Sinais elétricos em microtomateiros mutantes em ABA: aspectos eletrofisiológicos e metabólicos sob diferentes condições hídricas

Abstract

Electrical signals in ABA mutant microtomatos: electrophysiological and metabolic aspects under different water conditions Research on plant signaling has traditionally focused on the role of phytohormones, calcium waves and reactive oxygen species as long-distance signaling molecules. However, it is known that plants have the ability to generate electrical signals necessary for intra and intercellular communications in response to different environmental factors, such as light, injuries, water stress and photoperiodism. However, it is not yet clear whether electrical communication is linked to the presence of other signaling pathways such as the abscisic acid pathway, or whether, during periods of stress, such as water deficit, metabolic adjustment is related to the generation of electrical signals after rehydration of the plants. Therefore, the objective of this work was to characterize the electrical signals generated in plants of mutant tomato plants in abscisic acid and to identify the electrophysiological and metabolic changes that are associated with the propagation of electrical signals in response to drought and the rehydration stimulus in these plants. Therefore, the objective of this work was to characterize the electrical signals generated in plants of mutant tomato plants in abscisic acid and to identify the electrophysiological and metabolic changes that are associated with the propagation of electrical signals in response to drought and the rehydration stimulus in these plants. Three independent studies were carried out to evaluate the generation of electrical signals in microtomatoes, cultivar Micro-Tom (MT) of the wild type (MTwt) and of the isogenic mutants MTnotabilis (MTnot) and transgenic MTsp12::NCED (MTNCED). The first study evaluated which electrical signals are spontaneously generated and evoked via electrical stimulus. The second and third studies were carried out to evaluate the effect of water deficit and the rehydration stimulus on gas exchange, metabolism and the generation of action potentials in microtomatoes and also the effect of electrical signals on physiological responses. Spontaneous action potentials were observed more frequently in MTnot compared to MTwt and MTNCED. On the other hand, spontaneous variation potentials occurred more frequently in MTNCED, demonstrating that ABA influences signal propagation. In addition, the plants exposed to water deficit induced an increasing depolarization of the electrical potential of the plasma membrane in MTwt and MTnot, which contributed to the generation of action potentials after the application of the rehydration stimulus. In MTwt, the electrical signal induced an increase in photosynthetic rate, stomatal conductance and transpiration. In contrast, gas exchange traits were reduced in ABA mutants. Additionally, the higher levels of glutamic acid, asparagine and GABA under water deficit may have influenced the induction and propagation of the electrical signal in MTnot.

Abscisic acid, and abscisic acid-induced water stress tolerance in mycorrhizal herbaceous and olive (Olea europaea) plants

“…It is then transported via vascular tissues, and it shows responses in a variety of cells, such as guard cells and others (Postiglione & Muday, 2020). ABA must be translocated from the cells where it is synthesized via intercellular transport into the neighboring tissues (Silva, 2020). As a weak acid, ABA is a charged anion (i.e., ABA -) in the cytoplasm (pH 7).…”