The Experts below are selected from a list of 621 Experts worldwide ranked by ideXlab platform
Yufa Peng - One of the best experts on this subject based on the ideXlab platform.
-
Chilo suppressalis and Sesamia inferens display different susceptibility responses to Cry1A insecticidal proteins
Pest Management Science, 2014Co-Authors: Cao Han, Lanzhi Han, Maolin Hou, Yufa PengAbstract:BACKGROUND Chilo suppressalis and Sesamia inferens are important lepidopteran rice pests that occur concurrently in rice-growing areas of China. The development of transgenic rice expressing Cry1A insecticidal proteins has provided a useful strategy for controlling these pests. RESULTS This study evaluated the baseline susceptibilities of C. suppressalis and S. inferens to Cry1A, as well as their responses to selection with Cry1A. Wide geographic variation in susceptibility was observed across all field populations. Within a given population, the LC50 of both Cry1Ab and Cry1Ac against S. inferens was drastically higher than that of C. suppressalis. Large LC50 differences (74.6-fold) were detected between the two species for Cry1Ab in the Poyang population, while small differences (3.6-fold) were detected for Cry1Ac in the Changsha population. The Cry1Ac LC50 of C. suppressalis and S. inferens increased 8.4- and 4.4-fold after 21 and eight selection generations respectively. Additionally, the estimated realised heritabilities (h2) of Cry1Ac tolerance were 0.11 in C. suppressalis and 0.292 in S. inferens. CONCLUSIONS S. inferens exhibited a significantly lower susceptibility and more rapidly evolved resistance to Cry1A compared with C. suppressalis. Therefore, S. inferens is more likely to evolve increased resistance, which threatens the sustainability of rice expressing Cry1A protein. © 2014 Society of Chemical Industry
-
binding site concentration explains the differential susceptibility of chilo suppressalis and Sesamia inferens to cry1a producing rice
Applied and Environmental Microbiology, 2014Co-Authors: Fajun Chen, Juan Luis Juratfuentes, Yufa PengAbstract:ABSTRACT Chilo suppressalis and Sesamia inferens are two important lepidopteran rice pests that occur concurrently during outbreaks in paddy fields in the main rice-growing areas of China. Previous and current field tests demonstrate that the transgenic rice line Huahui 1 (HH1) producing a Cry1Ab-Cry1Ac hybrid toxin from the bacterium Bacillus thuringiensis reduces egg and larval densities of C. suppressalis but not of S. inferens. This differential susceptibility to HH1 rice correlates with the reduced susceptibility to Cry1Ab and Cry1Ac toxins in S. inferens larvae compared to C. suppressalis larvae. The goal of this study was to identify the mechanism responsible for this differential susceptibility. In saturation binding assays, both Cry1Ab and Cry1Ac toxins bound with high affinity and in a saturable manner to midgut brush border membrane vesicles (BBMV) from C. suppressalis and S. inferens larvae. While binding affinities were similar, a dramatically lower concentration of Cry1A toxin binding sites was detected for S. inferens BBMV than for C. suppressalis BBMV. In contrast, no significant differences between species were detected for Cry1Ca toxin binding to BBMV. Ligand blotting detected BBMV proteins binding Cry1Ac or Cry1Ca toxins, some of them unique to C. suppressalis or S. inferens. These data support that reduced Cry1A binding site concentration is associated with a lower susceptibility to Cry1A toxins and HH1 rice in S. inferens larvae than in C. suppressalis larvae. Moreover, our data support Cry1Ca as a candidate for pyramiding efforts with Cry1A-producing rice to extend the activity range and durability of this technology against rice stem borers.
-
Evaluating the non-rice host plant species of Sesamia inferens (Lepidoptera: Noctuidae) as natural refuges: resistance management of Bt rice.
Environmental Entomology, 2011Co-Authors: Zhuorong Liu, Yulin Gao, Ju Luo, Fengxiang Lai, Yufa PengAbstract:ABSTRACT Although rice (Oryza sativa L.) lines that express Bacillus thuringiensis (Bt) toxins have shown great potential for managing the major Lepidoptera pests of rice in southern China, including Sesamia inferens, their long-term use is dependent on managing resistance development to Bt toxins in pest populations. The maintenance of “natural” refuges, non-Bt expressing plants that are hosts for a target pest, has been proposed as a means to minimize the evolution of resistance to Bt toxins in transgenic plants. In the current study, field surveys and greenhouse experiments were conducted to identify host plants of S. inferens that could serve as “natural” refuges in rice growing areas of southern China. A field survey showed that 34 plant species in four families can be alternative host plants of S. inferens. Based on injury level under field conditions, rice (Oryza sativa L.); water oat (Zizania latifolia Griseb.); corn (Zea mays L.); tidalmarsh flatsedge (Cyperus serotinus Rottb.); and narrowleaved ...
-
Lethal and Sub-Lethal Effects of Transgenic Rice Containing cry1Ac and CpTI Genes on the Pink Stem Borer, Sesamia inferens（Walker）
Agricultural Sciences in China, 2011Co-Authors: Lanzhi Han, Yufa Peng, Maolin Hou, Feng WangAbstract:Abstract Lethal and sub-lethal effects of transgenic rice containing cry1Ac and CpTI genes on the pink stem borer, Sesamia inferens, were studied to collect information for ecological risk assessment on insect-resistance of transgenic rice. In vitro insect-feeding bioassays were conducted to evaluate the lethal and sub-lethal effects of transgenic rice lines (II YouKF6 and KF6) containing cry1Ac+CpTI genes on S. inferens at four different growth stages, viz., seedling, tillering and elongation, booting, and milk and maturing. Transgenic rice at seedling stage showed significantly high lethal effect on S. inferens with the shortest lethal duration for 50 and 100% individuals and the highest corrected mortalities after feeding on transgenic lines at this stage for 3 and 6 d. Followed by tillering and elongation stage, 50 and 100% S. inferens were dead after feeding on transgenic lines at this stage for 4 and 10 d, respectively. Moreover, corrected mortalities for 6 d feeding on transgenic lines at this stage were significantly higher than that at booting, and milk and maturing stages. Lethal effect of KF6 on S. inferens decreased significantly at booting stage. Lethal duration for 50% S. inferens significantly extended and its corrected mortalities for 6 d feeding also declined remarkably. However, lethal effect of II YouKF6 on S. inferens did not decrease significantly at this stage. Transgenic rice at booting, and milk and maturing stages did not show significant lethal effect to S. inferens and it showed the longest lethal duration for 50% individuals and the lowest corrected mortalities for 3 and 6 d feeding. A few larvae of S. inferens could survive, pupate and emerge on these two transgenic lines at booting, and milk and maturing stages. Sub-lethal effect of two transgenic lines on S. inferens also differed significantly between different developmental stages. Continuously feeding on transgenic rice lines at seedling, and tillering and elongation stages delayed the development of larvae and pupae and decreased pupation rate, but no effect was observed on eclosion rate. Larval development was significantly inhibited after feeding on transgenic rice at booting stage, but no obvious effect was observed in pupal stage, pupation and eclosion rate. There were no significant differences for larval and pupal development, pupation, and eclosion rates between feeding on transgenic and control rice lines at milk and maturing stage. Larval and pupal weights significantly declined, but no influence was observed on fecundity when S. inferens infested on transgenic rice at any stage. These showed that there were significant differences in lethal and sub-lethal effects of transgenic rice on S. inferens among developmental stages, and the effects gradually decreased with the increase of growth stages of rice plant.
-
screen of bacillus thuringiensis toxins for transgenic rice to control Sesamia inferens and chilo suppressalis
Journal of Invertebrate Pathology, 2010Co-Authors: Yang Hu, Yufa Peng, Brenda Oppert, Qiang Fu, Jie Zhang, Zhitao ZhangAbstract:Abstract Transgenic rice to control stem borer damage is under development in China. To assess the potential of Bacillus thuringiensis (Bt) transgenes in stem borer control, the toxicity of five Bt protoxins (Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1Ca) against two rice stem borers, Sesamia inferens (pink stem borer) and Chilo suppressalis (striped stem borer), was evaluated in the laboratory by feeding neonate larvae on artificial diets containing Bt protoxins. The results indicated that Cry1Ca exhibited the highest level of toxicity to both stem borers, with an LC 50 of 0.24 and 0.30 μg/g for C. suppressalis and S. inferens , respectively. However, S. inferens was 4-fold lower in susceptibility to Cry1Aa, and 6- and 47-fold less susceptible to Cry1Ab and Cry1Ba, respectively, compared to C. suppressalis . To evaluate interactions among Bt protoxins in stem borer larvae, toxicity assays were performed with mixtures of Cry1Aa/Cry1Ab, Cry1Aa/Cry1Ca, Cry1Ac/Cry1Ca, Cry1Ac/Cry1Ba, Cry1Ab/Cry1Ac, Cry1Ab/Cry1Ba, and Cry1Ab/Cry1Ca at 1:1 (w/w) ratios. All protoxin mixtures demonstrated significant synergistic toxicity activity against C. suppressalis , with values of 1.6- to 11-fold higher toxicity than the theoretical additive effect. Surprisingly, all but one of the Bt protoxin mixtures were antagonistic in toxicity to S. inferens . In mortality-time response experiments, S. inferens demonstrated increased tolerance to Cry1Ab and Cry1Ac compared to C. suppressalis when treated with low or high protoxin concentrations. The data indicate the utility of Cry1Ca protoxin and a Cry1Ac/Cry1Ca mixture to control both stem borer populations.
Xiao-tian Tang - One of the best experts on this subject based on the ideXlab platform.
-
No evidence for an effect of Wolbachia on mtDNA variation and evolution in natural populations of Sesamia inferens (Lepidoptera: Noctuidae)
Journal of Integrative Agriculture, 2019Co-Authors: Xiao-tian TangAbstract:Abstract Wolbachia are widespread maternally-inherited endosymbiotic bacteria that infect numerous arthropods. This study represents a thorough survey of the Wolbachia infection patterns in the pink stem borer, Sesamia inferens (Walker), an important rice pest in China, based on nucleotide comparisons for the surface protein (wsp) and cell division protein (ftsZ) genes. The effects of Wolbachia on mtDNA variation and evolution of S. inferens were also investigated. Although we identified six genetically diverse strains, we found infections to be infrequent, with only 7.8% of hosts infected, and identified geographical differences in infection rates between southern and northern populations. Nucleotide indexes (haplotype diversity (Hd), nucleotide diversity (Π) and number of variable sites (S) of mtDNA in infected populations were not significantly lower or higher than that in the uninfected populations. Furthermore, there was no association between Wolbachia infection status and phylogeny of mtDNA haplotypes. Analysis of molecular variance (AMOVA) showed that significant differentiation mainly existed within groups rather than among the groups. Additionally, using Tajima's D and Fu's F values, the mtDNA genes did not deviate significantly from neutral evolution. Taken together these results indicate that currently there were no effects of Wolbachia infection on host mtDNA variation and evolution in S. inferens.
-
RESEARCH ARTICLE Exploring Valid Reference Genes for Quantitative Real-Time PCR Analysis in Sesamia inferens (Lepidoptera: Noctuidae)
2016Co-Authors: Meng Sun, Xiao-tian TangAbstract:The pink stem borer, Sesamia inferens, which is endemic in China and other parts of Asia, is a major pest of rice and causes significant yield loss in this host plant. Very few studies have addressed gene expression in S. inferens. Quantitative real-time PCR (qRT-PCR) is currently the most accurate and sensitive method for gene expression analysis. In qRT-PCR, data are normalized using reference genes, which help control for internal differences and reduce error between samples. In this study, seven candidate reference genes, 18S ribosomal RNA (18S rRNA), elongation factor 1 (EF1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein S13 (RPS13), ribosomal protein S20 (RPS20), tubulin (TUB), and β-actin (ACTB) were evaluated for their suitability in normalizing gene expression under different experimental conditions. The results indicated that three genes (RPS13, RPS20, and EF1) were optimal for normalizing gene expression in different insect tissues (head, epidermis, fat body, foregut, midgut, hindgut, Malpighian tubules, haemocytes, and salivary glands). 18S rRNA, EF1, andGAPDH were best for normalizing expression with respect to developmental stages and sex (egg masses; first, second, third, fourth, fifth, and sixth instar larvae; male and female pupae; and one-day-old male and female adults). 18S rRNA, RPS20, and TUB were optimal for fifth instars exposed to different temperatures (−8, −6, −4, −2, 0, and 27°C). To validate this recommendation, the expression profile of a target gene heat shock protein 83 gene (hsp83) was investigated, and results showed the selection was necessary and effective. In conclusion, this study describes reference gene sets that can be used to accurately measure gene expression in S. inferens
-
exploring valid reference genes for quantitative real time pcr analysis in Sesamia inferens lepidoptera noctuidae
PLOS ONE, 2015Co-Authors: Meng Sun, Xiao-tian TangAbstract:The pink stem borer, Sesamia inferens, which is endemic in China and other parts of Asia, is a major pest of rice and causes significant yield loss in this host plant. Very few studies have addressed gene expression in S. inferens. Quantitative real-time PCR (qRT-PCR) is currently the most accurate and sensitive method for gene expression analysis. In qRT-PCR, data are normalized using reference genes, which help control for internal differences and reduce error between samples. In this study, seven candidate reference genes, 18S ribosomal RNA (18S rRNA), elongation factor 1 (EF1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein S13 (RPS13), ribosomal protein S20 (RPS20), tubulin (TUB), and β-actin (ACTB) were evaluated for their suitability in normalizing gene expression under different experimental conditions. The results indicated that three genes (RPS13, RPS20, and EF1) were optimal for normalizing gene expression in different insect tissues (head, epidermis, fat body, foregut, midgut, hindgut, Malpighian tubules, haemocytes, and salivary glands). 18S rRNA, EF1, and GAPDH were best for normalizing expression with respect to developmental stages and sex (egg masses; first, second, third, fourth, fifth, and sixth instar larvae; male and female pupae; and one-day-old male and female adults). 18S rRNA, RPS20, and TUB were optimal for fifth instars exposed to different temperatures (−8, −6, −4, −2, 0, and 27°C). To validate this recommendation, the expression profile of a target gene heat shock protein 83 gene (hsp83) was investigated, and results showed the selection was necessary and effective. In conclusion, this study describes reference gene sets that can be used to accurately measure gene expression in S. inferens.
-
Expression patterns of five heat shock proteins in Sesamia inferens (Lepidoptera: Noctuidae) during heat stress
Journal of Asia-Pacific Entomology, 2015Co-Authors: Xiao-tian Tang, Meng SunAbstract:Abstract Heat shock proteins (HSPs) play important roles in the adaptation of organisms to environmental changes. In this study, we explore the role of HSPs during heat stress in Sesamia inferens (Walker) (Lepidoptera: Noctuidae), an important pest of rice. In order to understand the mechanistic basis of ecological adaptability and stress tolerance, we analyzed the expression profiles of genes encoding five S. inferens heat shock proteins (Sihsps) across temperature gradients by real-time quantitative PCR. Our results indicated that genes encoding ribosomal protein S13 (RPS13) and β-actin (ACTB) were the most stable reference genes under high temperature stress. The mRNA levels of Sihsp19.6, Sihsp20.6 and Sihsp83 were significantly up-regulated by heat stress; however, the expression of Sihsp21.4 and Sihsc70 did not vary significantly. The massive increase in the expression of Sihsp19.6 and Sihsp20.6 by thermal stress suggests a critical role in preventing cellular damage to S. inferens. Moreover, the threshold temperatures (39 °C for Sihsp19.6, Sihsp20.6 and Sihsp83) may partly explain the more southern distribution of S. inferens. Our results also support the contention that the absence of introns may favor the expression of stress-responsive genes (e.g. Sihsp19.6, Sihsp20.6 and Sihsp83 in the present study).
-
Characterization and Expression of Genes Encoding Three Small Heat Shock Proteins in Sesamia inferens (Lepidoptera: Noctuidae)
International Journal of Molecular Sciences, 2014Co-Authors: Meng Sun, Xiao-tian TangAbstract:The pink stem borer, Sesamia inferens (Walker), is a major pest of rice and is endemic in China and other parts of Asia. Small heat shock proteins (sHSPs) encompass a diverse, widespread class of stress proteins that have not been characterized in S. inferens. In the present study, we isolated and characterized three S. inferens genes that encode members of the α-crystallin/sHSP family, namely, Sihsp21.4, Sihsp20.6, and Sihsp19.6. The three cDNAs encoded proteins of 187, 183 and 174 amino acids with calculated molecular weights of 21.4, 20.6 and 19.6 kDa, respectively. The deduced amino acid sequences of the three genes showed strong similarity to sHSPs identified in other lepidopteran insects. Sihsp21.4 contained an intron, but Sihsp20.6 and Sihsp19.6 lacked introns. Real-time quantitative PCR analyses revealed that Sihsp21.4 was most strongly expressed in S. inferens heads; Whereas expression of Sihsp20.6 and Sihsp19.6 was highest in eggs. The three S. inferens sHSP genes were up-regulated during low temperature stress. In summary, our results show that S. inferens sHSP genes have distinct regulatory roles in the physiology of S. inferens.
Guo Wen - One of the best experts on this subject based on the ideXlab platform.
-
Food consumption,growth and survival of Sesamia inferens larvae on cry1Ab/cry1Ac-transformed gene Bt rice
Chinese Bulletin of Entomology, 2013Co-Authors: Guo WenAbstract:The food consumption,growth and survival of Sesamia inferens( Walker) larvae on cry1Ab / cry1Ac- transformed rice were measured by in vitro bioassay. The results show that both the cumulative and relative food consumption rates of 3rd and 5th instar larvae feeding on Bt rice were significantly reduced compared to those of larvae fed on the control variety. The net growth of both 3rd and 5th instar larvae fed on Bt rice was negative. The corrected mortality of 3rd instar larvae mostly reached 100%,and that of 5th instar larvae 85%,with increased time after feeding on Bt rice.
-
food consumption growth and survival of Sesamia inferens larvae on cry1ab cry1ac transformed gene bt rice
Chinese Bulletin of Entomology, 2013Co-Authors: Guo WenAbstract:The food consumption,growth and survival of Sesamia inferens( Walker) larvae on cry1Ab / cry1Ac- transformed rice were measured by in vitro bioassay. The results show that both the cumulative and relative food consumption rates of 3rd and 5th instar larvae feeding on Bt rice were significantly reduced compared to those of larvae fed on the control variety. The net growth of both 3rd and 5th instar larvae fed on Bt rice was negative. The corrected mortality of 3rd instar larvae mostly reached 100%,and that of 5th instar larvae 85%,with increased time after feeding on Bt rice.
-
Effects of transgenic cry1Ab/cry1Ac rice on the activities of three protective enzymes in larvae of Sesamia inferens (Lepidoptera:Noctuidae)
2012Co-Authors: Guo WenAbstract:To clarify the physiological and biochemical mechanism of the effect of transgenic cry1Ab/cry1Ac rice on larvae of Sesamia inferens (Walker) ,the effects of feeding transgenic Bt rice on the activities of three protective enzymes (SOD,CAT and POD) in S. inferens larvae were studied by assaying enzyme activities in the 3rd and 5th instar larvae which were fed with stems of transgenic and non-transgenic rice (control) for different time. The results showed that SOD activity in the 3rd instar larvae fed with Bt rice for 24 h was significantly higher than that of the control (increased by 43. 44%) , but declined to the minimum at 48 h after feeding. The POD activity in the 3rd larvae fed with Bt rice reached the maximum at 24 h after feeding,and significantly higher than that of the control (increased by 29. 22%) ,but declined to the minimum at 48 h after feeding which was significantly lower than that of the control. The CAT activity in the 3rd larvae fed with Bt rice for 4 h increased by 30. 33% ,and decreased by 27. 01% at 48 h after feeding compared with that of the control. The SOD activity in the 5th instar larvae was significantly higher than that of the control after the larvae was fed on transgenic rice for 4 h,but declined to the minimum at 36 h after feeding (decreased by 31. 62% compared with that of the control) . The POD activity reached the maximum and increased by 73. 20% compared with that of the control after the larvae was fed on Bt rice for 8 h,but declined to the minimum at 36 h after feeding. The CAT activity reached the maximum and increased by 75. 73% after the larvae was fed with transgenic rice for 4 h and decreased by 7. 55% at 48 h after feeding compared with that of the control. The resistance level of the 3rd instar larvae was lower than the 5th instar larvae when treated by transgenic Bt rice for the reason that the 3rd instar larvae had lower defense capability. The results suggest that in the initial stage of feeding,the enzyme activity in larvae increases in order to protect larvae from being damaged by Bt toxalbumin. The enzyme activities in larvae rapidly descend and the metabolism of larvae is disturbed due to feeding transgenic rice with extension of feeding time,causing the poisoning symptoms and even death of larvae.
-
effects of transgenic cry1ab cry1ac rice on the activities of three protective enzymes in larvae of Sesamia inferens lepidoptera noctuidae
Acta Entomologica Sinica, 2012Co-Authors: Guo WenAbstract:To clarify the physiological and biochemical mechanism of the effect of transgenic cry1Ab/cry1Ac rice on larvae of Sesamia inferens (Walker) ,the effects of feeding transgenic Bt rice on the activities of three protective enzymes (SOD,CAT and POD) in S. inferens larvae were studied by assaying enzyme activities in the 3rd and 5th instar larvae which were fed with stems of transgenic and non-transgenic rice (control) for different time. The results showed that SOD activity in the 3rd instar larvae fed with Bt rice for 24 h was significantly higher than that of the control (increased by 43. 44%) , but declined to the minimum at 48 h after feeding. The POD activity in the 3rd larvae fed with Bt rice reached the maximum at 24 h after feeding,and significantly higher than that of the control (increased by 29. 22%) ,but declined to the minimum at 48 h after feeding which was significantly lower than that of the control. The CAT activity in the 3rd larvae fed with Bt rice for 4 h increased by 30. 33% ,and decreased by 27. 01% at 48 h after feeding compared with that of the control. The SOD activity in the 5th instar larvae was significantly higher than that of the control after the larvae was fed on transgenic rice for 4 h,but declined to the minimum at 36 h after feeding (decreased by 31. 62% compared with that of the control) . The POD activity reached the maximum and increased by 73. 20% compared with that of the control after the larvae was fed on Bt rice for 8 h,but declined to the minimum at 36 h after feeding. The CAT activity reached the maximum and increased by 75. 73% after the larvae was fed with transgenic rice for 4 h and decreased by 7. 55% at 48 h after feeding compared with that of the control. The resistance level of the 3rd instar larvae was lower than the 5th instar larvae when treated by transgenic Bt rice for the reason that the 3rd instar larvae had lower defense capability. The results suggest that in the initial stage of feeding,the enzyme activity in larvae increases in order to protect larvae from being damaged by Bt toxalbumin. The enzyme activities in larvae rapidly descend and the metabolism of larvae is disturbed due to feeding transgenic rice with extension of feeding time,causing the poisoning symptoms and even death of larvae.
Meng Sun - One of the best experts on this subject based on the ideXlab platform.
-
RESEARCH ARTICLE Exploring Valid Reference Genes for Quantitative Real-Time PCR Analysis in Sesamia inferens (Lepidoptera: Noctuidae)
2016Co-Authors: Meng Sun, Xiao-tian TangAbstract:The pink stem borer, Sesamia inferens, which is endemic in China and other parts of Asia, is a major pest of rice and causes significant yield loss in this host plant. Very few studies have addressed gene expression in S. inferens. Quantitative real-time PCR (qRT-PCR) is currently the most accurate and sensitive method for gene expression analysis. In qRT-PCR, data are normalized using reference genes, which help control for internal differences and reduce error between samples. In this study, seven candidate reference genes, 18S ribosomal RNA (18S rRNA), elongation factor 1 (EF1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein S13 (RPS13), ribosomal protein S20 (RPS20), tubulin (TUB), and β-actin (ACTB) were evaluated for their suitability in normalizing gene expression under different experimental conditions. The results indicated that three genes (RPS13, RPS20, and EF1) were optimal for normalizing gene expression in different insect tissues (head, epidermis, fat body, foregut, midgut, hindgut, Malpighian tubules, haemocytes, and salivary glands). 18S rRNA, EF1, andGAPDH were best for normalizing expression with respect to developmental stages and sex (egg masses; first, second, third, fourth, fifth, and sixth instar larvae; male and female pupae; and one-day-old male and female adults). 18S rRNA, RPS20, and TUB were optimal for fifth instars exposed to different temperatures (−8, −6, −4, −2, 0, and 27°C). To validate this recommendation, the expression profile of a target gene heat shock protein 83 gene (hsp83) was investigated, and results showed the selection was necessary and effective. In conclusion, this study describes reference gene sets that can be used to accurately measure gene expression in S. inferens
-
exploring valid reference genes for quantitative real time pcr analysis in Sesamia inferens lepidoptera noctuidae
PLOS ONE, 2015Co-Authors: Meng Sun, Xiao-tian TangAbstract:The pink stem borer, Sesamia inferens, which is endemic in China and other parts of Asia, is a major pest of rice and causes significant yield loss in this host plant. Very few studies have addressed gene expression in S. inferens. Quantitative real-time PCR (qRT-PCR) is currently the most accurate and sensitive method for gene expression analysis. In qRT-PCR, data are normalized using reference genes, which help control for internal differences and reduce error between samples. In this study, seven candidate reference genes, 18S ribosomal RNA (18S rRNA), elongation factor 1 (EF1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal protein S13 (RPS13), ribosomal protein S20 (RPS20), tubulin (TUB), and β-actin (ACTB) were evaluated for their suitability in normalizing gene expression under different experimental conditions. The results indicated that three genes (RPS13, RPS20, and EF1) were optimal for normalizing gene expression in different insect tissues (head, epidermis, fat body, foregut, midgut, hindgut, Malpighian tubules, haemocytes, and salivary glands). 18S rRNA, EF1, and GAPDH were best for normalizing expression with respect to developmental stages and sex (egg masses; first, second, third, fourth, fifth, and sixth instar larvae; male and female pupae; and one-day-old male and female adults). 18S rRNA, RPS20, and TUB were optimal for fifth instars exposed to different temperatures (−8, −6, −4, −2, 0, and 27°C). To validate this recommendation, the expression profile of a target gene heat shock protein 83 gene (hsp83) was investigated, and results showed the selection was necessary and effective. In conclusion, this study describes reference gene sets that can be used to accurately measure gene expression in S. inferens.
-
Expression patterns of five heat shock proteins in Sesamia inferens (Lepidoptera: Noctuidae) during heat stress
Journal of Asia-Pacific Entomology, 2015Co-Authors: Xiao-tian Tang, Meng SunAbstract:Abstract Heat shock proteins (HSPs) play important roles in the adaptation of organisms to environmental changes. In this study, we explore the role of HSPs during heat stress in Sesamia inferens (Walker) (Lepidoptera: Noctuidae), an important pest of rice. In order to understand the mechanistic basis of ecological adaptability and stress tolerance, we analyzed the expression profiles of genes encoding five S. inferens heat shock proteins (Sihsps) across temperature gradients by real-time quantitative PCR. Our results indicated that genes encoding ribosomal protein S13 (RPS13) and β-actin (ACTB) were the most stable reference genes under high temperature stress. The mRNA levels of Sihsp19.6, Sihsp20.6 and Sihsp83 were significantly up-regulated by heat stress; however, the expression of Sihsp21.4 and Sihsc70 did not vary significantly. The massive increase in the expression of Sihsp19.6 and Sihsp20.6 by thermal stress suggests a critical role in preventing cellular damage to S. inferens. Moreover, the threshold temperatures (39 °C for Sihsp19.6, Sihsp20.6 and Sihsp83) may partly explain the more southern distribution of S. inferens. Our results also support the contention that the absence of introns may favor the expression of stress-responsive genes (e.g. Sihsp19.6, Sihsp20.6 and Sihsp83 in the present study).
-
Characterization and Expression of Genes Encoding Three Small Heat Shock Proteins in Sesamia inferens (Lepidoptera: Noctuidae)
International Journal of Molecular Sciences, 2014Co-Authors: Meng Sun, Xiao-tian TangAbstract:The pink stem borer, Sesamia inferens (Walker), is a major pest of rice and is endemic in China and other parts of Asia. Small heat shock proteins (sHSPs) encompass a diverse, widespread class of stress proteins that have not been characterized in S. inferens. In the present study, we isolated and characterized three S. inferens genes that encode members of the α-crystallin/sHSP family, namely, Sihsp21.4, Sihsp20.6, and Sihsp19.6. The three cDNAs encoded proteins of 187, 183 and 174 amino acids with calculated molecular weights of 21.4, 20.6 and 19.6 kDa, respectively. The deduced amino acid sequences of the three genes showed strong similarity to sHSPs identified in other lepidopteran insects. Sihsp21.4 contained an intron, but Sihsp20.6 and Sihsp19.6 lacked introns. Real-time quantitative PCR analyses revealed that Sihsp21.4 was most strongly expressed in S. inferens heads; Whereas expression of Sihsp20.6 and Sihsp19.6 was highest in eggs. The three S. inferens sHSP genes were up-regulated during low temperature stress. In summary, our results show that S. inferens sHSP genes have distinct regulatory roles in the physiology of S. inferens.
-
First Microsatellites from Sesamia inferens (Lepidoptera: Noctuidae)
Annals of the Entomological Society of America, 2014Co-Authors: Xiao-tian Tang, Meng Sun, Fang-fang XieAbstract:ABSTRACT The pink stem borer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae), is an important pest of rice in China and other parts of Asia. The wide geographic distribution and broad host range of S. inferens is likely to result in high genetic variability within the species. To better understand the genetic structure and phylogeography of this pest, 30 polymorphic microsatellite loci were developed and characterized by fast isolation by amplified fragment length polymorphism of sequences containing repeats (FIASCO). Our results from two geographic locations (Yangzhou and Guiyang) showed that the polymorphic information content (PIC) ranged from 0.181 to 0.947, with an average of 0.633 (relatively high polymorphism). The number of alleles per locus ranged from 2 to 31, with expected heterozygosities from 0.196 to 0.962 and observed heterozygosities from 0.043 to 1.000. Fourteen loci showed no significant departure from Hardy—Weinberg equilibrium after sequential Bonferroni's correction at least in on...
Zhitao Zhang - One of the best experts on this subject based on the ideXlab platform.
-
screen of bacillus thuringiensis toxins for transgenic rice to control Sesamia inferens and chilo suppressalis
Journal of Invertebrate Pathology, 2010Co-Authors: Yang Hu, Yufa Peng, Brenda Oppert, Qiang Fu, Jie Zhang, Zhitao ZhangAbstract:Abstract Transgenic rice to control stem borer damage is under development in China. To assess the potential of Bacillus thuringiensis (Bt) transgenes in stem borer control, the toxicity of five Bt protoxins (Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1Ca) against two rice stem borers, Sesamia inferens (pink stem borer) and Chilo suppressalis (striped stem borer), was evaluated in the laboratory by feeding neonate larvae on artificial diets containing Bt protoxins. The results indicated that Cry1Ca exhibited the highest level of toxicity to both stem borers, with an LC 50 of 0.24 and 0.30 μg/g for C. suppressalis and S. inferens , respectively. However, S. inferens was 4-fold lower in susceptibility to Cry1Aa, and 6- and 47-fold less susceptible to Cry1Ab and Cry1Ba, respectively, compared to C. suppressalis . To evaluate interactions among Bt protoxins in stem borer larvae, toxicity assays were performed with mixtures of Cry1Aa/Cry1Ab, Cry1Aa/Cry1Ca, Cry1Ac/Cry1Ca, Cry1Ac/Cry1Ba, Cry1Ab/Cry1Ac, Cry1Ab/Cry1Ba, and Cry1Ab/Cry1Ca at 1:1 (w/w) ratios. All protoxin mixtures demonstrated significant synergistic toxicity activity against C. suppressalis , with values of 1.6- to 11-fold higher toxicity than the theoretical additive effect. Surprisingly, all but one of the Bt protoxin mixtures were antagonistic in toxicity to S. inferens . In mortality-time response experiments, S. inferens demonstrated increased tolerance to Cry1Ab and Cry1Ac compared to C. suppressalis when treated with low or high protoxin concentrations. The data indicate the utility of Cry1Ca protoxin and a Cry1Ac/Cry1Ca mixture to control both stem borer populations.