The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

Johnathan A. Napier - One of the best experts on this subject based on the ideXlab platform.

  • Isolation and expression pattern of two putative acyl‐ACP desaturase cDNAs from Bassia scoparia
    Journal of experimental botany, 2004
    Co-Authors: Heather M. Whitney, Olga Sayanova, John A. Pickett, Johnathan A. Napier
    Abstract:

    The seed lipids of some higher plants contain unusual fatty acids with potentially valuable non-food uses. Seeds of Bassia scoparia contain one such monounsaturated fatty acid, 16:1D 5 . This fatty acid can be used for the production of an insect ovipo- sition pheromone, which is potentially valuable in the control of the mosquito Culex quinquefasciatus, a vector of West Nile virus. Previous work has established that a number of unusual monounsaturated fatty acids are produced by variant forms of the ubiquitous acyl-ACP desaturases. The isolation and initial characterization of two putative acyl-ACP desaturases from B. scoparia, one of which is seed-specific, suggests that such a variant enzyme occurs in this species.

  • isolation and expression pattern of two putative acyl acp desaturase cdnas from Bassia scoparia
    Journal of Experimental Botany, 2004
    Co-Authors: Heather M. Whitney, Olga Sayanova, John A. Pickett, Johnathan A. Napier
    Abstract:

    The seed lipids of some higher plants contain unusual fatty acids with potentially valuable non-food uses. Seeds of Bassia scoparia contain one such monounsaturated fatty acid, 16:1D 5 . This fatty acid can be used for the production of an insect ovipo- sition pheromone, which is potentially valuable in the control of the mosquito Culex quinquefasciatus, a vector of West Nile virus. Previous work has established that a number of unusual monounsaturated fatty acids are produced by variant forms of the ubiquitous acyl-ACP desaturases. The isolation and initial characterization of two putative acyl-ACP desaturases from B. scoparia, one of which is seed-specific, suggests that such a variant enzyme occurs in this species.

R. Douglas Sammons - One of the best experts on this subject based on the ideXlab platform.

  • Investigating the presence of compensatory evolution in dicamba resistant IAA16 mutated kochia (Bassia scoparia)€.
    Pest management science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance. This article is protected by copyright. All rights reserved.

  • A dicamba resistance-endowing IAA16 mutation leads to significant vegetative growth defects and impaired competitiveness in kochia (Bassia scoparia)†.
    Pest management science, 2020
    Co-Authors: Sherry Leclere, Phil Westra, Kang Liu, Marta Paciorek, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    BACKGROUND Precise quantification of the fitness cost of synthetic auxin resistance has been impeded by lack of knowledge about the genetic basis of resistance in weeds. Recent elucidation of a resistance-endowing IAA16 mutation (G73N) in the key weed species kochia (Bassia scoparia), allows detailed characterization of the contribution of resistance alleles to weed fitness, both in the presence and absence of herbicides. Different G73N genotypes from a segregating resistant parental line (9425) were characterized for cross-resistance to dicamba, 2,4-d and fluroxypyr, and changes on stem/leaf morphology and plant architecture. Plant competitiveness and dominance of the fitness effects was quantified through measuring biomass and seed production of three F2 lines in two runs of glasshouse replacement series studies. RESULTS G73N confers robust resistance to dicamba but only moderate to weak resistance to 2,4-D and fluroxypyr. G73N mutant plants displayed significant vegetative growth defects: (i) they were 30-50% shorter, with a more tumbling style plant architecture, and (ii) they had thicker and more ovate (versus lanceolate and linear) leaf blades with lower photosynthesis efficiency, and 40-60% smaller stems with less-developed vascular bundle systems. F2 mutant plants had impaired plant competitiveness, which can lead to 80-90% less biomass and seed production in the replacement series study. The pleiotropic effects of G73N were mostly semidominant (0.5) and fluctuated with the environments and traits measured. CONCLUSION G73N is associated with significant vegetative growth defects and reduced competitiveness in synthetic auxin-resistant kochia. Management practices should target resistant kochia's high vulnerability to competition in order to effectively contain the spread of resistance.

Marta Paciorek - One of the best experts on this subject based on the ideXlab platform.

  • investigating the presence of compensatory evolution in dicamba resistant iaa16 mutated kochia Bassia scoparia
    Pest Management Science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perezjones, Douglas R Sammons
    Abstract:

    BACKGROUND Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. RESULTS G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. CONCLUSION The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance.

  • Investigating the presence of compensatory evolution in dicamba resistant IAA16 mutated kochia (Bassia scoparia)€.
    Pest management science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance. This article is protected by copyright. All rights reserved.

  • A dicamba resistance-endowing IAA16 mutation leads to significant vegetative growth defects and impaired competitiveness in kochia (Bassia scoparia)†.
    Pest management science, 2020
    Co-Authors: Sherry Leclere, Phil Westra, Kang Liu, Marta Paciorek, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    BACKGROUND Precise quantification of the fitness cost of synthetic auxin resistance has been impeded by lack of knowledge about the genetic basis of resistance in weeds. Recent elucidation of a resistance-endowing IAA16 mutation (G73N) in the key weed species kochia (Bassia scoparia), allows detailed characterization of the contribution of resistance alleles to weed fitness, both in the presence and absence of herbicides. Different G73N genotypes from a segregating resistant parental line (9425) were characterized for cross-resistance to dicamba, 2,4-d and fluroxypyr, and changes on stem/leaf morphology and plant architecture. Plant competitiveness and dominance of the fitness effects was quantified through measuring biomass and seed production of three F2 lines in two runs of glasshouse replacement series studies. RESULTS G73N confers robust resistance to dicamba but only moderate to weak resistance to 2,4-D and fluroxypyr. G73N mutant plants displayed significant vegetative growth defects: (i) they were 30-50% shorter, with a more tumbling style plant architecture, and (ii) they had thicker and more ovate (versus lanceolate and linear) leaf blades with lower photosynthesis efficiency, and 40-60% smaller stems with less-developed vascular bundle systems. F2 mutant plants had impaired plant competitiveness, which can lead to 80-90% less biomass and seed production in the replacement series study. The pleiotropic effects of G73N were mostly semidominant (0.5) and fluctuated with the environments and traits measured. CONCLUSION G73N is associated with significant vegetative growth defects and reduced competitiveness in synthetic auxin-resistant kochia. Management practices should target resistant kochia's high vulnerability to competition in order to effectively contain the spread of resistance.

Sherry Leclere - One of the best experts on this subject based on the ideXlab platform.

  • investigating the presence of compensatory evolution in dicamba resistant iaa16 mutated kochia Bassia scoparia
    Pest Management Science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perezjones, Douglas R Sammons
    Abstract:

    BACKGROUND Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. RESULTS G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. CONCLUSION The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance.

  • Investigating the presence of compensatory evolution in dicamba resistant IAA16 mutated kochia (Bassia scoparia)€.
    Pest management science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance. This article is protected by copyright. All rights reserved.

  • A dicamba resistance-endowing IAA16 mutation leads to significant vegetative growth defects and impaired competitiveness in kochia (Bassia scoparia)†.
    Pest management science, 2020
    Co-Authors: Sherry Leclere, Phil Westra, Kang Liu, Marta Paciorek, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    BACKGROUND Precise quantification of the fitness cost of synthetic auxin resistance has been impeded by lack of knowledge about the genetic basis of resistance in weeds. Recent elucidation of a resistance-endowing IAA16 mutation (G73N) in the key weed species kochia (Bassia scoparia), allows detailed characterization of the contribution of resistance alleles to weed fitness, both in the presence and absence of herbicides. Different G73N genotypes from a segregating resistant parental line (9425) were characterized for cross-resistance to dicamba, 2,4-d and fluroxypyr, and changes on stem/leaf morphology and plant architecture. Plant competitiveness and dominance of the fitness effects was quantified through measuring biomass and seed production of three F2 lines in two runs of glasshouse replacement series studies. RESULTS G73N confers robust resistance to dicamba but only moderate to weak resistance to 2,4-D and fluroxypyr. G73N mutant plants displayed significant vegetative growth defects: (i) they were 30-50% shorter, with a more tumbling style plant architecture, and (ii) they had thicker and more ovate (versus lanceolate and linear) leaf blades with lower photosynthesis efficiency, and 40-60% smaller stems with less-developed vascular bundle systems. F2 mutant plants had impaired plant competitiveness, which can lead to 80-90% less biomass and seed production in the replacement series study. The pleiotropic effects of G73N were mostly semidominant (0.5) and fluctuated with the environments and traits measured. CONCLUSION G73N is associated with significant vegetative growth defects and reduced competitiveness in synthetic auxin-resistant kochia. Management practices should target resistant kochia's high vulnerability to competition in order to effectively contain the spread of resistance.

Phil Westra - One of the best experts on this subject based on the ideXlab platform.

  • Investigating the presence of compensatory evolution in dicamba resistant IAA16 mutated kochia (Bassia scoparia)€.
    Pest management science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance. This article is protected by copyright. All rights reserved.

  • investigating the presence of compensatory evolution in dicamba resistant iaa16 mutated kochia Bassia scoparia
    Pest Management Science, 2020
    Co-Authors: Marta Paciorek, Phil Westra, Sherry Leclere, Kang Liu, Alejandro Perezjones, Douglas R Sammons
    Abstract:

    BACKGROUND Lack of fitness cost have been reported for multiple herbicide resistance traits, but the underlying evolutionary mechanisms are not well understood. Compensatory evolution that ameliorates resistance costs, has been documented in bacteria and insects but rarely studied in weeds. Dicamba resistant IAA16 (G73N) mutated kochia was previously found to have high fecundity in the absence of competition, regardless of significant vegetative growth defects. To understand if costs of dicamba resistance can be compensated through traits promoting reproductive success in kochia, we thoroughly characterized the reproductive growth and development of different G73N kochia biotypes. Flowering phenology, seed production and reproductive allocation were quantified through greenhouse studies, floral (stigma-anthers distance) and seed morphology, as well as resulting mating and seed dispersal systems were studied through time-course microcopy images. RESULTS G73N covaried with multiple phenological, morphological and ecological traits that improve reproductive fitness: 1) 16-60% higher reproductive allocation; 2) longer reproduction phase through early flowering (2-7d); 3) smaller stigma-anthers separation (up to 60% reduction of herkogamy and dichogamy) that can potentially promote selfing and reproductive assurance; 4) "winged" seeds with 30-70% longer sepals that facilitate long-distance seed dispersal. CONCLUSION The current study demonstrates that costs of herbicide resistance can be ameliorated through coevolution of other fitness penalty alleviating traits. As illustrated in a hypothetical model, the evolution of herbicide resistance is an ongoing fitness maximization process, which posts challenges to contain the spread of resistance.

  • A dicamba resistance-endowing IAA16 mutation leads to significant vegetative growth defects and impaired competitiveness in kochia (Bassia scoparia)†.
    Pest management science, 2020
    Co-Authors: Sherry Leclere, Phil Westra, Kang Liu, Marta Paciorek, Alejandro Perez-jones, R. Douglas Sammons
    Abstract:

    BACKGROUND Precise quantification of the fitness cost of synthetic auxin resistance has been impeded by lack of knowledge about the genetic basis of resistance in weeds. Recent elucidation of a resistance-endowing IAA16 mutation (G73N) in the key weed species kochia (Bassia scoparia), allows detailed characterization of the contribution of resistance alleles to weed fitness, both in the presence and absence of herbicides. Different G73N genotypes from a segregating resistant parental line (9425) were characterized for cross-resistance to dicamba, 2,4-d and fluroxypyr, and changes on stem/leaf morphology and plant architecture. Plant competitiveness and dominance of the fitness effects was quantified through measuring biomass and seed production of three F2 lines in two runs of glasshouse replacement series studies. RESULTS G73N confers robust resistance to dicamba but only moderate to weak resistance to 2,4-D and fluroxypyr. G73N mutant plants displayed significant vegetative growth defects: (i) they were 30-50% shorter, with a more tumbling style plant architecture, and (ii) they had thicker and more ovate (versus lanceolate and linear) leaf blades with lower photosynthesis efficiency, and 40-60% smaller stems with less-developed vascular bundle systems. F2 mutant plants had impaired plant competitiveness, which can lead to 80-90% less biomass and seed production in the replacement series study. The pleiotropic effects of G73N were mostly semidominant (0.5) and fluctuated with the environments and traits measured. CONCLUSION G73N is associated with significant vegetative growth defects and reduced competitiveness in synthetic auxin-resistant kochia. Management practices should target resistant kochia's high vulnerability to competition in order to effectively contain the spread of resistance.

  • Herbicide options for glyphosate-resistant kochia (Bassia scoparia) management in the Great Plains
    Weed Technology, 2019
    Co-Authors: Gustavo M. Sbatella, Phillip W. Stahlman, Andrew R. Kniss, Albert T. Adjesiwor, Phil Westra, Michael Moechnig, Robert G. Wilson
    Abstract:

    Kochia is one of the most problematic weeds in the United States. Field studies were conducted in five states (Wyoming, Colorado, Kansas, Nebraska, and South Dakota) over 2 yr (2010 and 2011) to evaluate kochia control with selected herbicides registered in five common crop scenarios: winter wheat, fallow, corn, soybean, and sugar beet to provide insight for diversifying kochia management in crop rotations. Kochia control varied by experimental site such that more variation in kochia control and biomass production was explained by experimental site than herbicide choice within a crop. Kochia control with herbicides currently labeled for use in sugar beet averaged 32% across locations. Kochia control was greatest and most consistent from corn herbicide programs (99%), followed by soybean (96%) and fallow (97%) herbicide programs. Kochia control from wheat herbicide programs was 93%. With respect to the availability of effective herbicide options, glyphosate-resistant kochia control was easiest in corn, soybean, and fallow, followed by wheat; and difficult to manage with herbicides in sugar beet. Nomenclature: Glyphosate; kochia, Bassia scoparia (L.) A. J. Scott, KCHSC; corn, Zea mays L. ZEAMX; soybean, Glycine max (L.) Merr. GLXMA; sugar beet, Beta vulgaris L. BEAVX; wheat, Triticum aestivum L. TRZAX