male or female rootstock affect the grafted plant is little known. To explore the mechanisms underlying changes in drought tolerance caused by grafting, we investigated the changes in growth, leaf traits, gas exchange and antioxidant enzyme activities of reciprocally grafted seedlings between Populus euramericana cv. "Nanlin895" (NL-895) (female) and Populus deltiodes cv." 3412 " (NL-3412) (male) under water deficit stress with 30% field capacity for 30 d. Results showed that drought stress affected adversely growth, morphological, and physiological characteristics in all seedlings studied. Grafted seedlings with male roots can effectively alleviated the inhibition of growth induced by drought stress, as shown by higher WUE, activities of SOD, POD and CAT, and lower levels of lipid peroxidation. Male seedlings with female roots were found to be less tolerance to drought than non-grafted male clones and female scions with male roots, but more tolerance than non-grafted female clones. This results suggested that drought tolerance of grafted seedlings is primarily caused by the rootstock, although the scion also affects the grafted plant. Thus, paying attention on the root genotype can provide an important means of improving the drought tolerance of poplars. • Grafted poplars with male roots can effectively alleviated the inhibition of growth induced by drought stress. • Both scion and rootstock can influence the drought tolerance of grafted poplars. • Drought tolerance of poplars is primarily caused by the root. [ABSTRACT FROM AUTHOR]

Physical fractionation of a municipal solid waste compost was performed by a dry sieving process to obtain two particle size fractions (> 1.6 mm and 0.8–1.6 mm). The compost with the two particle sizes and the whole unfractionated compost were applied to field soil, and the effect of different size fractions of compost on the growth and physiological characteristics of Lolium perenne L. were investigated. The results showed that the plant height and shoot biomass of L. perenne were higher in the treatments with the whole compost and > 1.6 mm size fraction compared with the control throughout the growing season, but the difference between treatments decreased gradually. The chlorophyll content in these two treatments was also higher than that in the control. The biomass, chlorophyll b, and total chlorophyll content of the second harvest were 23.8%, 82.1%, and 13.9%, respectively, higher in the > 1.6 mm size fraction treatment than in the control. In addition, L. perenne had a dark green color and uniform plants in the > 1.6 mm fraction treatment, which scored the highest in the comprehensive evaluation of turf quality. Plants treated with the coarse fraction of > 1.6 mm showed a strong photosynthetic capacity and maintained a high protective enzyme activity and proline content to improve stress resistance. [ABSTRACT FROM AUTHOR]

Background Lecanicillium lecanii is an entomopathogenic fungi, which was isolated from insects suffering from disease. Now, it is an effective bio-control resource that can control agricultural pests such as whitefly and aphids. There are many studies on the control of various agricultural pests by L. lecanii, but no report on its control of Bemisia tabaci biotype-Q exists. In this work, we studied the susceptibility of B. tabaci Q-biotype (from Ningxia, China) to L. lecanii JMC-01 in terms of nymph mortality and the changes in detoxifying protective enzymes activities. Methods B. tabaci nymphs were exposed to L. lecanii JMC-01 conidia by immersion with the host culture. Mortality was assessed daily for all nymph stages. The detoxifying and protective enzyme activity changes, weight changes, and fat, and water contents of the nymphs were determined spectrophotometrically. Results All instars of B. tabaci died after being infested with 1 × 108 conidia/mL. The 2nd-instar nymphs were the most susceptible, followed by the 3rd-instar nymphs. The corrected cumulative mortality of the 2nd- and 3rd-instar nymphs was 82.22% and 75.55%, respectively. The levels of detoxifying and protective enzymes initially increased and then decreased. The highest activities of carboxylesterase, acetylcholinesterase, peroxidase, and catalase occurred on the 3rd day, reaching 10.5, 0.32, 20, and 6.3 U/mg prot, respectively. These levels were 2.2-, 4.3-, 2.4-, and 1.4-fold the control levels, respectively. The highest activities of glutathione-S transferase and superoxide dismutase on the 2nd day were, respectively, 64 and 43.5 U/mg prot. These levels were, respectively, 2.7 and 1.1-fold that of the control level. The water and fat content in the infected B. tabaci nymphs decreased and differed significantly from the control levels. The weight increased continuously in the first 24 h, decreasing thereafter. At 72 h, the infestation level was about 0.78-fold that of the control level. Conclusions The studied L. lecanii JMC-01 strain is pathogenic to the B. tabaci Q-biotype. This strain interferes with the normal functioning of detoxifying and protective enzymes, and is also involved in the disruption of normal physiological metabolism in B. tabaci.

Effects of beta-cypermethrin, abamectin, chlorpyrifos, thiamethoxam and bisultap on toxicity against 1st-6th instar larvae in Phauda flammans Walker (Lepidoptera: Zygaenidae) were tested using the leaf-dipping method. Meanwhile, effects of these pesticides on detoxifying and protective enzymes in P. flammans larvae were also measured. Results showed that the LC50 value of beta-cypermethrin, abamectin, chlorpyrifos, thiamethoxam and bisultap against P. flammans larvae were related to the instar and pesticide. Control efficacy of beta-cypermethrin was the best among of these pesticides, and the LC50 value of which against 1st instar larvae in P. flammans reached 2.038 mg/L at 8 h after treatment, and reached 6.416-48.764 mg/L for 2nd-6th instar larvae at 24 h after treatment. Control efficacy of abamectin was less than beta-cypermethrin, and the LC50 value of which against 1st instar larvae in P. flammans reached 241.953 mg/L at 8 h after treatment, and reached 19.285-266.207 mg/L for 2nd-6th instar larvae at 24 h after treatment. Control efficacy of chlorpyrifos, thiamethoxam and bisultap was less than the first two pesticides. Changes of detoxifying and protective enzymes in P. flammans larvae were related to the kinds of enzyme and its sensitivity to pesticide after treatment with different pesticides. Compared with control, effect of beta-cypermethrin on Carboxylesterase (CarE) was the most obvious than other four pesticides; activity of glutathione-s transferase (GST) was inhibited by abamectin, while the trend was in the opposite direction for other four pesticides; activity of superoxide dismutase (SOD) was promoted by beta-cypermethrin and chlorpyrifos, and inhibited by abamectin and bisultap; Activity of catalase (CAT) was promoted by beta-cypermethrin, chlorpyrifos and bisultap, inhibited the influence of promotion by thiamethoxam. Results suggested that P. flammans larvae could be effectively controlled by betacypermethrin 10 mg/L and abamectin 25 mg/L with alternate spray, which could prevent the resistance to pesticides in this pest. [ABSTRACT FROM AUTHOR]

Eleven isolates of Beauveria spp., including B. bassiana (BbO62) newly isolated from Helicoverpa assulta, and other seven B. bassiana isolates and three B. brongniartii isolates that were originally isolated from different geographic origins and various hosts, were tested against the 3rd instar larvae of H. assulta. The protective enzyme activity in the 3rd larvae of H. assulta infected by highly virulent isolate was also assayed. The results showed that the isolate BbO62 had the highest virulence to the 3rd instar larvae among eleven isolates of Beauveria spp., with a corrected mortality reaching 91.07% within 10 d post treatment, and the LT50 was 4.67 d. After inoculated with three concentrations (1.0x106, 1.0x107 and 1.0x108 conidia/mL) of BbO62 comdial suspension, the accumulative mortality of H. assulta larvae increased with the increase of concentration and observation time, and the LC50 was 1.82x107 conidia/mL. Activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in H. assulta larvae first increased rapidly then dropped sharply within 72 h. BbO62 showed high virulence to H. assulta and could inhibit activities of protective enzymes. Therefore, it will be a promising biocontrol agent against H. assulta. [ABSTRACT FROM AUTHOR]

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Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Autotoxicity has been considered as one of the critical factors resulting in replanting failure in agriculture. To clarify the chemical reasons for the replanting problems of Pinellia ternate , a widely used and cultivated Traditional Chinese Medicine, eight compounds were isolated and identified from its rhizosphere soil. Bioassays showed that chrysophanol ( 1 ), benzofuran ( 6 ) and protocatechuic aldehyde ( 8 ) obviously inhibited the seedling growth of P. ternate and Raphanus sativus in a concentration-dependent manner. The isolated compounds were further confirmed and quantified by HPLC in the rhizosphere soil and tissues of P. ternate , and the origins of the allelochemicals being released into the soil environment were also investigated. Physiological analyses demonstrated that the allelochemicals evidently affected the levels of protective enzymes in the tested plant seedlings and caused membrane damage, which resulted in the reduction of cell vitality. These findings provide allelopathic evidence for the replanting problems of P. ternate and would be helpful for assessing plant-soil interactions. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the efficacy of combinations of Serratia marcescens isolate S-JS1 and insecticides against Laodelphax striatellus, and to investigate the effect of S. marcescens on the detoxifying and protective enzymes of L. striatellus. Third-instar nymphs of L. striatellus were used in all experiments. The efficacy of 5 insecticides (spirotetramat, thiamethoxam, imidacloprid, acetamiprid, and chlorpyrifos) alone and mixed with S. marcescens against L. striatellus were compared by spraying method. After L. striatellus feeding on S. marcescens-treated rice seedling, the activity changes of carboxylesterase (CarE), glutathione-S-transferases (GSTs), peroxidase (POD), and superoxide dismutase (SOD) in it were determined. The results showed that combinations of S. marcescens with insecticide of any concentration resulted in higher L. striatellus mortality compared to the effect achieved by insecticide alone. Compared to the mortality effect against L. striatellus using 1.25 mg/L thiamethoxam (44.24%) or 25 mg/L spirotetramat (49.22%), applications of 109 cfu/mL S. marcescens + 1.25 mg/L thiamethoxam for 3 days (65.58%) or 109 cfu/mL S. marcescens + 25 mg/L spirotetramat for 5 days (76.27%) show significantly higher activities. And interactions resulted in a synergistic responses (χ2 < 3.84, observed mortality - expected mortality > 0). Other combination treatments of S-JS1 with insecticide of any concentrations all exhibited additive interactions. 12 and 24 h after L. striatellus feeding on S. marcescens-treated rice seedling, there was no significant difference in CarE activity between the treatment group and the control group. The activity of GSTs increased initially, then decreased. The activities of POD and SOD were always significantly lower than those in the control. Therefore, S. marcescens S-JS1 may weaken the defense activity of L. striatellus against insecticides. This study provides reference for exploring the combined applications of entomopathogenic bacteria and insecticides, and may provide a novel clue for the control of L. striatellus. [ABSTRACT FROM AUTHOR]

Key message: Under warming condition, growth of Cunninghamia lanceolata is not accompanied by increased photosynthetic performance. The combination of warming and N addition seemed to adversely influence leaf carbon balance as Rd/Pnmax and endogenous hormones were strongly affected.Abstract: Uncertainties about the response of plant eco-physiological mechanisms to elevated temperature and nitrogen (N) deposition make it difficult to predict the performance of plants under future climatic conditions in the sub-tropical regions. We measured photosynthetic parameters, the contents of osmoregulatory substances, oxidant substances, protective enzymes, and endogenous hormones in Cunninghamia lanceolata under conditions of soil warming and N addition. We used six treatments: (1) unwarmed and unfertilized (CT), (2) unwarmed and high N (HN), (3) unwarmed and low N (LN), (4) warmed and unfertilized (W), (5) warmed and high N (WHN), and (6) warmed and low N (WLN). We found that the Rd/Pnmax was the lowest in the W treatment, but the height was almost with the same as that of the CT. Plants under W showed plasticity of protective capacity by increasing peroxidase contents. N addition enhanced photosynthesis and promoted growth. The WLN treatments increased Rd/Pnmax and decreased indoleacetic acid, gibberellin, and cytokinin contents, which might caused reduction in the absorption of nutrients and growth of the plants in the short-term. There were no significant differences in the content of osmoregulatory substances among the different treatments. We conclude different mechanisms may exist between W and N addition treatments that probably depend on adjustments through the physiological and biophysical processes. This study provides a new reference for forest management in view of the future climate changes. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Paranosema locustae is an entomopathogenic microsporidia with promising potential for controlling agricultural pests, including Locusta migratoria manilensis. However, it has the disadvantage of having a slow insecticidal rate, and how P. locustae infection impacts the host immune response is currently unknown. The present study investigated the effect of P. locustae on the natural immune response of L. migratoria and the activities of enzymes that protect against oxidative stress. Infection with P. locustae increased the hemocytes and nodulation number of L. migratoria at the initial stage of infection. The hemocyte-mediated modulation of immune response was also affected by a decrease in the number of hemocytes 12 days postinfection. Superoxide dismutase activity in locusts increased in the early stages of infection but decreased in the later stages, whereas the activities of peroxidase (POD) and catalase (CAT) showed opposite trends may be due to their different mechanisms of action. Furthermore, the transcription levels of mRNA of antimicrobial peptide-related genes and phenoloxidase activity in hemolymph in L. migratoria were suppressed within 15 days of P. locustae infection. Overall, our data suggest that P. locustae create a conducive environment for its own proliferation in the host by disrupting the immune defense against it. These findings provide useful information for the potential application of P. locustae as a biocontrol agent., (© 2023 Wiley Periodicals LLC.)

Polysaccharides isolated from Chrysanthemum indicum were studied for their pathogen-derived resistance against Sclerotium rolfsii sacc in Atractylodis maceocephalae koidz . The total sugar content and monosaccharide analysis were determined by phenol–sulfuric acid method and gas chromatography, and infrared spectroscopy performed for simple structure information. The activities of CAT and POD as protective enzymes in A. maceocephalae leaves were evaluated. The purified polysaccharides exhibited strong CAT and POD activities in inoculated with S. rolfsii in A. macrocephala leaves, attained the maximum value 568.3 Ug −1 min −1 and 604.4 Ug −1 min −1 respectively. Whereas, when compared with the control plants, 20 mg/ml purified polysaccharides exhibited the strongest CAT and POD activities. Notably, the treatments of A. macepcephalae seedlings with C. indicum polysaccharides (CIP) decreased disease index development caused by S. rolfsii . The disease index after 10 days was significantly reduced when the seedlings treated with 20 mg/ml CIP, 4.41 compared to the control plants 32.00. Given together, these results indicated that purified polysaccharides derived from C. indicum may be useful as a natural inducer. [ABSTRACT FROM AUTHOR]

Salt stress causes oxidative damage in plants, and it induces protective mechanisms through enzymatic and non-enzymatic components of the antioxidant system. Different components of this system exhibit specific degrees of tolerance toward certain salt concentrations. Their differential responses may contribute not only to a better understanding of the functional interconnections in the antioxidant defense system, but also to a more efficient selection of physiological and biochemical markers of stress reactions of plants, in the effort for an early and precise bioindication of oxidative damage caused by high salinity of the environment. In this context, the molar ratio between the reduced and the oxidized form of ascorbic acid is a more sensitive marker of oxidative stress than the total amount of this vitamin in the biomass of lesser duckweed. Glutathione content exhibits a more moderate variation with increasing salt stress than the concentration of carotenoid pigments in the fronds exposed to constant photon flux density. From among the antioxidant enzymes, ascorbate peroxidase was found to be the most sensitive, and superoxide dismutase was the most resistant to oxidative stress caused by increasing salinity. Catalase and glutathione reductase activities decreased under severe salt stress. Efficiency of the antioxidant system can be monitored by membrane damage through lipid peroxidation. Antioxidants of duckweed are useful tools for indication of increasing salinity of aquatic environments. [ABSTRACT FROM AUTHOR]