Ion flux kinetics in blue light‐grown field dodder (Cuscuta campestris) seedlings |
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| Authors: | Mustapha Haidar Sergey Shabala |
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| Affiliation: | 1. Department of Agricultural Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon;2. School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia |
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| Abstract: | Previous studies have revealed that blue light stimulates coiling and prehaustoria development in young de‐etiolated dodder seedlings prior to host attachment. In this study, the Ca2+ and H+ flux kinetics that are associated with blue light‐mediated coiling and prehaustoria development in de‐etiolated dodder seedlings were measured uninvasively using the ion‐selective, vibrating microelectrode ion flux system. The findings showed that blue light induces rapid transient changes in the net Ca2+ and H+ fluxes. A clearly pronounced lag of about several minutes was observed between the blue light‐induced changes in the Ca2+ and H+ fluxes, with H+ being a leading ion. The addition of 1 mol L?1 vanadate, a known blocker of the plasma‐membrane H+‐ATPase, to the bathing solution completely prevented both the H+ and the Ca2+ flux responses and inhibited coiling and prehaustoria development, suggesting a causal relationship between the blue light‐induced changes in the net Ca2+ and H+ fluxes and seedling movements. It is concluded that the plasma‐membrane H+‐ATPase plays a key role in a dodder's parasitic mode of growth and its adaptive response to the environment. |
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| Keywords: | blue light dodder H+‐ATPase ion fluxes |
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