Isolation of the AccCDK8 gene of Apis cerana cerana and its functional analysis under pesticide and heavy metal stress.

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.

The gene AccCyclin H mitigates oxidative stress by influencing trehalose metabolism in Apis cerana cerana.

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.

Toxic effects of the heavy metal Cd on Apis cerana cerana (Hymenoptera: Apidae): Oxidative stress, immune disorders and disturbance of gut microbiota.

Cadmium (Cd) is a toxic non-essential metal element that can enter the honey bee body through air, water and soil. Currently, there is a lack of sufficient research on the effects of Cd on A. cerana cerana, especially the potential risks of long-term exposure to sublethal concentrations. In order to ascertain the toxicological effects of the heavy metal Cd on bees, we performed laboratory-based toxicity experiments on worker bees and conducted analyses from three distinctive facets: antioxidative, immunological, and gut microbiota. The results showed that exposure of bees to high concentrations of Cd resulted in acute mortality, and the increase in mortality was concentration dependent. In long-term exposure to sublethal concentrations, Cd reduced the number of transcripts of antioxidant genes (AccSOD1, AccTPx3 and AccTPx4) and superoxide dismutase activity, causing an increase in malondialdehyde content. Simultaneously, the transcription of immune-related genes (AccAbaecin and AccApidaecin) and acetylcholinesterase activities was inhibited. Furthermore, Cd changes the structural characteristics of bacterial and fungal communities in the gut, disrupting the balance of microbial communities. In conclusion, the health and survival of honey bees are affected by Cd. This study provides a scientific basis for investigating the toxicological mechanisms and control strategies of the heavy metal Cd on honey bees, while facilitating a better understanding and protection of these valuable honey bees.

Ceria-Based Nanozymes in Point-of-Care Diagnosis: An Emerging Futuristic Approach for Biosensing.

In recent years, there has been a notable increase in interest surrounding nanozymes due to their ability to imitate the functions and address the limitations of natural enzymes. The scientific community has been greatly intrigued by the study of nanoceria, primarily because of their distinctive physicochemical characteristics, which include a variety of enzyme-like activities, affordability, exceptional stability, and the ability to easily modify their surfaces. Consequently, nanoceria have found extensive use in various biosensing applications. However, the impact of its redox activity on the enzymatic catalytic mechanism remains a subject of debate, as conflicting findings in the literature have presented both pro-oxidant and antioxidant effects. Herein, we creatively propose a seesaw model to clarify the regulatory mechanism on redox balance and survey possible mechanisms of multienzyme mimetic properties of nanoceria. In addition, this review aims to showcase the latest advancements in this field by systematically discussing over 180 research articles elucidating the significance of ceria-based nanozymes in enhancing, downsizing, and enhancing the efficacy of point-of-care (POC) diagnostics. These advancements align with the ASSURED criteria established by the World Health Organization (WHO). Furthermore, this review also examines potential constraints in order to offer readers a concise overview of the emerging role of nanoceria in the advancement of POC diagnostic systems for future biosensing applications.

Functional analysis of AccCDK2-like and AccCINP-like genes in Apis cerana cerana under pesticide and heavy metal stress.

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 cerana to pesticide and heavy metal stress, likely by modulating the antioxidant pathway.

Angiogenesis modulated by CD93 and its natural ligands IGFBP7 and MMRN2: a new target to facilitate solid tumor therapy by vasculature normalization.

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.

Nitrile-Specific Protein NSP2 and Its Interacting Protein MPK3 Synergistically Regulate Plant Disease Resistance in Arabidopsis.

Glucosinolates and their degradation products have a wide range of actions and are important components of plant defense. NSP2 (nitrile-specific protein 2) is a key regulator in the breakdown process of glucosinolates. However, the precise function of NSP2 in plant disease resistance beyond its role in glucosinolate degradation is still unclear. In this study, we discovered that NSP2 which was induced by Pst DC3000, influenced PR genes expression and reactive oxygen burst. Additionally, omics analysis revealed that NSP2 was engaged in plant-pathogen interaction and several hormone signal transduction pathways. Furthermore, immunoprecipitation-tandem mass spectrometry analysis (IP-MS), bimolecular fluorescence complementation (BiFC), and co-immunoprecipitation demonstrated that NSP2 interacts with MPK3. Genetic analysis shows that NSP2 may be a function downstream of MPK3. Upon pathogen inoculation, NSP2 protein levels increase while MPK3 protein levels decrease. Moreover, the level of phosphorylated NSP2 decreases. Taken together, this study sheds light on a new mode of synergistic action between NSP2 and MPK3 in the disease resistance process.

Intronic microRNA-directed regulation of mitochondrial reactive oxygen species enhances plant stress tolerance in Arabidopsis.

MicroRNAs (miRNAs) play crucial roles in regulating plant development and stress responses. However, the functions and mechanism of intronic miRNAs in plants are poorly understood. This study reports a stress-responsive RNA splicing mechanism for intronic miR400 production, whereby miR400 modulates reactive oxygen species (ROS) accumulation and improves plant tolerance by downregulating its target expression. To monitor the intron splicing events, we used an intronic miR400 splicing-dependent luciferase transgenic line. Luciferase activity was observed to decrease after high cadmium concentration treatment due to the retention of the miR400-containing intron, which inhibited the production of mature miR400. Furthermore, we demonstrated that under Cd treatments, Pentatricopeptide Repeat Protein 1 (PPR1), the target of miR400, acts as a positive regulator by inducing ROS accumulation. Ppr1 mutation affected the Complex III activity in the electron transport chain and RNA editing of the mitochondrial gene ccmB. This study illustrates intron splicing as a key step in intronic miR400 production and highlights the function of intronic miRNAs as a 'signal transducer' in enhancing plant stress tolerance.

CRISPR/Cas9 gene editing technology: a precise and efficient tool for crop quality improvement.

MAIN CONCLUSION: This review provides a direction for crop quality improvement and ideas for further research on the application of CRISPR/Cas9 gene editing technology for crop improvement. Various important crops, such as wheat, rice, soybean and tomato, are among the main sources of food and energy for humans. Breeders have long attempted to improve crop yield and quality through traditional breeding methods such as crossbreeding. However, crop breeding progress has been slow due to the limitations of traditional breeding methods. In recent years, clustered regularly spaced short palindromic repeat (CRISPR)/Cas9 gene editing technology has been continuously developed. And with the refinement of crop genome data, CRISPR/Cas9 technology has enabled significant breakthroughs in editing specific genes of crops due to its accuracy and efficiency. Precise editing of certain key genes in crops by means of CRISPR/Cas9 technology has improved crop quality and yield and has become a popular strategy for many breeders to focus on and adopt. In this paper, the present status and achievements of CRISPR/Cas9 gene technology as applied to the improvement of quality in several crops are reviewed. In addition, the shortcomings, challenges and development prospects of CRISPR/Cas9 gene editing technology are discussed.

Fox transcription factor AccGRF1 in response to glyphosate stress in Apis cerana cerana.

Glyphosate is an herbicide commonly used in agriculture, and its widespread use has adversely affected the survival of nontarget organisms. Among these organisms, bees in particular are important pollinators, and declining bee populations have severely affected crop yields around the world. However, the molecular mechanism by which glyphosate harms bees remains unclear. In our experiment, we screened and cloned a glyphosate-induced gene in Apis cerana cerana (A. c. cerana) and named glyphosate response factor 1 (AccGRF1). Sequence analysis showed that AccGRF1 contains a winged-helix DNA binding domain, which suggests that it belongs to the Forkhead box (Fox) protein family. qRT-PCR and heterologous expression in Escherichia coli and yeast showed that AccGRF1 can respond to glyphosate and oxidative stress. After AccGRF1 knockdown by means of RNA interference (RNAi), the resistance of A. c. cerana to glyphosate stress improved. The results suggested that AccGRF1 is involved in A. c. cerana glyphosate stress tolerance. This study reveals the functions of Fox transcription factors in response to glyphosate stress and provides molecular insights into the regulation of glyphosate responses in honeybees.

Identification of the AccCDK7 and AccCDK9 genes and their involvement in the response to resist external stress in Apis cerana cerana.

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.

AccsHSP21.7 enhances the antioxidant capacity of Apis cerana cerana.

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.

Role of the tyrosine aminotransferase AccTATN gene in the response to pesticide and heavy metal stress in Apis cerana cerana.

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.

RNAi-mediated silencing of AccCYP6k1 revealed its role in the metabolic detoxification of Apis cerana cerana.

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.

Multi-omics profiling and digital image analysis reveal the potential prognostic and immunotherapeutic properties of CD93 in stomach adenocarcinoma.

Background: Recent evidence highlights the fact that immunotherapy has significantly improved patient outcomes. CD93, as a type I transmembrane glycoprotein, was correlated with tumor-associated angiogenesis; however, how CD93 correlates with immunotherapy in stomach adenocarcinoma (STAD) remains unclear. Methods: TCGA, GTEx, GEO, TIMER2.0, HPA, TISIDB, TCIA, cBioPortal, LinkedOmics, and ImmuCellAI public databases were used to elucidate CD93 in STAD. Visualization and statistical analysis of data were performed by R (Version 4.1.3), GraphPad (Version 8.0.1), and QuPath (Version 0.3.2). Results: CD93 was highly expressed in STAD compared with adjacent normal tissues. The overexpression of CD93 was significantly correlated with a poor prognosis in STAD. There was a negative correlation between CD93 expression levels with CD93 mutation and methylation in STAD. Our results revealed that CD93 expression was positively associated with most immunosuppressive genes (including PD-1, PD-L1, CTLA-4, and LAG3), immunostimulatory genes, HLA, chemokine, and chemokine receptor proteins in STAD. Furthermore, in STAD, CD93 was noticeably associated with the abundance of multiple immune cell infiltration levels. Functional HALLMARK and KEGG term enhancement analysis of CD93 through Gene Set Enrichment Analysis was correlated with the process of the angiogenesis pathway. Subsequently, digital image analysis results by QuPath revealed that the properties of CD93+ cells were statistically significant in different regions of stomach cancer and normal stomach tissue. Finally, we utilized external databases, including GEO, TISIDB, ImmuCellAI, and TCIA, to validate that CD93 plays a key role in the immunotherapy of STAD. Conclusion: Our study reveals that CD93 is a potential oncogene and is an indicative biomarker of a worse prognosis and exerts its immunomodulatory properties and potential possibilities for immunotherapy in STAD.

The role of AccCDK20 and AccCDKN1 from Apis cerana cerana in development and response to pesticide and heavy metal toxicity.

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.

Activating transcription factor 2 (AccATF2) regulates tolerance to oxidative stress in Apis cerana cerana.

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.

Identification and antioxidant capacity of 4-hydroxyphenylpyruvate dioxygenase (HPPD), a new favored herbicide target, in Apis cerana cerana.

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 H2O2 treatment, the expression level was upregulated. Exogenous expression of the recombinant AccHPPD plasmid in E. coli enhanced the resistance to HgCl2 and H2O2. 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.

Group IIc WRKY transcription factors regulate cotton resistance to Fusarium oxysporum by promoting GhMKK2-mediated flavonoid biosynthesis.

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.

Identification of the cuticle protein AccCPR2 gene in Apis cerana cerana and its response to environmental stress.

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.