Respuestas al estrés por calor en los cultivos. I. Aspectos moleculares, bioquímicos y siológicos.

Abstract

RESUMENEl objetivo de esta revisión fue integrar los mecanismos por los cuales las plantas responden al estrés por calor a lo largo del continuo suelo-planta-atmósfera, desde una perspectiva agronómica. Esta revisión presenta las bases fisiológicas del estrés por calor, para lo cual se examinaron las temperaturas óptimas y los umbrales de estrés por calor en los cultivos, las metodologías para su estudio, y las respuestas moleculares, bioquímicas y fisiológicas de las plantas a altas temperaturas. Se describe el efecto de las altas temperaturas sobre la estructura y el metabolismo celular, la respiración y la aclimatación de la Q 10 , la estabilidad de las membranas, la acumulación de osmolitos compatibles, la producción de pigmentos y metabolitos secundarios, la producción de especies reactivas de oxígeno (ROS) y enzimas antioxidantes, la producción de proteínas de estrés, y el efecto sobre la fotosíntesis y la partición de asimilados. Además, se discuten los cambios hormonales que regulan la respuesta de las plantas en el campo, su señalización y la aclimatación al estrés térmico.Palabras clave: enzimas antioxidantes, osmolitos compatibles, proteínas de choque térmico, termotolerancia inducida. ABSTRACTThe objective of this review was to integrate the mechanisms by which plants respond to high temperature stress along the soil-plant-atmosphere continuum, from an agronomic perspective. The review presents the physiological basis underlying thermal stress, for which the optimum and threshold temperatures of crops are examined, along with methodologies for its study and the molecular, biochemical and physiological responses of plants to high temperature. The effects of high temperatures on cell ultrastructure and metabolism, respiration, the acclimation of Q 10 , membrane stability, accumulation of compatible osmolites, production of pigments, secondary metabolites and stress proteins, production of reactive oxygen species (ROS) and antioxidant enzymes, and the effects on photosynthesis and assimilate partitioning are examined. Hormonal changes and signaling regulating plant responses in the field, and the acclimation to temperature stress are also discussed.

Description of the antioxidant capacity of Calafate berries (Berberis microphylla) collected in southern Chile

“…The consumption of these compounds has been proposed as a method of protection against diseases (Yu et al, 2016), and may act as exogenous agents capable of protecting the cell from oxidative damage (Hostetler et al, 2017), However, their synthesis may be influenced by abiotic stress, corresponding to environmental factors such as temperature, humidity and/or ultraviolet radiation, to which the bush is subjected during its growth (Liu et al, 2017;Khoo et al, 2017). Studies on plant food sources have shown that exposure to different abiotic stressors increase anthocyanin concentrations (Li et al, 2018;Altangerel et al, 2017;Chavez-Barrantes & Gutiérrez-Soto, 2017), which may be due to the specific role that these compounds play in the plant during abiotic stress, such as ROS cooling, photoprotection, stress signaling and/or xenohormesis (Kovinich et al, 2015). The objective of this study was to compare the antioxidant capacity of Calafate collected at different locations in southern Chile, specifically Aysén and Magallanes.…”

Effects of Light Intensity and Water Stress on Growth, Photosynthetic Characteristics and Plant Survival of Cistus heterophyllus Desf. Subsp. carthaginensis (Pau) M. B. Crespo & Mateo

“…When stomata are closed by stress induced by factors such as high radiation, heat or drought, the dissipation of radiation in the form of latent heat is reduced and the temperature of the leaf rises in a vicious circle [37]. If the stress is prolonged over time, the integrity of photosystem II is compromised due to the stacking of thylakoid membranes, thus reducing the photosynthetic efficiency [38].…”

Effect of Ozonated Fertigation in Pepper Cultivation under Greenhouse Conditions

“…Under stress conditions such as high temperature [30], waterlogging [31], salinity [32], and hydric and nutrient deficiencies [25], plants must change their physiology and increase their efficiency so as to use few nutrients available to fulfill their development cycles as occurs under O 0 .…”