The Experts below are selected from a list of 5511 Experts worldwide ranked by ideXlab platform

Joachim R. De Miranda - One of the best experts on this subject based on the ideXlab platform.

  • increased tolerance and resistance to virus infections a possible factor in the survival of varroa destructor resistant honey bees apis mellifera
    PLOS ONE, 2014
    Co-Authors: Barbara Locke, Eva Forsgren, Joachim R. De Miranda
    Abstract:

    The honey bee ectoparasitic Mite, Varroa destructor, has a world-wide distribution and inflicts more damage than all other known apicultural diseases. However, Varroa-induced colony mortality is more accurately a result of secondary virus infections vectored by the Mite. This means that honey bee resistance to Varroa may include resistance or tolerance to virus infections. The aim of this study was to see if this is the case for a unique population of Mite-resistant (MR) European honey bees on the island of Gotland, Sweden. This population has survived uncontrolled Mite Infestation for over a decade, developing specific Mite-related resistance traits to do so. Using RT-qPCR techniques, we monitored late season virus infections, Varroa Mite Infestation and honey bee colony population dynamics in the Gotland MR population and compared this to Mite-susceptible (MS) colonies in a close by apiary. From summer to autumn the deformed wing virus (DWV) titres increased similarly between the MR and MS populations, while the black queen cell virus (BQCV) and sacbrood virus (SBV) titres decreased substantially in the MR population compared to the MS population by several orders of magnitude. The MR colonies all survived the following winter with high Mite Infestation, high DWV infection, small colony size and low proportions of autumn brood, while the MS colonies all perished. Possible explanations for these changes in virus titres and their relevance to Varroa resistance and colony winter survival are discussed.

  • Acaricide Treatment Affects Viral Dynamics in Varroa destructor-Infested Honey Bee Colonies via both Host Physiology and Mite Control
    Applied and Environmental Microbiology, 2012
    Co-Authors: Barbara Locke, Ingemar Fries, Eva Forsgren, Joachim R. De Miranda
    Abstract:

    Honey bee ( Apis mellifera ) colonies are declining, and a number of stressors have been identified that affect, alone or in combination, the health of honey bees. The ectoparasitic Mite Varroa destructor , honey bee viruses that are often closely associated with the Mite, and pesticides used to control the Mite population form a complex system of stressors that may affect honey bee health in different ways. During an acaricide treatment using Apistan (plastic strips coated with tau-fluvalinate), we analyzed the infection dynamics of deformed wing virus (DWV), sacbrood virus (SBV), and black queen cell virus (BQCV) in adult bees, Mite-infested pupae, their associated Varroa Mites, and uninfested pupae, comparing these to similar samples from untreated control colonies. Titers of DWV increased initially with the onset of the acaricide application and then slightly decreased progressively coinciding with the removal of the Varroa Mite Infestation. This initial increase in DWV titers suggests a physiological effect of tau-fluvalinate on the host's susceptibility to viral infection. DWV titers in adult bees and uninfested pupae remained higher in treated colonies than in untreated colonies. The titers of SBV and BQCV did not show any direct relationship with Mite Infestation and showed a variety of possible effects of the acaricide treatment. The results indicate that other factors besides Varroa Mite Infestation may be important to the development and maintenance of damaging DWV titers in colonies. Possible biochemical explanations for the observed synergistic effects between tau-fluvalinate and virus infections are discussed.

Barbara Locke - One of the best experts on this subject based on the ideXlab platform.

  • increased tolerance and resistance to virus infections a possible factor in the survival of varroa destructor resistant honey bees apis mellifera
    PLOS ONE, 2014
    Co-Authors: Barbara Locke, Eva Forsgren, Joachim R. De Miranda
    Abstract:

    The honey bee ectoparasitic Mite, Varroa destructor, has a world-wide distribution and inflicts more damage than all other known apicultural diseases. However, Varroa-induced colony mortality is more accurately a result of secondary virus infections vectored by the Mite. This means that honey bee resistance to Varroa may include resistance or tolerance to virus infections. The aim of this study was to see if this is the case for a unique population of Mite-resistant (MR) European honey bees on the island of Gotland, Sweden. This population has survived uncontrolled Mite Infestation for over a decade, developing specific Mite-related resistance traits to do so. Using RT-qPCR techniques, we monitored late season virus infections, Varroa Mite Infestation and honey bee colony population dynamics in the Gotland MR population and compared this to Mite-susceptible (MS) colonies in a close by apiary. From summer to autumn the deformed wing virus (DWV) titres increased similarly between the MR and MS populations, while the black queen cell virus (BQCV) and sacbrood virus (SBV) titres decreased substantially in the MR population compared to the MS population by several orders of magnitude. The MR colonies all survived the following winter with high Mite Infestation, high DWV infection, small colony size and low proportions of autumn brood, while the MS colonies all perished. Possible explanations for these changes in virus titres and their relevance to Varroa resistance and colony winter survival are discussed.

  • Acaricide Treatment Affects Viral Dynamics in Varroa destructor-Infested Honey Bee Colonies via both Host Physiology and Mite Control
    Applied and Environmental Microbiology, 2012
    Co-Authors: Barbara Locke, Ingemar Fries, Eva Forsgren, Joachim R. De Miranda
    Abstract:

    Honey bee ( Apis mellifera ) colonies are declining, and a number of stressors have been identified that affect, alone or in combination, the health of honey bees. The ectoparasitic Mite Varroa destructor , honey bee viruses that are often closely associated with the Mite, and pesticides used to control the Mite population form a complex system of stressors that may affect honey bee health in different ways. During an acaricide treatment using Apistan (plastic strips coated with tau-fluvalinate), we analyzed the infection dynamics of deformed wing virus (DWV), sacbrood virus (SBV), and black queen cell virus (BQCV) in adult bees, Mite-infested pupae, their associated Varroa Mites, and uninfested pupae, comparing these to similar samples from untreated control colonies. Titers of DWV increased initially with the onset of the acaricide application and then slightly decreased progressively coinciding with the removal of the Varroa Mite Infestation. This initial increase in DWV titers suggests a physiological effect of tau-fluvalinate on the host's susceptibility to viral infection. DWV titers in adult bees and uninfested pupae remained higher in treated colonies than in untreated colonies. The titers of SBV and BQCV did not show any direct relationship with Mite Infestation and showed a variety of possible effects of the acaricide treatment. The results indicate that other factors besides Varroa Mite Infestation may be important to the development and maintenance of damaging DWV titers in colonies. Possible biochemical explanations for the observed synergistic effects between tau-fluvalinate and virus infections are discussed.

Giseli Buffon - One of the best experts on this subject based on the ideXlab platform.

  • oryza sativa cv nipponbare and oryza barthii as unexpected tolerance and susceptibility sources against schizotetranychus oryzae acari tetranychidae Mite Infestation
    Frontiers in Plant Science, 2021
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Amanda Azevedo Bertolazi, Vanildo Silveira, Mara Cristina Barbosa Lopes, Raul Antonio Sperotto
    Abstract:

    Cultivated rice (Oryza sativa L.) is frequently exposed to multiple stresses, including Schizotetranychus oryzae Mite Infestation. Rice domestication has narrowed the genetic diversity of the species, leading to a wide susceptibility. This work aimed to analyze the response of two African rice species (Oryza barthii and Oryza glaberrima), weedy rice (O. sativa f. spontanea), and O. sativa cv. Nipponbare to S. oryzae Infestation. Surprisingly, leaf damage, histochemistry, and chlorophyll concentration/fluorescence indicated that the African species present a higher level of leaf damage, increased accumulation of H2O2, and lower photosynthetic capacity when compared to O. sativa plants under infested conditions. Infestation decreased tiller number, except in Nipponbare, and caused the death of O. barthii and O. glaberrima plants during the reproductive stage. While Infestation did not affect the weight of 1,000 grains in both O. sativa, the number of panicles per plant was affected only in O. sativa f. spontanea, and the percentage of full seeds per panicle and seed length were increased only in Nipponbare. Using proteomic analysis, we identified 195 differentially abundant proteins when comparing susceptible (O. barthii) and tolerant (Nipponbare) plants under control and infested conditions. O. barthii presents a less abundant antioxidant arsenal and is unable to modulate proteins involved in general metabolism and energy production under infested condition. Nipponbare presents high abundance of detoxification-related proteins, general metabolic processes, and energy production, suggesting that the primary metabolism is maintained more active compared to O. barthii under infested condition. Also, under infested conditions, Nipponbare presents higher levels of proline and a greater abundance of defense-related proteins, such as osmotin, ricin B-like lectin, and protease inhibitors (PIs). These differentially abundant proteins can be used as biotechnological tools in breeding programs aiming at increased tolerance to Mite Infestation.

  • nipponbare and wild rice species as unexpected tolerance and susceptibility sources against schizotetranychus oryzae acari tetranychidae Mite Infestation
    bioRxiv, 2020
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Amanda Azevedo Bertolazi, Vanildo Silveira, Mara Cristina Barbosa Lopes, Raul Antonio Sperotto
    Abstract:

    Cultivated rice (Oryza sativa L.) is frequently exposed to multiple stresses, including Schizotetranychus oryzae Mite Infestation. Rice domestication has narrowed the genetic diversity of the species, reducing the stress resistance and leading to a wide susceptibility. Therefore, wild rice species present an alternative to search for this lost variability. Aiming to observe the response of two wild rice species (Oryza barthii and Oryza glaberrima) and two Oryza sativa genotypes (cv. Nipponbare and O. sativa f. spontanea) to S. oryzae Infestation, we used agronomic, physiological and molecular analyses. Surprisingly, analyses of leaf damage, histochemistry, chlorophyll concentration and chlorophyll fluorescence showed that the wild species present higher level of leaf damage, increased accumulation of H2O2 and lower photosynthetic capacity when compared to O. sativa genotypes under infested conditions. Infestation did not affect plant height, but decreased tiller number, except in cv. Nipponbare, whose development was not affected. Infestation also caused the death of wild plants during the reproductive stage, unlike O. sativa genotypes, which were able to tolerate stress and produce seeds. While Infestation did not affect the weight of 1,000 grains in both O. sativa genotypes, the number of panicles per plant was affected only in O. sativa f. spontanea, and the percentage of full seeds per panicle and seed length were increased only in cv. Nipponbare. Proteomic analysis allowed us to identify 195 differentially abundant proteins when comparing susceptible (O. barthii) and tolerant (O. sativa cv. Nipponbare) genotypes under control and infested conditions. We found that O. barthii has a less abundant antioxidant arsenal. In addition, it is unable to modulate proteins involved with general metabolism and energy production under infested condition. In Nipponbare we found high abundance of detoxification-related proteins, general metabolic processes and energy production, which allows us to suggest that, under infested condition, the primary metabolism is maintained more active compared to O. barthii. Also, Nipponbare presents a greater abundance of defense-related proteins, such as osmotin, ricin B-like lectin, and protease inhibitors of the Bowman Birk trypsin inhibitor family, as well as higher levels of the compatible osmolyte Proline under infested condition. Identification of these differentially abundant proteins can be used as an important biotechnological tool in breeding programs that aim increased tolerance to phytophagous Mite Infestation.

  • unraveling rice tolerance mechanisms against schizotetranychus oryzae Mite Infestation
    bioRxiv, 2018
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Angie Geraldine Sierra Rativa, Rodrigo Gastmann, Angelo Schuabb Heringer, Vanildo Silveira
    Abstract:

    Infestation of Schizotetranychus oryzae (Acari: Tetranychidae) causes great losses in rice productivity. Infestation in Puita INTA-CL cultivar reduced the number of seeds/plant, percentage of full seeds, 1,000 seeds weight, and seed length, whereas Infestation in IRGA423 increased 1,000 seeds weight and seed length. Reduction in seed weight/plant caused by Infestation was higher in Puita INTA-CL than IRGA423. Thus, Puita INTA-CL was established as susceptible, and IRGA423 as tolerant to S. oryzae Infestation. Photosynthetic parameters were less affected by Infestation in IRGA423 than in Puita INTA-CL. Infestation also caused accumulation of H2O2, decreased cell membrane integrity and accelerated senescence in leaves of Puita INTA-CL, while leaves of IRGA423 presented higher levels of phenolics compounds. Using proteomic analysis, we identified proteins related to plant defense, such as jasmonate synthesis, and related to other mechanisms of tolerance such as oxidative stress, photosynthesis, and DNA structure maintenance, more abundant in IRGA423 after seven days of Infestation. We detected higher levels of silicon (as amorphous silica cells) in leaves of infested IRGA423 plants compared to Puita INTA-CL, an element previously linked to plant defense. Our data shows that IRGA423 presents tolerance to S. oryzae Infestation, and that multiple mechanisms might be employed by this cultivar.

  • Unraveling Rice Tolerance Mechanisms Against Schizotetranychus oryzae Mite Infestation
    Frontiers Media S.A., 2018
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Angie Geraldine Sierra Rativa, Rodrigo Gastmann, Angelo Schuabb Heringer
    Abstract:

    Rice is the staple food for over half of the world’s population. Infestation of Schizotetranychus oryzae (Acari: Tetranychidae) causes great losses in rice productivity. To search for rice genotypes that could better tolerate S. oryzae Infestation, we evaluated morphological and production parameters in Brazilian cultivars, and identified two cultivars with contrasting responses. Leaf damage during Infestation was similar for all cultivars. However, Infestation in Puitá INTA-CL resulted in reduction in the number of seeds per plant, percentage of full seeds, weight of 1,000 seeds, and seed length, whereas Infestation in IRGA 423 increased weight of 1,000 seeds and seed length. Reduction in seed weight per plant caused by Infestation was clearly higher in Puitá INTA-CL (62%) compared to IRGA 423 (no reduction detected), thus Puitá INTA-CL was established as susceptible, and IRGA 423 as tolerant to S. oryzae Infestation. Photosynthetic parameters were less affected by Infestation in IRGA 423 than in Puitá INTA-CL, evidencing higher efficiency of energy absorption and use. S. oryzae Infestation also caused accumulation of H2O2, decreased cell membrane integrity (indicative of cell death), and accelerated senescence in leaves of Puitá INTA-CL, while leaves of IRGA 423 presented higher levels of total phenolics compounds. We performed proteomics analysis of Puitá INTA-CL and IRGA 423 leaves after 7 days of Infestation, and identified 60 differentially abundant proteins (28 more abundant in leaves of Puitá INTA-CL and 32 in IRGA 423). Proteins related to plant defense, such as jasmonate synthesis, and related to other mechanisms of tolerance such as oxidative stress, photosynthesis, and DNA structure maintenance, together with energy production and general metabolic processes, were more abundant in IRGA 423. We also detected higher levels of silicon (as amorphous silica cells) in leaves of infested IRGA 423 plants compared to Puitá INTA-CL, an element previously linked to plant defense, indicating that it could be involved in tolerance mechanisms. Taken together, our data show that IRGA 423 presents tolerance to S. oryzae Infestation, and that multiple mechanisms might be employed by this cultivar. These findings could be used in biotechnological approaches aiming to increase rice tolerance to Mite Infestation

Marcel Dicke - One of the best experts on this subject based on the ideXlab platform.

  • effect of sequential induction by mamestra brassicae l and tetranychus urticae koch on lima bean plant indirect defense
    Journal of Chemical Ecology, 2014
    Co-Authors: Tila R Menzel, Rieta Gols, Tzeyi Huang, Berhane T Weldegergis, Joop J A Van Loon, Marcel Dicke
    Abstract:

    Attack by multiple herbivores often leads to modification of induced plant defenses compared to single herbivory, yet little is known about the effects on induced indirect plant defense. Here, we investigated the effect of sequential induction of plant defense by Mamestra brassicae caterpillar oral secretion and an Infestation by Tetranychus urticae spider Mites on the expression of indirect plant defense in Lima bean plants. The effect on indirect defense was assessed using behavior assays with the specialist predatory Mite Phytoseiulus persimilis in an olfactometer, headspace analysis of 11 major herbivore-induced plant volatiles (HIPVs) including (E)-β-ocimene, and transcript levels of the corresponding gene Phaseolus lunatus (E)-β-ocimene synthase (PlOS). Predatory Mites were found to distinguish between plants induced by spider Mites and caterpillar oral secretion but not between plants with single spider Mite Infestation and plants induced by caterpillar oral secretion prior to spider Mite Infestation. Indeed, the volatile blends emitted by plants induced by spider Mites only and the sequential induction treatment of caterpillar oral secretion followed by spider Mite Infestation, were similar. Our results suggest that plant indirect defense is not affected by previous treatment with oral secretion of M. brassicae caterpillars.

  • induction of direct and indirect plant responses by jasmonic acid low spider Mite densities or a combination of jasmonic acid treatment and spider Mite Infestation
    Journal of Chemical Ecology, 2003
    Co-Authors: Rieta Gols, Mara Roosjen, H Dijkman, Marcel Dicke
    Abstract:

    Jasmonic acid (JA) and the octadecanoid pathway are involved in both induced direct and induced indirect plant responses. In this study, the herbivorous Mite, Tetranychus urticae, and its predator, Phytoseiulus persimilis, were given a choice between Lima bean plants induced by JA or spider Mites and uninduced control plants. Infestation densities resulting in the induction of predator attractants were much lower than thus far assumed, i.e., predatory Mites were significantly attracted to plants that were infested for 2 days with only one or four spider Mites per plant. Phytoseiulus persimilis showed a density-dependent response to volatiles from plants that were infested with different numbers of spider Mites. Similarly, treating plants with increasing concentrations of JA also led to increased attraction of P. persimilis. Moreover, the duration of spider Mite Infestation was positively correlated with the proportion of predators that were attracted to Mite-infested plants. A pretreatment of the plants with JA followed by a spider Mite Infestation enhanced the attraction of P. persimilis to plant volatiles compared to attraction to volatiles from plants that were only infested with spider Mites and did not receive a pretreatment with JA. The herbivore, T. urticae preferred leaf tissue that previously had been infested with conspecifics to uninfested leaf tissue. In the case of choice tests with JA-induced and control leaf tissue, spider Mites slightly preferred control leaf tissue. When spider Mites were given a choice between leaf discs induced by JA and leaf discs damaged by spider Mite feeding, they preferred the latter. The presence of herbivore induced chemicals and/or spider Mite products enhanced settlement of the Mites, whereas treatment with JA seemed to impede settlement.

Felipe Klein Ricachenevsky - One of the best experts on this subject based on the ideXlab platform.

  • oryza sativa cv nipponbare and oryza barthii as unexpected tolerance and susceptibility sources against schizotetranychus oryzae acari tetranychidae Mite Infestation
    Frontiers in Plant Science, 2021
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Amanda Azevedo Bertolazi, Vanildo Silveira, Mara Cristina Barbosa Lopes, Raul Antonio Sperotto
    Abstract:

    Cultivated rice (Oryza sativa L.) is frequently exposed to multiple stresses, including Schizotetranychus oryzae Mite Infestation. Rice domestication has narrowed the genetic diversity of the species, leading to a wide susceptibility. This work aimed to analyze the response of two African rice species (Oryza barthii and Oryza glaberrima), weedy rice (O. sativa f. spontanea), and O. sativa cv. Nipponbare to S. oryzae Infestation. Surprisingly, leaf damage, histochemistry, and chlorophyll concentration/fluorescence indicated that the African species present a higher level of leaf damage, increased accumulation of H2O2, and lower photosynthetic capacity when compared to O. sativa plants under infested conditions. Infestation decreased tiller number, except in Nipponbare, and caused the death of O. barthii and O. glaberrima plants during the reproductive stage. While Infestation did not affect the weight of 1,000 grains in both O. sativa, the number of panicles per plant was affected only in O. sativa f. spontanea, and the percentage of full seeds per panicle and seed length were increased only in Nipponbare. Using proteomic analysis, we identified 195 differentially abundant proteins when comparing susceptible (O. barthii) and tolerant (Nipponbare) plants under control and infested conditions. O. barthii presents a less abundant antioxidant arsenal and is unable to modulate proteins involved in general metabolism and energy production under infested condition. Nipponbare presents high abundance of detoxification-related proteins, general metabolic processes, and energy production, suggesting that the primary metabolism is maintained more active compared to O. barthii under infested condition. Also, under infested conditions, Nipponbare presents higher levels of proline and a greater abundance of defense-related proteins, such as osmotin, ricin B-like lectin, and protease inhibitors (PIs). These differentially abundant proteins can be used as biotechnological tools in breeding programs aiming at increased tolerance to Mite Infestation.

  • nipponbare and wild rice species as unexpected tolerance and susceptibility sources against schizotetranychus oryzae acari tetranychidae Mite Infestation
    bioRxiv, 2020
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Amanda Azevedo Bertolazi, Vanildo Silveira, Mara Cristina Barbosa Lopes, Raul Antonio Sperotto
    Abstract:

    Cultivated rice (Oryza sativa L.) is frequently exposed to multiple stresses, including Schizotetranychus oryzae Mite Infestation. Rice domestication has narrowed the genetic diversity of the species, reducing the stress resistance and leading to a wide susceptibility. Therefore, wild rice species present an alternative to search for this lost variability. Aiming to observe the response of two wild rice species (Oryza barthii and Oryza glaberrima) and two Oryza sativa genotypes (cv. Nipponbare and O. sativa f. spontanea) to S. oryzae Infestation, we used agronomic, physiological and molecular analyses. Surprisingly, analyses of leaf damage, histochemistry, chlorophyll concentration and chlorophyll fluorescence showed that the wild species present higher level of leaf damage, increased accumulation of H2O2 and lower photosynthetic capacity when compared to O. sativa genotypes under infested conditions. Infestation did not affect plant height, but decreased tiller number, except in cv. Nipponbare, whose development was not affected. Infestation also caused the death of wild plants during the reproductive stage, unlike O. sativa genotypes, which were able to tolerate stress and produce seeds. While Infestation did not affect the weight of 1,000 grains in both O. sativa genotypes, the number of panicles per plant was affected only in O. sativa f. spontanea, and the percentage of full seeds per panicle and seed length were increased only in cv. Nipponbare. Proteomic analysis allowed us to identify 195 differentially abundant proteins when comparing susceptible (O. barthii) and tolerant (O. sativa cv. Nipponbare) genotypes under control and infested conditions. We found that O. barthii has a less abundant antioxidant arsenal. In addition, it is unable to modulate proteins involved with general metabolism and energy production under infested condition. In Nipponbare we found high abundance of detoxification-related proteins, general metabolic processes and energy production, which allows us to suggest that, under infested condition, the primary metabolism is maintained more active compared to O. barthii. Also, Nipponbare presents a greater abundance of defense-related proteins, such as osmotin, ricin B-like lectin, and protease inhibitors of the Bowman Birk trypsin inhibitor family, as well as higher levels of the compatible osmolyte Proline under infested condition. Identification of these differentially abundant proteins can be used as an important biotechnological tool in breeding programs that aim increased tolerance to phytophagous Mite Infestation.

  • unraveling rice tolerance mechanisms against schizotetranychus oryzae Mite Infestation
    bioRxiv, 2018
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Angie Geraldine Sierra Rativa, Rodrigo Gastmann, Angelo Schuabb Heringer, Vanildo Silveira
    Abstract:

    Infestation of Schizotetranychus oryzae (Acari: Tetranychidae) causes great losses in rice productivity. Infestation in Puita INTA-CL cultivar reduced the number of seeds/plant, percentage of full seeds, 1,000 seeds weight, and seed length, whereas Infestation in IRGA423 increased 1,000 seeds weight and seed length. Reduction in seed weight/plant caused by Infestation was higher in Puita INTA-CL than IRGA423. Thus, Puita INTA-CL was established as susceptible, and IRGA423 as tolerant to S. oryzae Infestation. Photosynthetic parameters were less affected by Infestation in IRGA423 than in Puita INTA-CL. Infestation also caused accumulation of H2O2, decreased cell membrane integrity and accelerated senescence in leaves of Puita INTA-CL, while leaves of IRGA423 presented higher levels of phenolics compounds. Using proteomic analysis, we identified proteins related to plant defense, such as jasmonate synthesis, and related to other mechanisms of tolerance such as oxidative stress, photosynthesis, and DNA structure maintenance, more abundant in IRGA423 after seven days of Infestation. We detected higher levels of silicon (as amorphous silica cells) in leaves of infested IRGA423 plants compared to Puita INTA-CL, an element previously linked to plant defense. Our data shows that IRGA423 presents tolerance to S. oryzae Infestation, and that multiple mechanisms might be employed by this cultivar.

  • Unraveling Rice Tolerance Mechanisms Against Schizotetranychus oryzae Mite Infestation
    Frontiers Media S.A., 2018
    Co-Authors: Giseli Buffon, Edina Aparecida Dos Reis Blasi, Thaina Ines Lamb, Janete Mariza Adamski, Joseli Schwambach, Felipe Klein Ricachenevsky, Angie Geraldine Sierra Rativa, Rodrigo Gastmann, Angelo Schuabb Heringer
    Abstract:

    Rice is the staple food for over half of the world’s population. Infestation of Schizotetranychus oryzae (Acari: Tetranychidae) causes great losses in rice productivity. To search for rice genotypes that could better tolerate S. oryzae Infestation, we evaluated morphological and production parameters in Brazilian cultivars, and identified two cultivars with contrasting responses. Leaf damage during Infestation was similar for all cultivars. However, Infestation in Puitá INTA-CL resulted in reduction in the number of seeds per plant, percentage of full seeds, weight of 1,000 seeds, and seed length, whereas Infestation in IRGA 423 increased weight of 1,000 seeds and seed length. Reduction in seed weight per plant caused by Infestation was clearly higher in Puitá INTA-CL (62%) compared to IRGA 423 (no reduction detected), thus Puitá INTA-CL was established as susceptible, and IRGA 423 as tolerant to S. oryzae Infestation. Photosynthetic parameters were less affected by Infestation in IRGA 423 than in Puitá INTA-CL, evidencing higher efficiency of energy absorption and use. S. oryzae Infestation also caused accumulation of H2O2, decreased cell membrane integrity (indicative of cell death), and accelerated senescence in leaves of Puitá INTA-CL, while leaves of IRGA 423 presented higher levels of total phenolics compounds. We performed proteomics analysis of Puitá INTA-CL and IRGA 423 leaves after 7 days of Infestation, and identified 60 differentially abundant proteins (28 more abundant in leaves of Puitá INTA-CL and 32 in IRGA 423). Proteins related to plant defense, such as jasmonate synthesis, and related to other mechanisms of tolerance such as oxidative stress, photosynthesis, and DNA structure maintenance, together with energy production and general metabolic processes, were more abundant in IRGA 423. We also detected higher levels of silicon (as amorphous silica cells) in leaves of infested IRGA 423 plants compared to Puitá INTA-CL, an element previously linked to plant defense, indicating that it could be involved in tolerance mechanisms. Taken together, our data show that IRGA 423 presents tolerance to S. oryzae Infestation, and that multiple mechanisms might be employed by this cultivar. These findings could be used in biotechnological approaches aiming to increase rice tolerance to Mite Infestation