%0 Journal Article %1 Philippar12101999 %A Philippar, Katrin %A Fuchs, Ines %A Lüthen, Hartwig %A Hoth, Stefan %A Bauer, Claudia S. %A Haga, Ken %A Thiel, Gerhard %A Ljung, Karin %A Sandberg, Göran %A Böttger, Michael %A Becker, Dirk %A Hedrich, Rainer %D 1999 %J Proceedings of the National Academy of Sciences %K myown %N 21 %P 12186-12191 %R 10.1073/pnas.96.21.12186 %T Auxin-induced K+ channel expression represents an essential step in coleoptile growth and gravitropism %U http://www.pnas.org/content/96/21/12186.abstract %V 96 %X Auxin-induced growth of coleoptiles depends on the presence of potassium and is suppressed by K+ channel blockers. To evaluate the role of K+ channels in auxin-mediated growth, we isolated and functionally expressed ZMK1 and ZMK2 (Zea mays K+ channel 1 and 2), two potassium channels from maize coleoptiles. In growth experiments, the time course of auxin-induced expression of ZMK1 coincided with the kinetics of coleoptile elongation. Upon gravistimulation of maize seedlings, ZMK1 expression followed the gravitropic-induced auxin redistribution. K+ channel expression increased even before a bending of the coleoptile was observed. The transcript level of ZMK2, expressed in vascular tissue, was not affected by auxin. In patch-clamp studies on coleoptile protoplasts, auxin increased K+ channel density while leaving channel properties unaffected. Thus, we conclude that coleoptile growth depends on the transcriptional up-regulation of ZMK1, an inwardly rectifying K+ channel expressed in the nonvascular tissue of this organ.

@article{Philippar12101999, abstract = {Auxin-induced growth of coleoptiles depends on the presence of potassium and is suppressed by K+ channel blockers. To evaluate the role of K+ channels in auxin-mediated growth, we isolated and functionally expressed ZMK1 and ZMK2 (Zea mays K+ channel 1 and 2), two potassium channels from maize coleoptiles. In growth experiments, the time course of auxin-induced expression of ZMK1 coincided with the kinetics of coleoptile elongation. Upon gravistimulation of maize seedlings, ZMK1 expression followed the gravitropic-induced auxin redistribution. K+ channel expression increased even before a bending of the coleoptile was observed. The transcript level of ZMK2, expressed in vascular tissue, was not affected by auxin. In patch-clamp studies on coleoptile protoplasts, auxin increased K+ channel density while leaving channel properties unaffected. Thus, we conclude that coleoptile growth depends on the transcriptional up-regulation of ZMK1, an inwardly rectifying K+ channel expressed in the nonvascular tissue of this organ.}, added-at = {2017-03-22T11:45:37.000+0100}, author = {Philippar, Katrin and Fuchs, Ines and Lüthen, Hartwig and Hoth, Stefan and Bauer, Claudia S. and Haga, Ken and Thiel, Gerhard and Ljung, Karin and Sandberg, Göran and Böttger, Michael and Becker, Dirk and Hedrich, Rainer}, biburl = {https://www.bibsonomy.org/bibtex/2f96d8207965d87627379903c65697f5b/dirkbecker}, description = {Auxin-induced K+ channel expression represents an essential step in coleoptile growth and gravitropism}, doi = {10.1073/pnas.96.21.12186}, eprint = {http://www.pnas.org/content/96/21/12186.full.pdf}, interhash = {d9485f056cd6193a690d35737b6317fd}, intrahash = {f96d8207965d87627379903c65697f5b}, journal = {Proceedings of the National Academy of Sciences}, keywords = {myown}, number = 21, pages = {12186-12191}, timestamp = {2017-03-22T11:45:37.000+0100}, title = {Auxin-induced K+ channel expression represents an essential step in coleoptile growth and gravitropism}, url = {http://www.pnas.org/content/96/21/12186.abstract}, volume = 96, year = 1999 }