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Exploring CO2 permeability of plant aquaporins
Author(s) -
Qin Xue,
Hu Honghong,
Schroeder Julian I,
Boron Walter F
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1103.8
Subject(s) - aquaporin , xenopus , tonicity , water transport , permeability (electromagnetism) , arabidopsis , extracellular , biophysics , chemistry , membrane permeability , microbiology and biotechnology , plant cell , osmosis , biochemistry , biology , membrane , water flow , mutant , gene , environmental engineering , engineering
Previous work showed that tobacco aquaporin can mediate CO 2 transport and has significant function in photosynthesis and in stomatal opening. However, the CO 2 permeability of aquaporins in Arabidopsis had not been fully investigated. Here we study the CO 2 permeability of aquaporins expressed in Arabidopsis . We monitored cell swelling under hypotonic conditions to compute osmotic water permeability (P f ), and used microelectrodes to monitor the maximum rise in extracellular surface pH (ΔpH S ) caused by CO 2 influx into Xenopus oocytes (an index of CO 2 permeability). When exposed to CO 2 , oocytes injected with different subclasses of plant aquaporins had different ΔpH S changes compared with day‐matched H 2 O‐injected oocytes. Under hypotonic conditions, oocytes injected with different subclasses of plant aquaporins also exhibit different water permeability. In addition, when the plant aquaporins are co‐expressed with other candidate regulators of CO 2 transport, we also observed different modulation of ΔpH S . In conclusion, these data implicate a plant aquaporin in Arabidopsis , in the transport not only of water but also of CO 2 , and raise the possibility of the regulation of CO 2 permeability. Funded by AHA 11POST7670014 & ONR N00014 ‐ 08‐10532.