Browsing by Author "Inostroza-Blancheteau, Claudio"

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    Biochemical and molecular changes in response to aluminium-stress in highbush blueberry (Vaccinium corymbosum L.)
    (2011) Inostroza-Blancheteau, Claudio; Reyes-Diaz, Marjorie; Aquea, Felipe; Nunes-Nesi, Adriano; Alberdi, Miren; Arce-Johnson, Patricio
    Aluminium (Al) stress is an important factor limiting crop yields in acid soils. Despite this, very little is known about the mechanisms of resistance to this stress in woody plants. To understand the mechanisms of Al-toxicity and response in blueberries, we compared the impact of AI-stress in Al-resistant and AI-sensitive genotypes using Vaccinium corymbosum L. (Ericaceae) as a plant model. We investigated the effect of Al-stress on the physiological performance, oxidative metabolism and expression of genes that encode antioxidant enzymes in two V. corymbosum cultivars maintained hydroponically with AlCl3 (0 and 100 mu M). Microscopic analyses of AI-treated root tips suggested a higher degree of Al-induced morphological injury in Bluegold (sensitive genotype) compared to Brigitta (resistant genotype). Furthermore, the results indicated that Brigitta had a greater ability to control oxidative stress under Al-toxicity, as reflected by enhancement of several antioxidative and physiological properties (radical scavenging activity: RSA, superoxide dismutase: SOD and catalase: CAT; maximum quantum yield: Fv/Fm, effective quantum yield: 04)511, electron transport rate: ETR and non-photochemical quenching: NPQ). Finally, we analyzed the expression of genes homologous to GST and ALDH, which were identified in a global expression analysis. In the resistant genotype, the expression of these genes in response to Al-stress was greater in leaves than in roots. (C) 2011 Elsevier Masson SAS. All rights reserved.
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    Characterization of physiological and antioxidant responses in Run1Ren1 Vitis vinifera plants during Erysiphe necator attack
    (2022) Sosa-Zuniga, Viviana; Martinez-Barradas, Vera; Espinoza, Carmen; Tighe-Neira, Ricardo; Vidal Valenzuela, Alvaro; Inostroza-Blancheteau, Claudio; Arce-Johnson, Patricio
    Grapevine is a fruit crop of major significance worldwide. Fungal attacks are one of the most relevant factors affecting grapevine yield and fruit quality, and powdery mildew caused by Erysiphe necator is one of the most harmful fungal diseases for this fruit-bearing species. Incorporating resistance genes such as Run1 and Ren1 in new vine selections offers a sustainable alternative to control the disease. These combined loci produce an immune response that prevents the development of the disease. However, to date studies are lacking concerning whether this response generates alterations in the physiological and antioxidant parameters of resistant plants in the presence of the fungus or if it has an associated energy cost. Therefore, the main goal of our research was to determine if Run1Ren1 plants present alterations in their physiological and biochemical parameters in the presence of the fungus. To achieve this target, a previously characterized resistant Run1Ren1 genotype and the susceptible Carmenere cultivar were analyzed. We evaluated photochemical parameters (Fv'/Fm', phi PSII and ETR), net photosynthesis (Pn), photosynthetic pigments, transpiration (E), stomatal conductance (g(s)), oxidative stress parameters (MDA), antioxidant activity, and phenols. Our results show that the physiological parameters of Run1Ren1 plants were not negatively affected by the fungus at 10 days post-inoculation, contrasting with alterations observed in the susceptible plants. Therefore, we propose that the resistance response triggered by Run1Ren1 is physiologically and biochemically advantageous to grapevines by preventing the development of powdery mildew infection.
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    Drought Tolerance Evaluation of 'Zorzal,' the Most Cultivated Common Bean in Chile, a Country Facing Desertification
    (2024) Martinez-Barradas, Vera; Inostroza-Blancheteau, Claudio; Tighe-Neira, Ricardo; Romero-Romero, Jesus Lucina; Schwember, Andres R.; Arce-Johnson, Patricio
    During the last decades, water distribution around the globe has been affected by climate change. Particularly, in Chile, the last decade has been marked by a mega-drought period, which has severely impacted agriculture. In this scenario, common bean (Phaseolus vulgaris L.) has been seriously affected due to its dependence on irrigation. In this work, we studied how 'Zorzal,' the most sown cultivar in Chile copes with drought stress and the mechanisms used to deal with it. A greenhouse experiment was performed during the 2019-2020 growing season. Plants were subjected to a severe drought stress suspending irrigation at the pre-flowering stage. Photosynthetic parameters, chlorophyll concentration, relative leaf water content (RWC) and lipid peroxidation were analyzed at 7 and 21 days after water suspension, yield was analyzed at the end of the growing season, and those parameters were compared to a susceptible cultivar of the same gene pool 'Arroz Tuscola.' 'Zorzal' stood out for having diverse treats associated with drought tolerance, as maintaining stable RWC during drought stress, a better reactive oxygen species scavenging system than 'Arroz Tuscola,' and stable root biomass during the drought condition. However, seed production was significantly reduced. Our results evidence that 'Zorzal,' the most widely cultivated cultivar of common bean in Chile, has good physiological and anatomical treats for plant survivance under drought stress conditions. However, our study suggests that these characteristics may not be enough to maintain a stable seed production.
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    RESISTANCE MECHANISMS OF ALUMINUM (Al3+) PHYTOTOXICITY IN CEREALS: PHYSIOLOGICAL, GENETIC AND MOLECULAR BASES
    (2008) Inostroza-Blancheteau, Claudio; Soto, Braulio; Ulloa, Pilar; Aquea, Felipe; Reyes-Diaz, Marjorie
    Aluminum (Al) toxicity is one of the main factors limiting crop productivity in acid soils around the world. In cereals, this problem can affect between 30 and 40% of crop yields. One way to reduce the toxic effect of Al is to neutralize the acidity with calcareous amendments. However, this practice is demanding and not very effective. An alternative is the search for genetic variability in the genome of cropping grasses and/or their wild relatives to resist Al. The development of biotechnology and molecular genetics approach has facilitated the understanding of the physiological, genetic and molecular bases in the process of ameliorating these species. This review presents the main physiological mechanisms of Al resistance and the genetic and molecular bases that explain the degree of resistance between different cereals species.