TY  - JOUR
A1  - Zhou, Yang
A1  - Ding, Meiqi
A1  - Duan, Xiaodong
A1  - Konrad, Kai R.
A1  - Nagel, Georg
A1  - Gao, Shiqiang
T1  - Extending the Anion Channelrhodopsin-Based Toolbox for Plant Optogenetics
JF  - Membranes
N2  - Optogenetics was developed in the field of neuroscience and is most commonly using light-sensitive rhodopsins to control the neural activities. Lately, we have expanded this technique into plant science by co-expression of a chloroplast-targeted β-carotene dioxygenase and an improved anion channelrhodopsin GtACR1 from the green alga Guillardia theta. The growth of Nicotiana tabacum pollen tube can then be manipulated by localized green light illumination. To extend the application of analogous optogenetic tools in the pollen tube system, we engineered another two ACRs, GtACR2, and ZipACR, which have different action spectra, light sensitivity and kinetic features, and characterized them in Xenopus laevis oocytes, Nicotiana benthamiana leaves and N. tabacum pollen tubes. We found that the similar molecular engineering method used to improve GtACR1 also enhanced GtACR2 and ZipACR performance in Xenopus laevis oocytes. The ZipACR1 performed in N. benthamiana mesophyll cells and N. tabacum pollen tubes with faster kinetics and reduced light sensitivity, allowing for optogenetic control of anion fluxes with better temporal resolution. The reduced light sensitivity would potentially facilitate future application in plants, grown under low ambient white light, combined with an optogenetic manipulation triggered by stronger green light.
KW  - optogenetics
KW  - rhodopsin
KW  - light-sensitive anion channel
KW  - surface potential recording
KW  - pollen tube
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236617
SN  - 2077-0375
VL  - 11
IS  - 4
ER  - 
TY  - JOUR
A1  - Huang, Shouguang
A1  - Ding, Meiqi
A1  - Roelfsema, M. Rob G.
A1  - Dreyer, Ingo
A1  - Scherzer, Sönke
A1  - Al-Rasheid, Khaled A. S
A1  - Gao, Shiqiang
A1  - Nagel, Georg
A1  - Hedrich, Rainer
A1  - Konrad, Kai R.
T1  - Optogenetic control of the guard cell membrane potential and stomatal movement by the light-gated anion channel GtACR1
JF  - Science Advances
N2  - Guard cells control the aperture of plant stomata, which are crucial for global fluxes of CO\(_2\) and water. In turn, guard cell anion channels are seen as key players for stomatal closure, but is activation of these channels sufficient to limit plant water loss? To answer this open question, we used an optogenetic approach based on the light-gated anion channelrhodopsin 1 (GtACR1). In tobacco guard cells that express GtACR1, blue- and green-light pulses elicit Cl\(^-\) and NO\(_3\)\(^-\) currents of -1 to -2 nA. The anion currents depolarize the plasma membrane by 60 to 80 mV, which causes opening of voltage-gated K+ channels and the extrusion of K+. As a result, continuous stimulation with green light leads to loss of guard cell turgor and closure of stomata at conditions that provoke stomatal opening in wild type. GtACR1 optogenetics thus provides unequivocal evidence that opening of anion channels is sufficient to close stomata.
KW  - abscisic-acid activation
KW  - Arabidopsis thaliana
KW  - H+-atpase
KW  - signal transduction
KW  - potassium channel
KW  - intact plants
KW  - K+ channels
KW  - R-type
KW  - CO2
KW  - SLAC1
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260925
VL  - 7
IS  - 28
ER  -