The cyclic nucleotide-gated channel, AtCNGC10, influences salt tolerance in Arabidopsis.
Cyclic nucleotide-gated channels (CNGCs) in the plasma membrane transport K+ and other cations; however, their roles in the response and adaptation of plants to environmental salinity are unclear. Growth, cation contents, salt tolerance and K+ fluxes were assessed in wild-type and two AtCNGC10 antisense lines (A2 and A3) of Arabidopsis thaliana (L.) Heynh. Compared with the wild-type, mature plants of both antisense lines had altered K+ and Na+ concentrations in shoots and were more sensitive to salt stress, as assessed by biomass and Chl fluorescence. The shoots of A2 and A3 plants contained higher Na+ concentrations and significantly higher Na+/K+ ratios compared with wild-type, whereas roots contained higher K+ concentrations and lower Na+/K+ ratios. Four-day-old seedlings of both antisense lines exposed to salt stress had smaller Na+/K+ ratios and longer roots than the wild-type. Under sudden salt treatment, the Na+ efflux was higher and the K+ efflux was smaller in the antisense lines, indicating that AtCNGC10 might function as a channel providing Na+ influx and K+ efflux at the root/soil interface. We conclude that the AtCNGC10 channel is involved in Na+ and K+ transport during cation uptake in roots and in long-distance transport, such as phloem loading and/or xylem retrieval. Mature A2 and A3 plants became more salt sensitive than wild-type plants because of impaired photosynthesis induced by a higher Na+ concentration in the leaves.
Guo
Kun-Mei
KM
School of Earth and Geographical Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia.
Babourina
Olga
O
Christopher
David A
DA
Borsics
Tamas
T
Rengel
Zed
Z
D000222:Adaptation, Physiological / Q000187:drug effects*; D017360:Arabidopsis / Q000187:drug effects* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018533:Biomass; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000378:metabolism*; D017136:Ion Transport / Q000187:drug effects; D018519:Meristem / Q000187:drug effects / Q000254:growth & development; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*
D029681:Arabidopsis Proteins; C525437:CNGC10 protein, Arabidopsis; D054815:Cyclic Nucleotide-Gated Cation Channels; D012965:Sodium Chloride