Whole-Plant Measure of Temperature-Induced Changes in the Cytosolic pH of Potato Plants Using Genetically Encoded Fluorescent Sensor Pt-GFP

Abstract

Cytosolic pH (pHcyt) regulates a wide range of cellular processes in plants. Changes in pHcyt occurring under the effect of different stressors can participate in signal transmission. The dynamics of pHcyt under the action of external factors, including significant factors for open ground crops such as temperature, remains poorly understood, which is largely due to the difficulty of intracellular pH registration using standard methods. In this work, model plants of potato (one of the essential crops) expressing a fluorescent ratiometric pH sensor Pt-GFP were created. The calibration obtained in vivo allowed for the determination of the pHcyt values of the cells of the leaves, which is 7.03 ± 0.03 pH. Cooling of the whole leaf caused depolarization and rapid acidification of the cytosol, the amplitude of which depended on the cooling strength, amounting to about 0.2 pH units when cooled by 15 °C. When the temperature rises to 35–40 °C, the cytosol was alkalized by 0.2 pH units. Heating above the threshold temperature caused the acidification of cytosol and generation of variation potential. The observed rapid changes in pHcyt can be associated with changes in the activity of H+-ATPases, which was confirmed by inhibitory analysis.

The Morphological Parameters and Cytosolic pH of Cells of Root Zones in Tobacco Plants (Nicotiana tabacum L.): Nonlinear Effects of NaCl Concentrations

“…pHcyt may also change under the influence of stressors. For instance, cytosolic acidification has been observed in response to stressors such as low temperatures [22,23] and pathogens [24]. On the other hand, cytosolic alkalinization has been demonstrated during gravitropic reactions and drought [16].…”

“…The presence of fluorescent proteins in the cytosol also enables the visualization of cell morphology and different tissue types without the need for histological staining. Pt-GFP, a widely used genetically encoded ratiometric pH sensor [23,26,27,29,[35][36][37], boasts a broad pH sensitivity range (pH 4.5-8.5), exceptional acid stability, and insensitivity to salinity [26]. In this study, we employed transgenic tobacco plants expressing a pH-sensitive sensor Pt-GFP to investigate how salinity affects pHcyt in root cells.…”

Phase separation and molecular ordering of the prion-like domain of the Arabidopsis thermosensory protein EARLY FLOWERING 3

“…The pH sensitivity observed in vitro may also relate to the thermosensory activity of the protein, although this is speculative. As the temperature of a solution increases, the pH will decrease and there is evidence that this occurs intracellularly, albeit with proton pumps acting to buffer these pH changes ( 46 , 47 ). A decrease in pH favors LLPS of ELF3 PrLD, for both the untagged and GFP fused PrLD and this may be true for ELF3 in complex with different protein partners, whose activity will vary due to transition from a mobile dilute phase, to a concentrated liquid phase and eventually to an “aged” low-mobility phase.…”

Impact of Delayed Cooling and Precooling Parameters on Physical Properties of Potatoes: A Storage Study

“…pH is an important quality parameter and can be used to understand various enzymatic functions and other processes occurring at a cellular level (Pecherina et al, 2021). A representative sample was washed, peeled, and then ground in a juicer.…”