1
|
Hu Y, Tian C, Feng Y, Ma W, Zhang Y, Yang Q, Zhang X. Transgenic early japonica rice: Integration and expression characterization of stem borer resistance Bt gene. Gene 2024; 927:148753. [PMID: 38972556 DOI: 10.1016/j.gene.2024.148753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/22/2024] [Accepted: 07/04/2024] [Indexed: 07/09/2024]
Abstract
BACKGROUND Transgenic insect-resistant rice offers an environmentally friendly approach to mitigate yield losses caused by lepidopteran pests, such as stem borers. Bt (Bacillus thuringiensis) genes encode insecticidal proteins and are widely used to confer insect resistance to genetically modified crops. This study investigated the integration, inheritance, and expression characteristics of codon-optimised synthetic Bt genes, cry1C* and cry2A*, in transgenic early japonica rice lines. METHODS The early japonica rice cultivar, Songgeng 9 (Oryza sativa), was transformed with cry1C* or cry2A*, which are driven by the ubi promoter via Agrobacterium tumefaciens-mediated transformation. Molecular analyses, including quantitative PCR (qPCR), enzyme-linked immunosorbent assay (ELISA), and Southern blot analysis were performed to confirm transgene integration, inheritance, transcriptional levels, and protein expression patterns across different tissues and developmental stages. RESULTS Stable transgenic early japonica lines exhibiting single-copy transgene integration were established. Transcriptional analysis revealed variations in Bt gene expression among lines, tissues, and growth stages, with higher expression levels observed in leaves than in other organs. Notably, cry2A* exhibited consistently higher mRNA and protein levels than cry1C* across all examined tissues and developmental time points. Bt protein accumulation followed the trend of leaves > stem sheaths > young panicles > brown rice, with peak expression during the filling stage in the vegetative tissues. CONCLUSIONS Synthetic cry2A* displayed markedly elevated transcription and translation compared to cry1C* in the transgenic early japonica rice lines examined. Distinct spatiotemporal patterns of Bt gene expression were elucidated, providing insights into the potential insect resistance conferred by these genes in rice. These findings will contribute to the development of insect-resistant japonica rice varieties and facilitate the rational deployment of Bt crops.
Collapse
Affiliation(s)
- Yueting Hu
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China.
| | - Chongbing Tian
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China
| | - Yanjiang Feng
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China
| | - Wendong Ma
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China
| | - Yunjiang Zhang
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China
| | - Qing Yang
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China
| | - Xirui Zhang
- Rice Research Institute, Heilongjiang Academy of Agricultural Sciences, Jiamusi 154026, China
| |
Collapse
|
2
|
Wang S, Guo Y, Sun Y, Weng M, Liao Q, Qiu R, Zou S, Wu S. Identification of two Bacillus thuringiensis Cry3Aa toxin-binding aminopeptidase N from Rhynchophorus ferrugineus (Coleoptera: Curculionidae). BULLETIN OF ENTOMOLOGICAL RESEARCH 2023; 113:615-625. [PMID: 37466033 DOI: 10.1017/s0007485323000299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Rhynchophorus ferrugineus is a quarantine pest that mainly damages plants in tropical regions, which are essential economic resources. Cry3Aa has been used to control coleopteran pests and is known to be toxic to R. ferrugineus. The binding of the Cry toxin to specific receptors on the target insect plays a crucial role in the toxicological mechanism of Cry toxins. However, in the case of R. ferrugineus, the nature and identity of the receptor proteins involved remain unknown. In the present study, pull-down assays and mass spectrometry were used to identify two proteins of aminopeptidase N proteins (RfAPN2a and RfAPN2b) in the larval midguts of R. ferrugineus. Cry3Aa was able to bind to RfAPN2a (Kd = 108.5 nM) and RfAPN2b (Kd = 68.2 nM), as well as midgut brush border membrane vesicles (Kd = 482.5 nM). In silico analysis of both RfAPN proteins included the signal peptide and anchored sites for glycosyl phosphatidyl inositol. In addition, RfAPN2a and RfAPN2b were expressed in the human embryonic kidney 293T cell line, and cytotoxicity assays showed that the transgenic cells were not susceptible to activated Cry3Aa. Our results show that RfAPN2a and RfAPN2b are Cry3Aa-binding proteins involved in the Cry3Aa toxicity of R. ferrugineus. This study deepens our understanding of the action mechanism of Cry3Aa in R. ferrugineus larvae.
Collapse
Affiliation(s)
- Shaozhen Wang
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yajie Guo
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- Asian Research Center for Bioresource and Environmental Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 188-0002, Japan
| | - Yunzhu Sun
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China
| | - Mingqing Weng
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China
| | - Qiliao Liao
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
| | - Ru Qiu
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
| | - Shuangquan Zou
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
| | - Songqing Wu
- College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, China, 350002
| |
Collapse
|
3
|
Wang C, Deng Z, Yuan J, Xu K, Sha L, Guan X, Huang Z, Shao E. Removal of an Aminopeptidase N From Midgut Brush Border Does Not Affect Susceptibility of Spodoptera litura (Lepidoptera: Noctuidae) Larvae to Four Insecticidal Proteins of Bacillus thuringiensis (Bacillales: Bacillaceae). JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:223-232. [PMID: 36421056 DOI: 10.1093/jee/toac184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Spodoptera litura is one of the most destructive lepidopteran insects of cabbages and cauliflowers in the world. Cry1 and Vip3 toxins from Bacillus thuringiensis have been reported to show toxicity in multiple lepidopteran insects. Binding of toxic molecules to specific receptors on the midgut epithelial cells is known to be a key step in the action mode of Bt toxins. Aminopeptidase N (APN) -like proteins have been reported to be binding sites of multiple Cry toxins in the midgut of Cry susceptible insects. In the present study, we identified six midgut APNs by analysis of the genome and midgut transcriptome of S. litura. CRISPR/Cas9 mediated gene-knockout system was utilized to mutate the GPI-anchor signal peptide at the C terminus of SlAPN1. SlAPN1 was verified to be removed from the midgut brush border membrane vesicles of a homozygous knockout strain of S. litura (SlAPN1-KO). Bioassay results indicated that susceptibility of the SlAPN1-KO strain to Cry1Aa, Cry1Ac, Cry1Ca, and Vip3Aa toxins was close to that of the wild-type strain of S. litura. RT-qPCR results showed that the transcriptional level of SlAPN2-6 was not up-regulated after knockout of the SlAPN1. Results in this study indicated that the SlAPN1 did not play a critical role in the pathway of toxicity of Cry1Aa, Cry1Ac, Cry1Ca, and Vip3Aa toxins in S. litura.
Collapse
Affiliation(s)
- Can Wang
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Zhimin Deng
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Jin Yuan
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Kexin Xu
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Li Sha
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Zhipeng Huang
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Ensi Shao
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| |
Collapse
|
4
|
Li Q, Li M, Zhu M, Zhong J, Wen L, Zhang J, Zhang R, Gao Q, Yu XQ, Lu Y. Genome-wide identification and comparative analysis of Cry toxin receptor families in 7 insect species with a focus on Spodoptera litura. INSECT SCIENCE 2022; 29:783-800. [PMID: 34405540 DOI: 10.1111/1744-7917.12961] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/30/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Cadherin, aminopeptidase N (APN) and alkaline phosphatase (ALP) have been characterized as Cry receptors. In this study, comparative genomic analysis of the 3 receptor families was performed in 7 insects. ALPs and APNs are divided into three and eight clades in phylogenetic trees, respectively. ALPs in clade 3 and APNs in clade 1 contain multiple paralogs within each species and most paralogs are located closely in chromosomes. Drosophila melanogaster has expanded APNs in clade 5 and were lowly expressed in midgut. Cadherins are divided into 16 clades; they may diverge before holometabolous insect speciation except for BtR and Cad89D-like clades. Eight insects from different orders containing BtR orthologs are sensitive to Cry1A or Cry3A, while five species without BtR are insensitive to both toxins. Most APNs in clade 1, several ALPs in clade 3, BtR and Cad89D-like genes were highly or moderately expressed in larval midgut of Spodoptera litura and the other six species, and several members in these clades have been identified as Cry receptors. Expressions of putative S. litura Cry receptors in the midgut after exposing to Bt toxins were also analyzed.
Collapse
Affiliation(s)
- Qilin Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Mengge Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Mengyao Zhu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Jielai Zhong
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Liang Wen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Jie Zhang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Ruonan Zhang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Qiang Gao
- College of Biology, Hunan University, Changsha, 410082, China
| | - Xiao-Qiang Yu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Yuzhen Lu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| |
Collapse
|
5
|
Shao E, Lin L, Liu S, Zhang J, Chen X, Sha L, Huang Z, Huang B, Guan X. Analysis of Homologs of Cry-toxin Receptor-Related Proteins in the Midgut of a Non-Bt Target, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2018; 18:4839024. [PMID: 29415259 PMCID: PMC5804751 DOI: 10.1093/jisesa/iex102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Indexed: 05/13/2023]
Abstract
The brown planthopper (BPH) Nilaparvata lugens is one of the most destructive insect pests in the rice fields of Asia. Like other hemipteran insects, BPH is not susceptible to Cry toxins of Bacillus thuringiensis (Bt) or transgenic rice carrying Bt cry genes. Lack of Cry receptors in the midgut is one of the main reasons that BPH is not susceptible to the Cry toxins. The main Cry-binding proteins (CBPs) of the susceptible insects are cadherin, aminopeptidase N (APN), and alkaline phosphatase (ALP). In this study, we analyzed and validated de novo assembled transcripts from transcriptome sequencing data of BPH to identify and characterize homologs of cadherin, APN, and ALP. We then compared the cadherin-, APN-, and ALP-like proteins of BPH to previously reported CBPs to identify their homologs in BPH. The sequence analysis revealed that at least one cadherin, one APN, and two ALPs of BPH contained homologous functional domains identified from the Cry-binding cadherin, APN, and ALP, respectively. Quantitative real-time polymerase chain reaction used to verify the expression level of each putative Cry receptor homolog in the BPH midgut indicated that the CBPs homologous APN and ALP were expressed at high or medium-high levels while the cadherin was expressed at a low level. These results suggest that homologs of CBPs exist in the midgut of BPH. However, differences in key motifs of CBPs, which are functional in interacting with Cry toxins, may be responsible for insusceptibility of BPH to Cry toxins.
Collapse
Affiliation(s)
- Ensi Shao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
- China National Engineering Research Center of JUNCAO Technology, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Li Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Sijun Liu
- Department of Entomology, Iowa State University, Ames, IA, 50011
| | - Jiao Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Xuelin Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Li Sha
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Zhipeng Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Biwang Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, School of Life Science, Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, PR China
| |
Collapse
|
6
|
Zhao M, Yuan X, Wei J, Zhang W, Wang B, Myint Khaing M, Liang G. Functional roles of cadherin, aminopeptidase-N and alkaline phosphatase from Helicoverpa armigera (Hübner) in the action mechanism of Bacillus thuringiensis Cry2Aa. Sci Rep 2017; 7:46555. [PMID: 28488696 PMCID: PMC5424343 DOI: 10.1038/srep46555] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/17/2017] [Indexed: 11/08/2022] Open
Abstract
A pyramid strategy combining the Cry1A and Cry2A toxins in Bt crops has been widely used throughout the world to delay pest adaption to transgenic crops and broaden the insecticidal spectrum. Midgut membrane-bound cadherin (CAD), aminopeptidase-N (APN) and alkaline phosphatase (ALP) are important for Cry1A toxicity in some lepidopteran larvae, but the proteins that bind Cry2A in the midgut of target insects and their role in the Cry2A mechanism of action are still unclear. In this study, we found that heterologously expressed CAD, APN4 and ALP2 peptides from the midgut of Helicoverpa armigera could bind to the Cry2Aa toxin with a high affinity. Additionally, the efficiency of Cry2Aa insecticidal activity against H. armigera larvae was obviously reduced after the genes encoding these proteins were silenced with specific siRNAs: CAD- and ALP2-silenced larvae showed significantly similar reductions in mortality due to the Cry2Aa toxin (41.67% and 43.06%, respectively), whereas a larger reduction in mortality was observed in APN4-silenced larvae (61.11%) than in controls. These results suggest that CAD, APN4 and ALP2 are involved in the mechanism of action of Cry2Aa in H. armigera and may play important functional roles in the toxicity of the Cry2Aa toxin.
Collapse
Affiliation(s)
- Man Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiangdong Yuan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jizhen Wei
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wanna Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bingjie Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Myint Myint Khaing
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Gemei Liang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| |
Collapse
|
7
|
Gong L, Wang H, Qi J, Han L, Hu M, Jurat-Fuentes JL. Homologs to Cry toxin receptor genes in a de novo transcriptome and their altered expression in resistant Spodoptera litura larvae. J Invertebr Pathol 2015; 129:1-6. [PMID: 25981133 DOI: 10.1016/j.jip.2015.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 05/04/2015] [Accepted: 05/08/2015] [Indexed: 10/23/2022]
Abstract
Insect resistance threatens sustainability of insecticides based on Cry proteins from the bacterium Bacillus thuringiensis (Bt). Since high levels of resistance to Cry proteins involve alterations in Cry-binding midgut receptors, their identification is needed to develop resistance management strategies. Through Illumina sequencing we generated a transcriptome containing 16,161 annotated unigenes for the Oriental leafworm (Spodoptera litura). Transcriptome mining identified 6 contigs with identity to reported lepidopteran Cry toxin receptors. Using PCR we confirmed their expression during the larval stage and compared their quantitative expression in larvae from susceptible and a field-derived Cry1Ca resistant strain of S. litura. Among reduced transcript levels detected for most tested contigs in the Cry1Ca-resistant S. litura larvae, the most dramatic reduction (up to 99%) was detected for alkaline phosphatase contigs. This study significantly expands S. litura transcriptomic resources and provides preliminary identification of putative receptor genes with altered expression in S. litura resistant to Cry1Ca toxin.
Collapse
Affiliation(s)
- Liang Gong
- Key Laboratory of Plant Resource Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, Guangdong Province, China; Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China
| | - Huidong Wang
- Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China
| | - Jiangwei Qi
- Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China
| | - Lanzhi Han
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Meiying Hu
- Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China.
| | - Juan Luis Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, USA.
| |
Collapse
|