Franka Siefritz

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Aquaporins, found in virtually all living organisms, are membrane-intrinsic proteins that form water-permeable complexes. The mammalian aquaporin AQP1 has also shown CO2 permeability when expressed heterologously in Xenopus oocytes, although whether this is a biochemical curiosity or of physiological significance is a matter of debate. Here we report that,(More)
The molecular functions of several aquaporins are well characterized (e.g., by analysis of aquaporin-expressing Xenopus oocytes). However, their significance in the physiology of water transport in multicellular organisms remains uncertain. The tobacco plasma membrane aquaporin NtAQP1 was used to elucidate this issue. By comparing antisense plants that were(More)
Epinastic leaf movement of tobacco is based on differential growth of the upper and lower leaf surface and is distinct from the motor organ-driven mechanism of nyctinastic leaf movement of, for example, mimosa species. The epinastic leaf movement of tobacco is observed not only under diurnal light regimes but also in continuous light, indicating a control(More)
This paper gives a summary of a project to characterize a tobacco aquaporin. The cDNA and gene, including the 5' upstream region, for the tobacco aquaporin NtAQP1 has been isolated and the encoded protein characterized. The significance of promoter regions for an abscisic acid- and gibberellic acid-induced gene expression could be restricted to a region(More)
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