Abstract
Rice plants release proton (H+) from root cells into rhizosphere area leading to the acidification of the rhizosphere and increased solubility of ferric iron complexes on the cell membrane, which is important for iron uptakes. Here, we present a detailed protocol to measure H+ flux in root hairs of transgenic rice seedlings and transgenic rice protoplasts by the Non-invasive Micro-test Technique (NMT). The NMT system is based on a non-invasive microelectrode technology that is automatically controlled by a computer, to achieve a three-dimensional, real-time, dynamic characterization of the concentration, velocity, and direction of a variety of molecules or ions. Because there is no need to directly contact the measured cells that could cause cell damage, we are able to obtain accurate and real time information on ion concentration. This is the first protocol that describes the non-invasive micro measurement technique of both root hairs and protoplasts in rice. In NMT, voltage differences are measured at two excursion points that are manipulated using a computer. Voltage differences can be converted into H+ fluxes using the ASET 2.0 (The imFlux® software) and JCal v3.2.1 Software. Analysis of the H+ fluxes provides a simultaneous measure of the crossing of a localized region of the root surface in response to stress, which provides real-time in-situ detection of net ion transport across membranes. This method will promote use of NMT in plant biology.
Keywords: Proton flux, Non-invasive Micro-test Technique (NMT), Rice, Microelectrode
Materials and Reagents
Equipment
Software
Procedure
Recipes
Acknowledgments
The protocol was adapted from our previously published paper Li et al. (2015). We wish to thank Younger USA (Xuyue, Beijing) NMT Service Center for technical support. This study was supported by the National Natural Science foundation of China (Grant Nos. 30770178 and 30971856), Beijing Municipal National Science Foundation Key Fund Projects (B) (Grant No. KZ200710028013), Beijing Municipal National Science Foundation (No. 5042004), and the Seventh Beijing Municipal Outstanding Teacher Award (2011).
References
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