The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform

Jorg Bohlmann - One of the best experts on this subject based on the ideXlab platform.

  • Behavioral and Reproductive Response of White Pine Weevil (Pissodes strobi) to Resistant and Susceptible Sitka Spruce (Picea sitchensis).
    Insects, 2010
    Co-Authors: Jeanne A. Robert, Jorg Bohlmann
    Abstract:

    White pine weevil (Pissodes strobi, Peck.) is a native forest insect pest in the Pacific Northwest of North America that attacks species of Spruce (Picea spp.) and pine (Pinus spp.). Young Sitka Spruce [Picea sitchensis (Bong.) Carr.] trees are particularly susceptible to weevil attack. Pockets of naturally occurring Sitka Spruce resistance have been identified in high weevil hazard areas in coastal British Columbia. In this study, we characterize behavioral, physiological and reproductive responses of weevils to an extremely resistant Sitka Spruce genotype (H898) in comparison to a highly susceptible genotype (Q903). The experiments relied on a large number of three-year-old clonally propagated trees and were therefore restricted to two contrasting Sitka Spruce genotypes. When exposed to resistant trees, both male and female weevils were deterred during host selection and mating, females showed delayed or reduced ovary development, and successful reproduction of weevils was prevented on resistant trees.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: S. Ashley Byun Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

Aine L. Plant - One of the best experts on this subject based on the ideXlab platform.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: S. Ashley Byun Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

William L Hunter - One of the best experts on this subject based on the ideXlab platform.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: S. Ashley Byun Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

Shawn X. Wang - One of the best experts on this subject based on the ideXlab platform.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: S. Ashley Byun Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

Diane M Martin - One of the best experts on this subject based on the ideXlab platform.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • insect attack and wounding induce traumatic resin duct development and gene expression of pinene synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: Ashley Byun S Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.

  • Insect Attack and Wounding Induce Traumatic Resin Duct Development and Gene Expression of (—)-Pinene Synthase in Sitka Spruce
    Plant Physiology, 2003
    Co-Authors: S. Ashley Byun Mckay, William L Hunter, Shawn X. Wang, Diane M Martin, Jorg Bohlmann, Kimberley-ann Godard, Aine L. Plant
    Abstract:

    Conifers possess inducible terpenoid defense systems. These systems are associated with the formation of traumatic resin ducts (TRD) and are underpinned by enhanced gene expression and activity of terpene synthases (TPS), enzymes responsible for oleoresin formation. We first determined that Sitka Spruce (Picea sitchensis [Bong.] Carriere) had the capacity for TRD formation by mechanically wounding representative trees. We then proceeded to investigate whether the white pine weevil (Pissodes strobi Peck.), a stem-boring insect, can influence the expression of genes encoding monoterpene synthases (mono-tps) in Sitka Spruce. We went on to compare this response with the effects of a simulated insect attack by drill wounding. A significant increase in mono-tps transcript level was observed in the leaders of lateral branches of weevil-attacked and mechanically wounded trees. In this study, weevils induced a more rapid enhancement of mono-tps gene expression. A full-length Sitka Spruce mono-tps cDNA (PsTPS2) was isolated, expressed in Escherichia coli, and functionally identified as (—)-pinene synthase. The recombinant (—)-pinene synthase catalyzes the formation of (—)-α-pinene and (—)-β-pinene, both of which are known constituents of stem oleoresin in Sitka Spruce and increase in abundance after weevil attack. These data suggest that increased (—)-pinene synthase gene expression is an important element of the direct defense system deployed in Sitka Spruce after insect attack.