Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.

Herbicide efficacy is known to be influenced by temperature, however, underlying mechanism(s) are poorly understood. A marked alteration in mesotrione [a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor] efficacy on Palmer amaranth (Amaranthus palmeri S. Watson) was observed when grown under low...

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Main Authors: Amar S Godar, Vijaya K Varanasi, Sridevi Nakka, P V Vara Prasad, Curtis R Thompson, J Mithila
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0126731
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author Amar S Godar
Vijaya K Varanasi
Sridevi Nakka
P V Vara Prasad
Curtis R Thompson
J Mithila
author_facet Amar S Godar
Vijaya K Varanasi
Sridevi Nakka
P V Vara Prasad
Curtis R Thompson
J Mithila
author_sort Amar S Godar
collection DOAJ
description Herbicide efficacy is known to be influenced by temperature, however, underlying mechanism(s) are poorly understood. A marked alteration in mesotrione [a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor] efficacy on Palmer amaranth (Amaranthus palmeri S. Watson) was observed when grown under low- (LT, 25/15 °C, day/night temperatures) and high (HT, 40/30° C) temperature compared to optimum (OT, 32.5/22.5 °C) temperature. Based on plant height, injury, and mortality, Palmer amaranth was more sensitive to mesotrione at LT and less sensitive at HT compared to OT (ED50 for mortality; 18.5, 52.3, and 63.7 g ai ha-1, respectively). Similar responses were observed for leaf chlorophyll index and photochemical efficiency of PSII (Fv/Fm). Furthermore, mesotrione translocation and metabolism, and HPPD expression data strongly supported such variation. Relatively more mesotrione was translocated to meristematic regions at LT or OT than at HT. Based on T50 values (time required to metabolize 50% of the 14C mesotrione), plants at HT metabolized mesotrione faster than those at LT or OT (T50; 13, 21, and 16.5 h, respectively). The relative HPPD:CPS (carbamoyl phosphate synthetase) or HPPD:β-tubulin expression in mesotrione-treated plants increased over time in all temperature regimes; however, at 48 HAT, the HPPD:β-tubulin expression was exceedingly higher at HT compared to LT or OT (18.4-, 3.1-, and 3.5-fold relative to untreated plants, respectively). These findings together with an integrated understanding of other interacting key environmental factors will have important implications for a predictable approach for effective weed management.
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spelling doaj.art-aa10590bad71494db2289abbd3ee8aa02022-12-21T19:11:13ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01105e012673110.1371/journal.pone.0126731Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.Amar S GodarVijaya K VaranasiSridevi NakkaP V Vara PrasadCurtis R ThompsonJ MithilaHerbicide efficacy is known to be influenced by temperature, however, underlying mechanism(s) are poorly understood. A marked alteration in mesotrione [a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor] efficacy on Palmer amaranth (Amaranthus palmeri S. Watson) was observed when grown under low- (LT, 25/15 °C, day/night temperatures) and high (HT, 40/30° C) temperature compared to optimum (OT, 32.5/22.5 °C) temperature. Based on plant height, injury, and mortality, Palmer amaranth was more sensitive to mesotrione at LT and less sensitive at HT compared to OT (ED50 for mortality; 18.5, 52.3, and 63.7 g ai ha-1, respectively). Similar responses were observed for leaf chlorophyll index and photochemical efficiency of PSII (Fv/Fm). Furthermore, mesotrione translocation and metabolism, and HPPD expression data strongly supported such variation. Relatively more mesotrione was translocated to meristematic regions at LT or OT than at HT. Based on T50 values (time required to metabolize 50% of the 14C mesotrione), plants at HT metabolized mesotrione faster than those at LT or OT (T50; 13, 21, and 16.5 h, respectively). The relative HPPD:CPS (carbamoyl phosphate synthetase) or HPPD:β-tubulin expression in mesotrione-treated plants increased over time in all temperature regimes; however, at 48 HAT, the HPPD:β-tubulin expression was exceedingly higher at HT compared to LT or OT (18.4-, 3.1-, and 3.5-fold relative to untreated plants, respectively). These findings together with an integrated understanding of other interacting key environmental factors will have important implications for a predictable approach for effective weed management.https://doi.org/10.1371/journal.pone.0126731
spellingShingle Amar S Godar
Vijaya K Varanasi
Sridevi Nakka
P V Vara Prasad
Curtis R Thompson
J Mithila
Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.
PLoS ONE
title Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.
title_full Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.
title_fullStr Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.
title_full_unstemmed Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.
title_short Physiological and Molecular Mechanisms of Differential Sensitivity of Palmer Amaranth (Amaranthus palmeri) to Mesotrione at Varying Growth Temperatures.
title_sort physiological and molecular mechanisms of differential sensitivity of palmer amaranth amaranthus palmeri to mesotrione at varying growth temperatures
url https://doi.org/10.1371/journal.pone.0126731
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