Abscisic acid and 14-3-3 proteins control K+ channel activity in barley embryonic root
| العنوان: | Abscisic acid and 14-3-3 proteins control K+ channel activity in barley embryonic root |
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| المؤلفون: | Ilja Roobeek, Mark P. Sinnige, Albertus H. de Boer, Annet Reumer, Mei Wang, Peter J. Schoonheim, Jos Mol, Paul W.J. van den Wijngaard |
| المصدر: | The Plant Journal. 41:43-55 |
| بيانات النشر: | Wiley, 2004. |
| سنة النشر: | 2004 |
| مصطلحات موضوعية: | Cell Biology, Plant Science, Biology, chemistry.chemical_compound, Biochemistry, chemistry, Germination, Fusicoccin, Genetics, Radicle, Biophysics, Hordeum vulgare, Patch clamp, Abscisic acid, Ion transporter, Ion channel |
| الوصف: | Germination of seeds proceeds in general in two phases, an initial imbibition phase and a subsequent growth phase. In grasses like barley, the latter phase is evident as the emergence of the embryonic root (radicle). The hormone abscisic acid (ABA) inhibits germination because it prevents the embryo from entering and completing the growth phase. Genetic and physiological studies have identified many steps in the ABA signal transduction cascade, but how it prevents radicle elongation is still not clear. For elongation growth to proceed, uptake of osmotically active substances (mainly K(+)) is essential. Therefore, we have addressed the question of how the activity of K(+) permeable ion channels in the plasma membrane of radicle cells is regulated under conditions of slow (+ABA) and rapid germination (+fusicoccin). We found that ABA arrests radicle growth, inhibits net K(+) uptake and reduces the activity of K(+) (in) channels as measured with the patch-clamp technique. In contrast, fusicoccin (FC), a well-known stimulator of germination, stimulates radicle growth, net K(+) uptake and reduces the activity of K(+) (out) channels. Both types of channels are under the control of 14-3-3 proteins, known as integral components of signal transduction pathways and instrumental in FC action. Intriguingly, 14-3-3 affected both channels in an opposite fashion: whereas K(+) (in) channel activity was fully dependent upon 14-3-3 proteins, K(+) (out) channel activity was reduced by 14-3-3 proteins by 60%. Together with previous data showing that 14-3-3 proteins control the activity of the plasma membrane H(+)-ATPase, this makes 14-3-3 a prime candidate for molecular master regulator of the cellular osmo-pump. Regulation of the osmo-pump activity by ABA and FC is an important mechanism in controlling the growth of the embryonic root during seed germination. |
| تدمد: | 1365-313X 0960-7412 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::d005a7c52e5f133bc34f66f84d03ac58 https://doi.org/10.1111/j.1365-313x.2004.02273.x |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi...........d005a7c52e5f133bc34f66f84d03ac58 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 1365313X 09607412 |
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