caa a22 4500 477101526 CHVBK 20180405111543.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF00195725 doi (NATIONALLICENCE)springer-10.1007/BF00195725 The role of calmodulin in the gravitropic response of the Arabidopsis thaliana agr -3 mutant [Elektronische Daten] [William Sinclair, Ian Oliver, Paddy Maher, Anthony Trewavas] Calmodulin, a primary plant calcium receptor, is known to be intimately involved with gravitropic sensing and transduction. Using the calmodulin-binding inhibitors trifluoperazine, W7 and calmidazolium, gravitropic curvature of Arabidopsis thaliana (L.) Heynh, ecotype Landsberg, roots was separable into two phases. Phase I was detected at very low concentrations (0.01 μM) of trifluoperazine and calmidazolium, did not involve growth changes, accounted for about half the total curvature of the root and may represent the specific contribution of the cap to gravity sensing. Phase II commenced around 1.0 μM and involved inhibition of both growth and curvature. The agr-3 mutant exhibited a reduced gravitropic response and was found to lack phase I curvature, suggesting that the mutation alters either use or expression of calmodulin. The sequences of wild-type and agr-3 calmodulin (CaM-1) cDNAs, which are root specific were completely determined and found to be identical. Upon gravitropic stimulation, wild-type Arabidopsis seedlings increased calmodulin mRNA levels by threefold in 0.5 h. On the other hand, gravitropic stimulation of agr-3 decreased calmodulin mRNA accumulation. The possible basis of the two phases of curvature is discussed and it is concluded that agr-3 has a lesion located in a general gravity transmission sequence, present in many root cells, which involves calmodulin mRNA accumulation. Springer-Verlag, 1996 Arabidopsis nationallicence Calmodulin nationallicence Gravitropism nationallicence CaM : calmodulin nationallicence TFP : trifluoperazine nationallicence W5 : N-(6-aminohexyl)-1-naphthalenesulfonamide nationallicence W7 : N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide nationallicence Sinclair William Institute of Ecology and Resource Management, University of Edinburgh, Mayfield Road, EH9 3JU, Edinburgh, UK aut Oliver Ian Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, EH9 3JU, Edinburgh, UK aut Maher Paddy The Open University in Scotland, 10 Drumsheugh Gardens, EH3 7QJ, Edinburgh, UK aut Trewavas Anthony Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, EH9 3JU, Edinburgh, UK aut Planta Springer-Verlag 199/3(1996-07-01), 343-351 0032-0935 199:3<343 1996 199 425 https://doi.org/10.1007/BF00195725 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00195725 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sinclair William Institute of Ecology and Resource Management, University of Edinburgh, Mayfield Road, EH9 3JU, Edinburgh, UK aut NATIONALLICENCE 700 1- Oliver Ian Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, EH9 3JU, Edinburgh, UK aut NATIONALLICENCE 700 1- Maher Paddy The Open University in Scotland, 10 Drumsheugh Gardens, EH3 7QJ, Edinburgh, UK aut NATIONALLICENCE 700 1- Trewavas Anthony Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, EH9 3JU, Edinburgh, UK aut NATIONALLICENCE 773 0- Planta Springer-Verlag 199/3(1996-07-01), 343-351 0032-0935 199:3<343 1996 199 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer