Search

Sugar is a natural food and a common organic compound that widely exists in nature. Sugar features easy patterning, solubility in water, environmental friendliness, low cost, and easy combination with micro-nano process. In this study, sugar is proposed to be used as a micro-nano mask material in micro-nano fabrication. Results show that sugar can be easily used to fabricate various kinds of micro-nano mask patterns on different wettability substrates. The fabrication method based on sugar mask has many advantages; it is diverse, simple, pollution-free, and inexpensive. Besides, sugar is strongly compatible with micro-nano fabrication technology, because it can maintain good peeling properties, good viscosity, and good stability in subsequent micro-nano fabrication and achieve the high-quality transfer of mask patterns. In addition, graphite super-lubricity micro-nano movable devices are made through the proposed sugar mask method, which also has good and reliable performance compared with e-beam lithography. Compared with micro-nano fabrication based on photoresist masks, micro-nano fabrication based on the sugar mask is simpler and cheaper. In the micro-nano processing of the sugar mask, the lift-off and removal of residual sugar can be easily completed using water. In summary, we believe that sugar as a mask material is effective and can be widely used in micro-nano manufacturing. [ABSTRACT FROM AUTHOR]

In traditional food industry, the assessment of mushy materials plays an important role in high‐quality food production, which still relies heavily on human tactile perception. In this work, to address this issue for enhancing food production efficiency, a flexible electret tactile sensor that can mimic expert touch is developed. The sensor consists of a pair of electrodes, a microstructural spacer, and a pre‐charged electret. Benefiting from the electrostatic induction‐based working mechanism, the sensor attains high sensitivity and is ideal for precise sensing in actions similar to those of skilled Baijiu distillers. Due to its hermetic and electromagnetic interference‐resistant encapsulation with polypropylene/aluminum/parylene films, the sensor remained durable in vinasse in the real distillery, with its high water and alcohol content, for over 21 days. This demonstrates its long‐term stability in harsh environment. Based on the proposed flexible electret tactile sensor, an automated and intelligent vinasse identification system is built, mimicking the actions of Baijiu distillers in vinasse assessment. Combining tactile sensing data with machine learning, the system can distinguish 8 kinds of vinasses with different ingredient ratios, achieving an accuracy of 98%. This work significantly demonstrates the practical potential of the sensor in the food industry. [ABSTRACT FROM AUTHOR]

Environmental pollution has gained negative attention in recent years. The pesticides and heavy metals are top list of environmental toxicants directly endangering the survival and development of Apis cerana cerana. Cyclin-dependent kinases (CDKs) are heteromeric serine/threonine kinases that participate in cell cycle regulation and have a vital role in pesticide and heavy metal stress in Apis cerana cerana. In this experiment, we filtered out CDK8 gene from Apis cerana cerana (AccCDK8) and investigated its functions of pesticide and heavy metals resistance. Sequence analysis indicated that AccCDK8 is highly homologous to multiple CDK8s and contains a highly conserved CDK active site sequence. Phylogenetic analysis showed that AmCDK8 and AccCDK8 were closely related evolutionarily in Apis mellifera. Transcriptome analysis revealed that AccCDK8 expression was differentially affected after exposure to pesticide and heavy metal stresses. This indicates that AccCDK8 has a significant role in the resistance of Apis cerana cerana to pesticide and heavy metal stresses. It has implications for studying the function of CDK in other insects in response to stress. [Display omitted] • Pesticides and heavy metals affect the survival of Apis cerana cerana. • CDK8 takes part in the oxidative stress response of Apis cerana cerana. • CDK8 is involved in the growth and reproduction of Apis cerana cerana. • AccCDK8 plays an important role in pesticide and heavy metals stresses. • We highlight the effects of some pesticides on the health of Apis cerana cerana. [ABSTRACT FROM AUTHOR]

BACKGROUND: Environmental stress can induce oxidative stress in Apis cerana cerana, leading to cellular oxidative damage, reduced vitality, and even death. Currently, owing to an incomplete understanding of the molecular mechanisms by which A. cerana cerana resists oxidative damage, there is no available method to mitigate the risk of this type of damage. Cyclin plays an important role in cell stress resistance. The aim of this study was to explore the in vivo protection of cyclin H against oxidative damage induced by abiotic stress in A. cerana cerana and clarify the mechanism of action. We isolated and identified the AccCyclin H gene in A. cerana cerana and analysed its responses to different exogenous stresses. RESULTS: The results showed that different oxidative stressors can induce or inhibit the expression of AccCyclin H. After RNA‐interference‐mediated AccCyclin H silencing, the activity of antioxidant‐related genes and related enzymes was inhibited, and trehalose metabolism was reduced. AccCyclin H gene silencing reduced A. cerana cerana high‐temperature tolerance. Exogenous trehalose supplementation enhanced the total antioxidant capacity of A. cerana cerana, reduced the accumulation of oxidants, and improved the viability of A. cerana cerana under high‐temperature stress. CONCLUSION: Our findings suggest that trehalose can alleviate adverse stress and that AccCyclin H may participate in oxidative stress reactions by regulating trehalose metabolism. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The tumor vasculature was different from the normal vasculature in both function and morphology, which caused hypoxia in the tumor microenvironment (TME). Previous anti-angiogenesis therapy had led to a modest improvement in cancer immunotherapy. However, antiangiogenic therapy only benefitted a few patients and caused many side effects. Therefore, there was still a need to develop a new approach to affect tumor vasculature formation. The CD93 receptor expressed on the surface of vascular endothelial cells (ECs) and its natural ligands, MMRN2 and IGFBP7, were now considered potential targets in the antiangiogenic treatment because recent studies had reported that anti-CD93 could normalize the tumor vasculature without impacting normal blood vessels. Here, we reviewed recent studies on the role of CD93, IGFBP7, and MMRN2 in angiogenesis. We focused on revealing the interaction between IGFBP7-CD93 and MMRN2-CD93 and the signaling cascaded impacted by CD93, IGFBP7, and MMRN2 during the angiogenesis process. We also reviewed retrospective studies on CD93, IGFBP7, and MMRN2 expression and their relationship with clinical factors. In conclusion, CD93 was a promising target for normalizing the tumor vasculature. [ABSTRACT FROM AUTHOR]

BACKGROUND: The widespread use of glyphosate has many adverse effects on Apis cerana cerana. Due to the incomplete understanding of the molecular mechanisms of glyphosate toxicity, there are no available methods for mitigating the threat of glyphosate to Apis cerana cerana. Small heat shock proteins (sHSPs) play an important role in resisting oxidative stress, but their mechanism of action in Apis cerana cerana remains unclear. RESULTS: In this experiment, we cloned and identified AccsHSP21.7. Studies have shown that AccsHSP21.7 contains binding motifs for various transcription factors related to oxidative stress. Abiotic stresses induced the expression of AccsHSP21.7. Bacteriostatic testing of a recombinant AccsHSP21.7 protein proved that Escherichia coli overexpressing AccsHSP21.7 showed increased resistance to oxidative stress. Knocking down the AccsHSP21.7 gene caused significant damage to midgut cells, which seriously disrupted the antioxidant system in Apis cerana cerana and greatly increased mortality under glyphosate stress. CONCLUSION: This study investigated the relationship between antioxidant regulation and the AccsHSP21.7 gene at the molecular level, and the results have guiding significance for the improvement of stress resistance in Apis cerana cerana. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The protein kinase (PK, kinome) family is one of the largest families in plants and regulates almost all aspects of plant processes, including plant development and stress responses. Despite their important functions, comprehensive functional classification, evolutionary analysis and expression patterns of the cotton PK gene family has yet to be performed on PK genes. In this study, we identified the cotton kinomes in the Gossypium raimondii, Gossypium arboretum, Gossypium hirsutum and Gossypium barbadense genomes and classified them into 7 groups and 122–24 subfamilies using software HMMER v3.0 scanning and neighbor-joining (NJ) phylogenetic analysis. Some conserved exon-intron structures were identified not only in cotton species but also in primitive plants, ferns and moss, suggesting the significant function and ancient origination of these PK genes. Collinearity analysis revealed that 16.6 million years ago (Mya) cotton-specific whole genome duplication (WGD) events may have played a partial role in the expansion of the cotton kinomes, whereas tandem duplication (TD) events mainly contributed to the expansion of the cotton RLK group. Synteny analysis revealed that tetraploidization of G. hirsutum and G. barbadense contributed to the expansion of G. hirsutum and G. barbadense PKs. Global expression analysis of cotton PKs revealed stress-specific and fiber development-related expression patterns, suggesting that many cotton PKs might be involved in the regulation of the stress response and fiber development processes. This study provides foundational information for further studies on the evolution and molecular function of cotton PKs. [ABSTRACT FROM AUTHOR]

Cuticular proteins (CPs) are known to play important roles in insect development and defence responses. The loss of CP genes can lead to changes in insect morphology and sensitivity to the external environment. In this study, we identified the AccCPR2 gene, which belongs to the CPR family (including the R&R consensus motif) of CPs, and explored its function in the response of Apis cerana cerana to adverse external stresses. Our results demonstrated that AccCPR2 was highly expressed in the late pupal stage and epidermis, and the expression of AccCPR2 may be induced or inhibited under different stressors. RNA interference experiments showed that knockdown of AccCPR2 reduced the activity of antioxidant enzymes, led to the accumulation of oxidative damage and suppressed the expression of several antioxidant genes. In addition, knockdown of AccCPR2 also reduced the pesticide resistance of A. cerana cerana. The overexpression of AccCPR2 in a prokaryotic system further confirmed its role in resistance to various stresses. In summary, AccCPR2 may play pivotal roles in the normal development and environmental stress response of A. cerana cerana. This study also enriched the theoretical knowledge of the resistance biology of bees. [ABSTRACT FROM AUTHOR]

Summary: WRKY transcription factors (TFs) are crucial regulators in response to pathogen infection. However, the regulatory mechanisms of WRKY TFs in response to Fusarium oxysporum f. sp. vasinfectum (Fov), the most devastating pathogen of cotton, remain unclear.Here, transcriptome sequencing indicated that the group IIc WRKY TF subfamily was the most important TF subfamily in response to Fov. Gain‐of‐function and loss‐of‐function analyses showed that group IIc WRKY TFs positively regulated cotton resistance to Fov. A series of chromatin immunoprecipitation sequencing, yeast one‐hybrid assay and electrophoresis mobility shift assay experiments indicated that group IIc WRKY TFs directly bound to the promoter of GhMKK2 and regulated its expression.Importantly, a novel mitogen‐activated protein kinase (MAPK) cascade composed of GhMKK2, GhNTF6 and GhMYC2 was identified. The functional analysis indicated that group IIc WRKY TFs induced the GhMKK2‐GhNTF6 pathway to increase resistance to Fov by upregulating the GhMYC2‐mediated expression of several flavonoid biosynthesis‐related genes, which led to flavonoid accumulation.In conclusion, our study demonstrated a novel disease defense mechanism by which the WRKY‐MAPK pathway promotes flavonoid biosynthesis to defend against pathogen infection. This pathway improves our understanding of the interaction mode between WRKY TFs and MAPK cascades in plant immunity and the vital role of plant flavonoids in pathogen defense. [ABSTRACT FROM AUTHOR]

In the present study, we identified and characterized two small heat shock protein genes from Apis cerana cerana, named AccHsp24.2 and AccHsp23.0. An alignment analysis showed that AccHsp24.2 and AccHsp23.0 share high similarity with other members of the α-crystallin/sHSP family, all of which contain the conserved α-crystallin domain. The recombinant AccHsp24.2 and AccHsp23.0 proteins were shown to have molecular chaperone activity by the malate dehydrogenase thermal aggregation assay. Three heat shock elements were detected in the 5′-flanking region of AccHsp24.2 and eleven in AccHsp23.0, and two Drosophila Broad-Complex genes for ecdysone steroid response sites were found in each of the genes. The presence of these elements suggests that the expression of these genes might be regulated by heat shock and ecdysone, which was confirmed by quantitative RT-PCR (RT-qPCR). The results revealed that the expression of the two genes could be induced by cold shock (4°C) and heat shock (37°C and 43°C) in an analogous manner, and AccHsp24.2 was more susceptible than AccHsp23.0. In addition, the expression of the two genes was induced by high concentrations of ecdysone in vitro and in vivo. The accumulation of AccHsp24.2 and AccHsp23.0 mRNA was also detected in different developmental stages and tissues. In spite of the differential expression at the same stage, these genes shared similar developmental patterns, suggesting that they are regulated by similar mechanisms. [ABSTRACT FROM AUTHOR]

Key message: We report that GhWRKY21, a WRKY transcription factor, plays essential roles in regulating the intensity of the drought-induced ABA signalling pathway by facilitating the expression of GhHAB in cotton (Gossypium hirsutum). Abscisic acid (ABA) is one of the most important plant hormones in response to abiotic stress. However, activation of the ABA signalling pathway often leads to growth inhibition. The mechanisms that regulate the intensity of ABA signals are poorly understood. Here, we isolated and analysed the cotton group IId WRKY transcription factor (TF) gene GhWRKY21. Functional analysis indicated that GhWRKY21 plays a negative role in the drought response of cotton. Silencing of GhWRKY21 in cotton dramatically increased drought tolerance, whereas ectopic GhWRKY21 overexpression in Nicotiana benthamiana decreased drought tolerance. Furthermore, the GhWRKY21-mediated drought tolerance was ABA dependent. To clarify the mechanism underlying the GhWRKY21-mediated regulation of drought tolerance, 17 clade-A-type type 2C protein phosphatase (PP2C) genes, which are negative regulators of ABA signalling, were identified in cotton. Notably, GhWRKY21 interacted specifically with the W-box element within the promoter of GhHAB and regulated its expression. Silencing of GhHAB in cotton yielded a phenotype similar to that of GhWRKY21-silenced cotton. These results suggest that GhWRKY21 regulates the intensity of ABA signals by facilitating the expression of GhHAB. In summary, these findings dramatically improve our understanding of the function of WRKY TFs and provide insights into the mechanism of ABA-mediated drought tolerance. [ABSTRACT FROM AUTHOR]

Abstract: Previous studies have demonstrated that mammalian thioredoxin reductases 1 (TrxRs; EC 1.6.4.5) play roles in protection against oxidant injury, cell growth and transformation, and the recycling of ascorbate from its oxidized form. However, little is known about the function of TrxRs in insects, especially in Apis cerana cerana. To gain a better understanding of its role in insects, we cloned TrxR1 from A. cerana cerana (AccTrxR1) and investigated its structural features and expression. The full-length cDNA is 1998bp long and contains an open reading frame (ORF) of 1485bp. The deduced AccTrxR1 protein has 494 aa, a calculated molecular mass (MW) of 54.24kDa, and an isoelectric point of pH 7.35. The full-length genomic DNA of AccTrxR1 is 3500bp and contains eight exons and seven introns. In addition, the sequence and putative transcription factor-binding sites of the 5′-flanking region were examined. We also looked for conserved domains/motifs, generated homologous alignments, conducted phylogenetic analysis, and made secondary and tertiary structure predictions using web software. RT-PCR revealed that the expression of AccTrxR1 could be induced by UV and heat (37°C). These results indicate that AccTrxR1 may play a key role in protection against oxidant stress. [Copyright &y& Elsevier]

Abstract: Phospholipid hydroperoxide glutathione peroxidase (PHGPX) plays a crucial role in maintaining the integrity of membrane by reducing hydroperoxides of phospholipids. Here, we report the identification and characterization of two genes, designated AccGtpx-1 and AccGtpx-2, encoding PHGPX proteins from the Chinese honeybees, Apis cerana cerana. Alignment analysis showed that AccGtpx-1 and AccGtpx-2 shared high similarity with other known PHGPXs, which show similar structure to thioredoxin. These single copy genes showed complex exon–intron structures. The mRNA of AccGtpx-1 was detected in larvae, pupae and adults and that AccGtpx-2 was only found in adult worker bees. Furthermore, the expression of AccGtpx-1 could be induced by H2O2, ultraviolet (UV) light, heat shock (37°C), HgCl2, imidacloprid, cyhalothrin, pyriproxyfen and methomyl. In contrast, AccGtpx-2 expression could only be induced by UV. These results indicated for the first time that the AccGtpx-1 and AccGtpx-2 genes encoding A. cerana cerana PHGPXs are regulated differently in response to environmental stressors. [Copyright &y& Elsevier]

The demand for waterproofing of polymer (parylene) coating encapsulation has increased in a wide variety of applications, especially in the waterproof protection of electronic devices. However, parylene coatings often produce pinholes and cracks, which will reduce the waterproof effect as a protective barrier. This characteristic has a more significant influence on sensors and actuators with movable parts. Thus, a defect filling method of micro-nano composite structure is proposed to improve the waterproof ability of parylene coatings. The defect filling method is composed of a nano layer of Al2O3 molecules and a micro layer of parylene polymer. Based on the diffusion mechanism of water molecules in the polymer membrane, defects on the surface of polymer encapsulation will be filled and decomposed into smaller areas by Al2O3 nanoparticles to delay or hinder the penetration of water molecules. Accordingly, the dense Al2O3 nanoparticles are utilized to fill and repair the surface of the organic polymer by low-rate atomic layer deposition. This paper takes the pressure sensor as an example to carry out the corresponding research. Experimental results show that the proposed method is very effective and the encapsulated sensors work properly in a saline solution after a period of time equivalent to 153.9 days in body temperature, maintaining their accuracy and precision of 2 mmHg. Moreover, the sensors could improve accuracy by about 43% after the proposed encapsulation. Therefore, the water molecule anti-permeability encapsulation would have broad application prospects in micro/nano-device protection. [ABSTRACT FROM AUTHOR]

Bees are vitally important in natural and agricultural ecosystems, providing key pollination services to wild plants and crops. Increasing reports of regional declines of bee populations have attracted intense attention worldwide. Challenges to bee health are multifactorial and include poor nutrition, heat stress, agrochemicals, and pathogens. The impact of heat stress is a relatively minor factor in current bee declines compared with agrochemicals and pathogens. However, heat stress has adverse impacts on foraging activity, pollination services, task-related physiology, immunocompetence, reproductive capacity, growth, and development of bees, and these adverse impacts are variable in different bee species. Heat stress–related damage to bees receives extra attention when it is accompanied by climate change. Heat-tolerance mechanisms are key enablers for bee survival under high-temperature stress conditions, and we now understand that both behavior and molecular regulation strongly impact the ability of bees to reduce damage from heat stress. In this review, we summarize and synthesize previous findings about the detrimental effects of heat stress to bees and discuss the strategies bees use to cope with heat stress. Bee species mentioned here are mainly honeybees, bumblebees, and stingless bees, with a focus on the honeybee Apis mellifera. [ABSTRACT FROM AUTHOR]

Odorant-binding proteins (OBPs) play an important role in odour perception and transport in insects. However, little is known about whether OBPs perform other functions in insects, particularly in Apis cerana cerana. Within this study, an OBP gene (AccOBP10) was isolated and identified from A. c. cerana. Both homology and phylogenetic relationship analyses indicated that the amino acid sequence of AccOBP10 had a high degree of sequence identity with other members of the gene family. Analysis of quantitative real-time PCR (qRT-PCR) showed that AccOBP10 mRNA was expressed at higher levels in the venom gland than in other tissues. The mRNA transcript expression of AccOBP10 was upregulated by low temperature (4°C), hydrogen peroxide (H2O2), pyridaben, methomyl and imidacloprid but downregulated by heat (42°C), ultraviolet light, vitamin C, mercuric chloride, cadmium chloride, paraquat and phoxim. Expression of AccOBP10 under abiotic stress was analysed by western blotting, and the results were consistent with those of qRT-PCR. And as a further study of AccOBP10 function, we demonstrated that knockdown of AccOBP10 by RNA interference could slightly increase the expression levels of some stress-related genes. Collectively, these results suggest that AccOBP10 is mainly involved in the response to stress conditions. [ABSTRACT FROM AUTHOR]

As predominant pollinators, honeybees are important for crop production and terrestrial ecosystems. Recently, various environmental stresses have led to large declines in honeybee populations in many regions. The ability of honeybees to respond to these stresses is critical for their survival. However, the details of the stress defense mechanisms of honeybees have remained elusive. Here, we found that the Nuclear Factor Y (NF-Y) family (containing NF-YA, NF-YB, and NF-YC) is a novel stress mediator family that regulates honeybee environmental stress resistance. NF-YA localized in the nucleus, NF-YB accumulated in the cytoplasm, and NF-YC presented in both the nucleus and cytoplasm. NF-YC interacted with NF-YA and NF-YB in vitro and in vivo, and the nuclear import of NF-YB relied on its interaction with NF-YC. We further found that the expression of NF-Y was induced under multiple stress conditions. In addition, NF-Y regulated many stress responses and antioxidant genes at the transcriptome-wide level, and knockdown of NF-Y repressed the expression of stress-inducible genes, particularly LOC108003540 and LOC107994062, under adverse circumstances. Silencing NF-Y lowered honeybee stress resistance by reducing total antioxidant capacity and enhancing oxidative impairment. Collectively, these results indicate that NF-Y plays important roles in stress responses. Our study sheds light on the underlying defense mechanisms of honeybees under environmental stress. [ABSTRACT FROM AUTHOR]

N-Terminal asparagine amidohydrolase is a component of the ubiquitin-dependent N-end rule pathway of protein degradation that has been implicated in a variety of physiological functions, including the sensing of heme, oxygen, nitric oxide, selective elimination of misfolded proteins and the repair of DNA. We identified the Apis cerana cerana N-terminal asparagine amidohydrolase (AccNtan1) gene from A. cerana cerana and investigated its role in oxidation resistance. Multiple sequence alignments and phylogenetic analysis revealed that N-terminal asparagine amidohydrolase is highly conserved in insect species. Quantitative real-time polymerase chain reaction analysis indicated that the expression levels of AccNtan1 were significantly lower in the wing, honey sac and abdomen than in other tissues and were significantly higher in early stages of development, including the larva, prepupa and pink-eyed pupa stages, than in later stages. We further observed that AccNtan1 expression was induced by several environmental stressors, including aberrant temperature, H2O2, UV, heavy metals and pesticides. Moreover, a bacteriostatic assay suggested that overexpression of AccNtan1 enhances the resistance of bacteria to oxidative stress. In addition, knockdown of AccNtan1 using RNA interference significantly affected the expression levels of most antioxidant genes and the activity levels of several antioxidant enzymes. Thus, we hypothesize that AccNtan1 plays important roles in environmental stress responses and antioxidative processes. [ABSTRACT FROM AUTHOR]

Summary: In eukaryotes, MAPK scaffold proteins are crucial for regulating the function of MAPK cascades. However, only a few MAPK scaffold proteins have been reported in plants, and the molecular mechanism through which scaffold proteins regulate the function of the MAPK cascade remains poorly understood. Here, we identified GhMORG1, a GhMKK6‐GhMPK4 cascade scaffold protein that positively regulates the resistance of cotton to Fusarium oxysporum. GhMORG1 interacted with GhMKK6 and GhMPK4, and the overexpression of GhMORG1 in cotton protoplasts dramatically increased the activity of the GhMKK6‐GhMPK4 cascade. Quantitative phosphoproteomics was used to clarify the mechanism of GhMORG1 in regulating disease resistance, and thirty‐two proteins were considered as the putative substrates of the GhMORG1‐dependent GhMKK6‐GhMPK4 cascade. These putative substrates were involved in multiple disease resistance processes, such as cellular amino acid metabolic processes, calcium ion binding and RNA binding. The kinase assays verified that most of the putative substrates were phosphorylated by the GhMKK6‐GhMPK4 cascade. For functional analysis, nine putative substrates were silenced in cotton, respectively. The resistance of cotton to F. oxysporum was decreased in the substrate‐silenced cottons. These results suggest that GhMORG1 regulates several different disease resistance processes by facilitating the phosphorylation of GhMKK6‐GhMPK4 cascade substrates. Taken together, these findings reveal a new plant MAPK scaffold protein and provide insights into the mechanism of plant resistance to pathogens. [ABSTRACT FROM AUTHOR]

As molecular chaperones, DnaJs play critical roles in maintaining cytoplasmic structure and resisting various stresses. However, the functions of DnaJs in insects are poorly understood. In this study, we identified a DnaJC3 from Apis cerana cerana (AccDnaJC3) and investigated its roles in adverse conditions. Real-time quantitative PCR analysis showed that AccDnaJC3 was highly expressed in muscle and epidermis. In addition, AccDnaJC3 was induced by a variety of stresses, such as 4 °C, 24 °C, 44 °C, H 2 O 2 , HgCl 2 , VC, UV, cyhalothrin, abamectin and emamectin benzoate treatments, whereas it was inhibited by CdCl 2 and paraquat treatments. Disc diffusion experiments indicated that overexpression of recombinant AccDnaJC3 enhanced Escherichia coli tolerance to some stress conditions. In contrast to the control group, when AccDnaJC3 was knocked down with RNAi technology, several other antioxidant genes were downregulated, suggesting that AccDnaJC3 may play important roles in stress response. Furthermore, we found that the enzyme activities of superoxide dismutase, peroxidase and catalase were lower in AccDnaJC3 -knockdown bees than in control bees. Taken together, these results suggest that AccDnaJC3 may be involved in various stress responses in Apis cerana cerana. Unlabelled Image • A DnaJC3 gene from Apis cerana cerana was isolated and characterized. • The expression of AccDnaJC3 was induced by various environmental stresses. • AccDnaJC3 enhances the tolerance of Escherichia coli to stress conditions. • RNA interference experiments suggested that AccDnaJC3 is important for resistance against stresses. [ABSTRACT FROM AUTHOR]

Heavy metals and pesticides represent prominent sources of pollution in the natural habitat of Apis cerana cerana , potentially endangering their health through the induction of oxidative stress reactions. This study aimed to address this issue by isolating AccCDK2-like and AccCINP-like proteins from Apis cerana cerana and investigating their functional roles in honey bee resistance against pesticide and heavy metal stresses. Bioinformatics analysis revealed significant homology of these proteins with those found in other species. Functional studies confirmed their participation in interaction with each other, alongside demonstrating distinct patterns of expression and localization. Specifically, AccCDK2-like exhibited higher expression levels in prepupae and muscle tissues, while AccCINP-like showed maximal expression in brown pupae and abdomen. Furthermore, the expression levels of these proteins were found to be modulated in response to pesticide and heavy metal stresses. Notably, overexpression of AccCDK2-like and AccCINP-like led to a noticeable alteration in E. coli 's ability to withstand external stresses. Additionally, silencing of the AccCDK2-like and AccCINP-like genes resulted in a significant reduction in antioxidant enzyme activity and the expression levels of genes related to antioxidant function. Consequently, the mortality rate of Apis cerana cerana under pesticide and heavy metal stresses conspicuously increased. Hence, our findings suggest that AccCDK2-like and AccCINP-like proteins potentially play a crucial role in the response of Apis cerana ceran a to pesticide and heavy metal stress, likely by modulating the antioxidant pathway. [Display omitted] • CDK2-like and CINP-like are involved in Apis cerana pesticide resistance. • CDK2-like and CINP-like are involved in Apis cerana heavy metal resistance. • CDK2-like and CINP-like take part in the Apis cerana 's oxidative stress response. [ABSTRACT FROM AUTHOR]

Y-box binding protein 1 (YB-1) is a member of the cold shock domain protein superfamily and is involved in development, environmental stresses and DNA oxidative damage in many organisms. However, the precise functions of YB-1 are still not well understood in various insects, including bees. In the current study, we identified a YB-1 gene in Apis cerana cerana ( AccYB-1 ). The predicted cis-acting elements in the promoter sequence of AccYB-1 indicated its possible roles in development and stress responses. AccYB-1 expression was higher in one-day-old larvae and dark-eyed pupae than in other development stages. Tissue-specific expression analysis showed that the mRNA level of AccYB-1 was higher in the thorax and midgut than in other tissues. The results from real-time PCR showed that AccYB-1 was induced by many environmental stresses. Silencing AccYB-1 downregulated the transcriptional level of some growth- and development-related genes and antioxidant genes and decreased the enzyme activities of several antioxidant-related enzymes, further indicating a possible function of AccYB-1 in growth, development and stress responses. Taken together, our findings suggest that AccYB-1 may play an indispensable role in growth and development and environmental stress responses in Apis cerana cerana . To our knowledge, this is the first paper to explore the role of YB-1 in bees. [ABSTRACT FROM AUTHOR]

Previous studies examining the functions of cyclin-dependent kinases (CDKs) have mainly focused on the regulation of the cell cycle. Recent studies have found that cyclin-dependent kinase 7 (CDK7) and cyclin-dependent kinase 9 (CDK9) play important roles in cell stress, metabolism of toxic substances and maintaining the stability of the internal environment. Here, we found that under stress conditions, the transcription and protein expression of AccCDK7 and AccCDK9 were induced to varying degrees. Meanwhile, the silencing of AccCDK7 and AccCDK9 also affected the expression of antioxidant genes and the activity of antioxidant enzymes, and reduced the survival rate of bees under high temperature stress. Furthermore, the exogenous overexpression of AccCDK7 and AccCDK9 improved the viability of yeast under stress conditions. Therefore, AccCDK7 and AccCDK9 may play roles in A.cerana cerana resistance to oxidative stress caused by external stimuli, potentially revealing a new mechanism of the honeybee response to oxidative stress. • Isolation of AccCDK7 and AccCDK9 from Apis cerana cerana. • The expression of AccCDK7 and AccCDK9 is induced by oxidative stress. • AccCDK7 and AccCDK9 can enhance the stress resistance of E. coli and yeast. • RNA interference experiments suggested that AccCDK7 and AccCDK9 is important for resistance against stresses. [ABSTRACT FROM AUTHOR]

Summary: Fusarium wilt is one of the most serious diseases affecting cotton. However, the pathogenesis and mechanism by which Fusarium oxysporum overcomes plant defence responses are unclear. Here, a new group D mitogen‐activated protein kinase (MAPK) gene, GhMPK20, was identified and functionally analysed in cotton. GhMPK20 expression was significantly induced by F. oxysporum. Virus‐induced gene silencing (VIGS) of GhMPK20 in cotton increased the tolerance to F. oxysporum, whereas ectopic GhMPK20 overexpression in Nicotiana benthamiana reduced F. oxysporum resistance via disruption of the salicylic acid (SA)‐mediated defence pathway. More importantly, an F. oxysporum‐induced MAPK cascade pathway composed of GhMKK4, GhMPK20 and GhWRKY40 was identified. VIGS of GhMKK4 and GhWRKY40 also enhanced F. oxysporum resistance in cotton, and the function of GhMKK4–GhMPK20 was shown to be essential for F. oxysporum‐induced GhWRKY40 expression. Together, our results indicate that the GhMKK4–GhMPK20–GhWRKY40 cascade in cotton plays an important role in the pathogenesis of F. oxysporum. This research broadens our knowledge of the negative role of the MAPK cascade in disease resistance in cotton and provides an important scientific basis for the formulation of Fusarium wilt prevention strategies. [ABSTRACT FROM AUTHOR]

Carboxylesterases (CarEs) play vital roles in metabolising different physiologically important endogenous compounds and in detoxifying various harmful exogenous compounds in insects. Multiple studies of CarEs have focused on pesticide metabolism in insects, while few studies have aimed to identify CarE functions in oxidative resistance, particularly in Apis cerana cerana . In this study, we isolated a carboxylesterase gene, esterase FE4, from Apis cerana cerana and designated it towards an exploration of its roles as an antioxidant and in detoxification. We investigated AcceFE4 expression patterns in response to various stressors. A quantitative real-time PCR analysis revealed that AcceFE4 was up-regulated by H 2 O 2 , imidacloprid, and paraquat, and was down-regulated by 4 °C, UV radiation, CdCl 2 , and HgCl 2 . Additionally, the protein expression of this gene was down-regulated at 4 °C and up-regulated by H 2 O 2 . Disc diffusion assays showed that the AcceFE4 recombinant protein-expressing bacteria had a smaller killing zone than the control group with the paraquat, HgCl 2 and cumyl hydroperoxide treatments. Moreover, when the gene was knocked down by RNA interference, we observed that multiple oxidant genes (i.e., AccSOD , AccGST , AccTrx , AccMsrA, and others) were down-regulated in the knockdown samples. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity levels were reduced in the knockdown samples relative to the control group. Finally, we measured the enzyme activity of carboxylesterase and found that the enzyme activity was also reduced in the silent samples. Together, these data suggest that AcceFE4 may be involved in the oxidative resistance response during adverse stress. [ABSTRACT FROM AUTHOR]

In eukaryotes, cytochrome c oxidase (COX) is a multimeric protein complex that is the last enzyme in the respiratory electron transport chain of mitochondria. Syntheses of cytochrome c oxidase (SCO) proteins are copper-donor chaperones involved in metalation of the CuA redox center of COX. However, its other precise actions are not yet understood. Here, we report the characterization of AccSCO2 from Apis cerana cerana ( Acc ). Our data showed that AccSCO2 expression was induced by cold (4 °C), CdCl 2 , HgCl 2 , ultraviolet (UV) light, and H 2 O 2 and was inhibited by different pesticide treatments. In addition, a disc diffusion assay of recombinant AccSCO2, AccSCO2-R1, and AccSCO2-R2 proteins showed that they played a functional role in protecting cells from oxidative stress involved in copper-dependent manner. Further, following knockdown of AccSCO2 in A. cerana cerana using RNA interference (RNAi), the expression levels of most antioxidant genes ( AccGSTD , AccGSTO1 , AccGSTS4 , AccSOD1 , AccSOD2 , etc.) were significantly decreased in the AccSCO2 -silenced bees compared with the control bees. Moreover, the antioxidant enzymatic activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were all lower in the silenced bees than in the control bees. Finally, the in vivo activity of COX was measured after AccSCO2 knockdown, which revealed a strong reduction in COX activity in the silenced bees. Thus, we hypothesize that AccSCO2 plays important roles in cellular stress responses and anti-oxidative processes, which help to regulate the production of mitochondrial reactive oxygen species and/or the impairment of mitochondrial activity under oxidative stress. [ABSTRACT FROM AUTHOR]

Vitellogenin (Vg) is a yolk precursor protein in most oviparous females. However, Vg has not been studied in the Apis cerana cerana. In this work, the Vg gene of the A. cerana cerana has been cloned and sequenced. The gene codes for a protein consisting of 1770 amino acids in seven exons with a predicted molecular mass and isoelectric point of 200 kDa and 6.46, respectively. Additionally, an 807-bp 5′-flanking region was isolated, and potential transcription factor binding sites associated with development and stress response were identified. Quantitative real-time PCR analysis showed that AccVg is highly expressed in pupae during different developmental stages. In addition, the expression of AccVg could be induced by cold (4 and 16 °C), CdCl, and pesticide treatment. Real-time quantitative PCR (RT-PCR) and western blot analyses indicated that AccVg transcription was induced by various abiotic stresses. Western blot was used to measure the expression levels of AccVg protein. Taken together, these results suggest that AccVg most likely plays essential roles in antioxidant defence and that it may be of critical importance to honey bee survival. [ABSTRACT FROM AUTHOR]

Insect cytochrome P450 monooxygenases (P450s or CYPs) perform important functions in the metabolic detoxification of both endogenous and exogenous substrates. However, the mechanism of action of the P450 genes in bees is unclear. In this study, we investigated the effects of AccCYP6k1 on the metabolism and detoxification of Apis cerana cerana. Spatiotemporal expression profiling revealed that the expression of AccCYP6k1 was the highest in foragers (A15) and was mainly expressed in the leg, midgut and head. RT–qPCR results showed that AccCYP6k1 exhibited different expression patterns following exposure to xenobiotics. In addition, silencing AccCYP6k1 increased the pesticides sensitivity and affected the detoxification system and antioxidant process of A. cerana cerana. In brief, the induced expression of AccCYP6k1 is related to the resistance of A. cerana cerana , while knockdown AccCYP6k1 affect the pesticides resistance and metabolic detoxification system of A. cerana cerana. These findings not only support the theoretical basis of metabolic detoxification in bees but also provide a better understanding of P450-mediated resistance to pesticides in insects. [Display omitted] • The level of inducible expression of AccCYP6k1 is related to pesticide resistance. • Silencing AccCYP6k1 increased the sensitivity of Apis cerana cerana to abamectin and imidacloprid. • Silencing AccCYP6k1 had adverse effects on the detoxification system of Apis cerana cerana. [ABSTRACT FROM AUTHOR]

Tyrosine aminotransferase (TATN) is the first enzyme involved in the metabolic degradation of tyrosine, and it plays an important role in tyrosine detoxification and helps the body resist oxidative damage. However, the function of TATN in Apis cerana cerana (A. c. cerana) remains unclear. To explore the role of TATN in the response to pesticide and heavy metal stress in A. c. cerana , AccTATN was isolated and identified. AccTATN was highly expressed in the integument and the adult stage. Exposure to multiple pesticides and heavy metal stress upregulated AccTATN expression. RNA interference experiments showed that silencing AccTATN reduced the resistance of A. c. cerana to glyphosate and avermectins stress. The expression of antioxidant-related genes and the activity of antioxidant enzymes were reduced after AccTATN was silenced, leading to the accumulation of oxidative damage. Overexpression of the recombinant AccTATN protein in a prokaryotic system also confirmed its role in heavy metal stress and improved antioxidant capacity. Our study showed that AccTATN may promote resistance to pesticide and heavy metal stress by regulating the antioxidant capacity of A. c. cerana. This study provides a valuable theoretical basis for A. c. cerana conservation. [Display omitted] • AccTATN gene was isolated and characterized from (A. c. cerana) • Pesticide and heavy metal stress can affect the expression of AccTATN. • AccTATN overexpression enhanced the tolerance of E. coli cells to oxidative stress. • AccTATN knockdown disrupted the original redox balance and caused oxidative stress. • AccTATN promotes A. c. cerana to resist pesticide and heavy metal stress. [ABSTRACT FROM AUTHOR]

Apis cerana cerana is a native bee species in China and plays a key role in agricultural production and ecological balance. However, the growth and development of Apis cerana cerana has not been smooth, and pesticide and heavy metal stress are key factors that have forced a dramatic decline in population size. This study was performed with the objective of investigating the role of AccCDK20 and AccCDKN1 in honey bee resistance to pesticide and heavy metal stress. RT–qPCR analysis revealed that AccCDK20 transcript levels were highest in brown-eyed pupae and AccCDKN1 transcript levels were highest in 1-day-old worker bees. In different tissues and body parts of adult bees, AccCDK20 transcript levels were highest in the head, and AccCDKN1 transcript levels were highest in the thorax. It was further observed that environmental stress can affect the transcript levels of the AccCDK20 and AccCDKN1 genes. Silencing of the AccCDK20 and AccCDKN1 genes resulted in altered activities of antioxidant-related genes and antioxidant-related enzymes. AccCDK20 and AccCDKN1 transcript levels were upregulated under glyphosate stress, and silencing of the genes resulted in reduced resistance to glyphosate and greatly increased mortality in Apis cerana cerana. In addition, gene function was verified by in vitro repression assays. Overexpression of the AccCDK20 and AccCDKN1 proteins in E. coli cells increased the resistance to ROS damage induced by CHP. In conclusion, AccCDK20 and AccCDKN1 play an indispensable role in honey bee resistance to pesticide and heavy metal stress. [Display omitted] • Silencing AccCDK20 and AccCDKN1 affects the oxidative system. • AccCDK20 and AccCDKN1 promote honey bee resistance to glyphosate stress. • Overexpression of AccCDK20 and AccCDKN1 enhances the antioxidant capacity of E. coli. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase kinase kinases (MAPKKKs) function at the top level of MAPK cascades and play important roles in plant development and stress responses. Although MAPKKKs comprise the largest family in the MAPK cascades, very few Raf-like MAPKKKs have been functionally identified, especially in the economically important crop cotton. In this study, a Raf-like MAPKKK gene, GhRaf19 , was characterized for the first time in cotton. Our data show that the expression of GhRaf19 was inhibited by PEG and NaCl and induced by cold (4 °C) and H 2 O 2 . Furthermore, when GhRaf19 was silenced in cotton using virus-induced gene silencing (VIGS), tolerance to drought and salt stress were enhanced, the accumulation of reactive oxygen species (ROS) was reduced, and ROS-related gene expression was increased. Consistent with these results, in N. benthamiana , overexpressing- GhRaf19 reduced tolerance to drought and salt. However, GhRaf19 -silenced plants showed lowered resistance to cold in cotton, and this effect was correlated with the accumulation of ROS. In contrast, overexpressing GhRaf19 in N. benthamiana increased resistance to cold by inducing higher levels of expression and activity of ROS-related antioxidant genes/enzymes. These results indicate that GhRaf19 negatively regulates tolerance to drought and salt and positively regulates resistance to cold stress by modulating cellular ROS in cotton. [ABSTRACT FROM AUTHOR]

Apis cerana cerana triosephosphate isomerase ( AccTPI), a key regulatory enzyme in glycolysis and gluconeogenesis pathway, catalyzes the interconversion of glyceraldehyde 3-phosphate to dihydroxyacetone phosphate. However, its role in A. cerana cerana has not been completely clarified. In this study, a TPI gene was cloned from A. cerana cerana and named AccTPI. The open reading frame (ORF) of AccTPI is 744 bp, which encodes 247 amino acids with a predicted molecular weight and an isoelectric point of 26.8 kDa and 8.42, respectively. The expression of AccTPI was up-regulated by some abiotic stresses, while it was down-regulated by HgCl, ultraviolet light (UV), and vitamin C (VC) treatment. Finally, a disc diffusion assay revealed that recombinant AccTPI proteins can protect cells from oxidative stresses. Taken together, all of the results indicate that AccTPI may play an important role in the metabolism, in antioxidant defense, and in many biological functions in the growth and development of A. cerana cerana. [ABSTRACT FROM AUTHOR]

Activating transcription factor 2 (ATF2), a basic leucine zipper (bZIP) transcription factor, plays a crucial role in immune and DNA damage response in mammals. However, the function of ATF2 in insects remains unknown. Here, we isolated the ATF2 gene from Apis cerana cerana (AccATF2) and found that AccATF2 was a main regulator of the honeybee response to oxidative stress. Our results showed that AccATF2 was highly expressed in the head, thorax and integument. AccATF2 was expressed throughout the development period of honeybees, and the highest AccATF2 transcript level was noted in brown-eyed pupae, indicating its indispensable roles in honeybee survival. Antioxidant function analysis showed that AccATF2 expression was markedly induced in response to oxidative stress caused by various environmental stresses. AccATF2 overexpression substantially enhanced the tolerance to oxidative stress of Escherichia coli cells compared with control cells. AccATF2 knockdown significantly increased the production of malondialdehyde (MDA), the transcription of antioxidant genes and the activity of antioxidant enzymes in honeybees, suggesting that AccATF2 knockdown resulted in oxidative damage to honeybees. Moreover, AccATF2 knockdown decreased honeybee resistance to oxidative stress caused by high temperature. Overall, AccATF2 plays an important role in maintaining redox homeostasis and protecting honeybees from oxidative stress caused by various environmental stimuli. Our discoveries add to a growing understanding of how honeybees cope with various adverse environmental conditions to ensure their survival. [Display omitted] • AccATF2 gene was isolated and characterized from Apis cerana cerana. • The expression of AccATF2 was induced by oxidative stress caused by adverse environment. • AccATF2 overexpression enhanced the tolerance of E. coli cells to oxidative stress. • AccATF2 knockdown disrupted the original redox balance and caused oxidative stress. [ABSTRACT FROM AUTHOR]

To tolerate many acute and chronic oxidative stress-producing agents that exist in the environment, organisms have evolved many classes of signal transduction pathways, including the transforming growth factor β (TGFβ) signal pathway. Decapentapletic gene (Dpp) belongs to the TGFβ superfamily, and studies on Dpp have mainly focused on its role in the regulation of development. No study has investigated the response of Dpp to oxidative pressure in any organism, including Apis cerana cerana (A. cerana cerana). In this study, we identified a Dpp gene from A. cerana cerana named AccDpp. The 5΄ flanking region of AccDpp had many transcription factor binding sites that relevant to development and stress response. AccDpp was expressed at all stages of A. cerana cerana, with its highest expression in 15-day worker bees. The mRNA level of AccDpp was higher in the poison gland and midgut than other tissues. Furthermore, the transcription of AccDpp could be repressed by 4°C and UV, but induced by other treatments, according to our qRT-PCR analysis. It is worth noting that the expression level of AccDpp protein was increased after a certain time when A. cerana cerana was subjected to all simulative oxidative stresses, a finding that was not completely consistent with the result from qRT-PCR. It is interesting that recombinant AccDpp restrained the growth of Escherichia coli, a function that might account for the role of the antimicrobial peptides of AccDpp. In conclusion, these results provide evidence that AccDpp might be implicated in the regulation of development and the response of oxidative pressure. The findings may lay a theoretical foundation for further genetic studies of Dpp. [ABSTRACT FROM AUTHOR]

WRKY transcription factors constitute a very large family of proteins in plants and participate in modulating plant biological processes, such as growth, development and stress responses. However, the exact roles of WRKY proteins are unclear, particularly in non-model plants. In this study, Gossypium hirsutum WRKY41 (GhWRKY41) was isolated and transformed into Nicotiana benthamiana. Our results showed that overexpression of GhWRKY41 enhanced the drought and salt stress tolerance of transgenic Nicotiana benthamiana. The transgenic plants exhibited lower malondialdehyde content and higher antioxidant enzyme activity, and the expression of antioxidant genes was upregulated in transgenic plants exposed to osmotic stress. A β-glucuronidase (GUS) staining assay showed that GhWRKY41 was highly expressed in the stomata when plants were exposed to osmotic stress, and plants overexpressing GhWRKY41 exhibited enhanced stomatal closure when they were exposed to osmotic stress. Taken together, our findings demonstrate that GhWRKY41 may enhance plant tolerance to stress by functioning as a positive regulator of stoma closure and by regulating reactive oxygen species (ROS) scavenging and the expression of antioxidant genes. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase (MAPK) cascades mediate various responses in plants. As the top component, MAP3Ks deserve more attention; however, little is known about the role of MAP3Ks, especially in cotton, a worldwide economic crop. In this study, a gene encoding a putative Raf-like MAP3K, GhMAP3K40, was isolated. GhMAP3K40 expression was induced by stress and multiple signal molecules. The plants overexpressing GhMAP3K40 had an enhanced tolerance to drought and salt stress at the germination stage. However, at the seedling stage, the transgenic plants suffered more severe damage after drought, exposure to pathogens and oxidative stress. The defence-related genes and the antioxidant system were activated in transgenic palnts, suggesting that GhMAP3K40 positively regulate the defence response. The transgenic plants were less able to prevent pathogenic invasion, which was due to defects in the cell structure of the leaves. The root system of the control plants were stronger compared with the transgenic plants. These results indicated a negative role of GhMAP3K40 in growth and development and GhMAP3K40 possibly caused the defects by down-regulating the lignin biosynthesis. Overall, these results suggest that GhMAP3K40 may positively regulate defence response but cause reduced tolerance to biotic and abiotic stress by negatively regulating growth and development. [ABSTRACT FROM AUTHOR]

4-Hydroxyphenylpyruvate dioxygenase (HPPD), a nonheme oxygenase, catalyzes the second step of the tyrosine catabolic pathway, which is shared by almost all aerobic life forms. This demonstrates its importance in aerobic biology. We isolated an HPPD homolog from Apis cerana cerana and named it AccHPPD. AccHPPD has an open reading frame (ORF) length of 900 bp and encodes a 299 amino acid protein that has a predicted molecular weight of 34.67 kDa and an isoelectric point of 6.27. Amino acid analysis showed that AccHPPD contained three conserved metal ion active sites, H-101, H-184 and E-267. Real-time fluorescence quantitative PCR (RT–qPCR) analysis showed that AccHPPD mainly existed in specific tissue sites, mainly high in the legs and in the thorax and epidermis, and in specific developmental stages, mainly adults. Under temperature, pesticide, heavy metal and ultraviolet (UV) radiation treatments, the expression level was downregulated, but under H 2 O 2 treatment, the expression level was upregulated. Exogenous expression of the recombinant AccHPPD plasmid in E. coli enhanced the resistance to HgCl 2 and H 2 O 2. Inhibition of AccHPPD activity was demonstrated by the upregulation of the tyrosine content after feeding with the inhibitor 2-(2-nitro-4-trifluoromethyl benzoyl)-1,3-cyclohexanedione (NTBC). After silencing of AccHPPD , the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) decreased, and the expression levels of AccBax- and AccCaspase8 -related genes were upregulated. The antioxidant genes AccCAT, AccGSTZ1, AccGSTD, AccSOD2, AccTpx3, AccCYP4G11, AccGDTS4, AccGSTO2 and AccMSRA were all upregulated. These results suggest that AccHPPD may serve an integral function in the response of A. cerana cerana to oxidative stress. [Display omitted] • AccHPPD enhances resistance to H 2 O 2. • NTBC inhibition has a time-limited effect. • Silencing of AccHPPD induces apoptotic genes. [ABSTRACT FROM AUTHOR]

The WRKY transcription factors modulate numerous physiological processes, including plant growth, development and responses to various environmental stresses. Currently, our understanding of the functions of the majority of the WRKY family members and their possible roles in signalling crosstalk is limited. In particular, very few WRKYs have been identified and characterised from an economically important crop, cotton. In this study, we characterised a novel group IIc WRKY gene, GhWRKY68, which is induced by different abiotic stresses and multiple defence-related signalling molecules. The β-glucuronidase activity driven by the GhWRKY68 promoter was enhanced after exposure to drought, salt, abscisic acid (ABA) and H2O2. The overexpression of GhWRKY68 in Nicotiana benthamiana reduced resistance to drought and salt and affected several physiological indices. GhWRKY68 may mediate salt and drought responses by modulating ABA content and enhancing the transcript levels of ABA-responsive genes. GhWRKY68-overexpressing plants exhibited reduced tolerance to oxidative stress after drought and salt stress treatments, which correlated with the accumulation of reactive oxygen species (ROS), reduced enzyme activities, elevated malondialdehyde (MDA) content and altered ROS-related gene expression. These results indicate that GhWRKY68 is a transcription factor that responds to drought and salt stresses by regulating ABA signalling and modulating cellular ROS. [ABSTRACT FROM AUTHOR]

Drought and high salinity are two major environmental factors that significantly limit the productivity of agricultural crops worldwide. WRKY transcription factors play essential roles in the adaptation of plants to abiotic stresses. However, WRKY genes involved in drought and salt tolerance in cotton (Gossypium hirsutum) are largely unknown. Here, a group IId WRKY gene, GhWRKY17, was isolated and characterized. GhWRKY17 was found to be induced after exposure to drought, salt, H2O2 and ABA. The constitutive expression of GhWRKY17 in Nicotiana benthamiana remarkably reduced plant tolerance to drought and salt stress, as determined through physiological analyses of the germination rate, root growth, survival rate, leaf water loss and Chl content. GhWRKY17 transgenic plants were observed to be more sensitive to ABA-mediated seed germination and root growth. However, overexpressing GhWRKY17 in N. benthamiana impaired ABA-induced stomatal closure. Furthermore, we found that GhWRKY17 modulated the increased sensitivity of plants to drought by reducing the level of ABA, and transcript levels of ABA-inducible genes, including AREB, DREB, NCED, ERD and LEA, were clearly repressed under drought and salt stress conditions. Consistent with the accumulation of reactive oxygen species (ROS), reduced proline contents and enzyme activities, elevated electrolyte leakage and malondialdehyde, and lower expression of ROS-scavenging genes, including APX, CAT and SOD, the GhWRKY17 transgenic plants exhibited reduced tolerance to oxidative stress compared with wild-type plants. These results therefore indicate that GhWRKY17 responds to drought and salt stress through ABA signaling and the regulation of cellular ROS production in plants. [ABSTRACT FROM AUTHOR]

Apoptosis-inducing factors (AIFs) play vital roles in bioenergetic and redox metabolism. Compared with studies focused on the apoptogenic function of AIF, few studies have reported on its oxidoreductase function, especially in insects. In this study, we identified a novel AIF gene AccAIF3 that was isolated from Apis cerana cerana, and investigated its expression and structural features. Quantitative real-time PCR (qRT-PCR) revealed the highest mRNA level of AccAIF3 in adult bees at 15 days. qRT-PCR results revealed that AccAIF3 transcripts were induced by cold, CdCl, HgCl, UV, pyriproxyfen and cyhalothrin, but were downregulated by ecdysone. We also compared the expression of AIF3 from Apis cerana cerana and Apis mellifera ligustica Spinola to Ascosphaera apis, and found that AIF3s may respond to Ascosphaera apis in a species-specific manner. These data suggested that AccAIF3 may play vital roles in the response to abiotic and biotic stresses and contribute to the adaptability of honeybees to adversities. [ABSTRACT FROM AUTHOR]

Small heat shock proteins (sHSPs) play an important role in protecting against stress-induced cell damage and fundamental physiological processes. In this study, we identified an intronless sHsp gene from Apis cerana cerana ( AccsHsp22.6 ). The open reading frame of AccsHsp22.6 was 585 bp and encoded a 194 amino acid protein. Furthermore, a 2064 bp 5'-flanking region was isolated, and potential transcription factor binding sites associated with development and stress response were identified. Quantitative PCR and western blot analyses demonstrated that AccsHsp22.6 was detected at higher levels in the midgut than in other tissues tested, and it is highly expressed during the shift to different development stages. Moreover, AccsHsp22.6 was significantly up-regulated by abiotic and biotic stresses, such as 4 °C, 16 °C, 42 °C, cyhalothrin, pyridaben, H 2 O 2 , UV, CdCl 2 , 20-hydroxyecdysone and Ascosphaera apis treatments. However, AccsHsp22.6 was slightly repressed by other stresses, including 25 °C, phoxim, paraquat and HgCl 2 treatments. The recombinant AccsHSP22.6 also exhibited significant temperature tolerance, antioxidation and molecular chaperone activity. In addition, we found that knockdown of AccsHsp22.6 by RNA interference remarkably reduced temperature tolerance in A . cerana cerana . Taken together, these results suggest that AccsHsp22.6 plays an essential role in the development stages and defence against cellular stress. [ABSTRACT FROM AUTHOR]

The cyclin-dependent kinase (CDK) protein family plays an important role in regulating life functions, such as the cell cycle and metabolism. This study reports the first cloning and functional analysis of A. cerana cerana CDK1 (AccCDK1). The distribution profile of AccCDK1 in different developmental periods and different tissues was determined. The experimental results showed that the distribution of AccCDK1 was tissue-specific. AccCDK1 distribution at the transcriptional and translational levels was affected by stress conditions induced by H 2 O 2 , UV, HgCl 2 , CdCl 2 , extreme temperatures (4 °C, 44 °C) and pesticides (avermectin, lambda-cyhalothrin, haloxyfop- R -methyl, and glyphosate), which resulted in changes in the expression levels. These results suggest that AccCDK1 may have an important part to play in honey bee resistance to stress. The expression of a recombinant AccCDK1 protein in vitro enhanced the antistress capacities of E. coli and yeast, which suggests that AccCDK1 is related to the stress response. When AccCDK1 was silenced, the expression of some antioxidant genes was downregulated, and the enzymatic potencies of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were reduced, which suggests that AccCDK1 takes part in the body's resistance to oxidative stress upon external stimulation by influencing relevant antioxidants. Notably, the survival rate of A. cerana cerana under high-temperature-induced stress decreased after AccCDK1 silencing, which verifies our results. In conclusion, we found that AccCDK1 played an indispensable function in resisting oxidative stress and maintaining normal cellular functions. [Display omitted] • Oxidative stress can affect the expression of cyclin-dependent kinase1. • AccCDK1 silencing affects cellular antioxidant genes and enzymes. • AccCDK1 promotes the survival of eukaryotic and prokaryotic cells under stress. • AccCDK1 promotes bees to resist high temperature stress. [ABSTRACT FROM AUTHOR]

The plant mitogen-activated protein kinase (MAPK) cascade plays an important role in mediating responses to biotic and abiotic stresses and is the main pathway through which extracellular stimuli are transduced intracellularly as signals. Our previous research showed that the GhMKK6-GhMPK4 cascade signaling pathway plays an important role in cotton immunity. To further analyze the role and regulatory mechanism of the GhMKK6-GhMPK4 cascade signaling pathway in cotton resistance to Fusarium wilt, we functionally analyzed GhMPK4. Our results show that silencing GhMPK4 reduces cotton tolerance to Fusarium wilt and reduces the expression of several resistance genes. Further experiments revealed that GhMPK4 is similar to GhMKK6, both of whose overexpression cause unfavorable cotton immune response characteristics. By using a yeast two-hybrid screening library and performing a bioinformatics analysis, we screened and identified a negative regulator of the MAPK kinase-protein phosphatase AP2C1. Through the functional analysis of AP2C1, it was found that, after being silenced, GhAP2C1 increased resistance to Fusarium wilt, but GhAP2C1 overexpression caused sensitivity to Fusarium wilt. These findings show that GhAP2C1 interacts together with GhMPK4 to regulate the immune response of cotton to Fusarium oxysporum, which provides important data for functionally analyzing and studying the feedback regulatory mechanism of the MAPK cascade and helps to clarify the regulatory mechanism through which the MAPK cascade acts in response to pathogens. [ABSTRACT FROM AUTHOR]

Honeybees show an important pollination ability and play vital roles in improving crop yields and increasing plant genetic diversity, thereby generating tremendous economic benefits for humans. However, honeybee survival is affected by a number of biological and abiotic stresses, including the effects of fungi, bacteria, viruses, parasites, and especially agrochemicals. Glyphosate, a broad-spectrum herbicide that is primarily used for weed control in agriculture, has been reported to have lethal and sublethal effects on honeybees. Here, we summarize recent advances in research on the effects of glyphosate on honeybees, including effects on their behaviors, growth and development, metabolic processes, and immune defense, providing a detailed reference for studying the mechanism of action of pesticides. Furthermore, we provide possible directions for future research on glyphosate toxicity to honeybees. [ABSTRACT FROM AUTHOR]

Abstract: Thioredoxin peroxidases (Tpxs), members of the antioxidant protein family, play critical roles in resisting oxidative stress. In this work, a novel 1-Cys thioredoxin peroxidase gene was isolated from Apis cerana cerana and was named AccTpx5. The open reading frame (ORF) of AccTpx5 is 663bp in length and encodes a 220-amino acid protein with a predicted molecular mass and isoelectric point of 24,921kDa and 5.45, respectively. Promoter sequence analysis of AccTpx5 revealed the presence of putative transcription factor binding sites related to early development and stress responses. Additionally, real-time quantitative PCR (Q-PCR) analysis indicated that AccTpx5 was primarily present in some developmental stages, with the highest expression levels in the first-instar larvae. The expression level of AccTpx5 was up-regulated under various abiotic stresses, including 4°C, 42°C, HgCl2, H2O2, phoxim and acaricide treatments. Conversely, it was down-regulated by UV and pyriproxyfen treatments. Moreover, H2O2 concentration dramatically increased under a variety of stressful conditions. Finally, the purified recombinant AccTpx5 protein protected the supercoiled form of plasmid DNA from damage in the thiol-dependent mixed-function oxidation (MFO) system. These results suggest that AccTpx5 most likely plays an essential role in antioxidant defence. [Copyright &y& Elsevier]

WRKY transcription factors form one of the largest transcription factor families and function as important components in the complex signaling processes that occur during plant stress responses. However, relative to the research progress in model plants, far less information is available on the function of WRKY proteins in cotton. In the present study, we identified the GhWRKY40 gene in cotton (Gossypium hirsutum) and determined that the GhWRKY40 protein is targeted to the nucleus and is a stress-inducible transcription factor. The GhWRKY40 transcript level was increased upon wounding and infection with the bacterial pathogen Ralstonia solanacearum. The overexpression of GhWRKY40 down-regulated most of the defense-related genes, enhanced the wounding tolerance and increased the susceptibility to R. solanacearum. Consistent with a role in multiple stress responses, we found that the GhWRKY40 transcript level was increased by the stress hormones salicylic acid (SA), methyl jasmonate (MeJA) and ethylene (ET). Moreover, GhWRKY40 interacted with the MAPK kinase GhMPK20, as shown using yeast two-hybrid and bimolecular fluorescence complementation systems. Collectively, these results suggest that GhWRKY40 is regulated by SA, MeJA and ET signaling and coordinates responses to wounding and R. solanacearum attack. These findings highlight the importance of WRKYs in regulating wounding- and pathogen-induced responses. [ABSTRACT FROM AUTHOR]

Key message: Our results indicate that overexpression of the GhWRKY39 - 1 gene enhances resistance to pathogen infection and tolerance to high salt and oxidative stress in transgenic Nicotiana benthamiana. Abstract: WRKY transcription factor genes play significant roles in the response to biotic and abiotic stresses. Cotton ( Gossypium hirsutum) is an important fiber and oil crop worldwide. We isolated and characterized GhWRKY39- 1, which is a group IId WRKY gene that is present as a single copy in the cotton genome. Quantitative PCR analyses indicated that GhWRKY39- 1 was induced by pathogen infection, defense-related signaling molecules, and abiotic stresses, such as NaCl and methyl viologen. An analysis of the subcellular localization of the GhWRKY39-1 protein indicated that it localized to the nucleus. Furthermore, constitutive overexpression of GhWRKY39- 1 in Nicotiana benthamiana conferred a greater resistance to infection by both the bacterial pathogen Ralstonia solanacearum and the fungal pathogen Rhizoctonia solani. The transgenic plants also exhibited elevated mRNA levels of several pathogen-related ( PR) genes, including PR1c, PR2 and PR4. Moreover, transgenic plants displayed an enhanced tolerance to salt and oxidative stress and elevated expression of several oxidation-related genes, including APX, CAT, GST and SOD. Overall, these results indicate that GhWRKY39- 1 functions as a positive regulator of plant defense against pathogen infection and responses to salt stress and reactive oxygen species. [ABSTRACT FROM AUTHOR]