TY - JOUR
T1 - The effects of the loss of TIP1;1 and TIP1;2 aquaporins in Arabidopsis thaliana
AU - Schüssler, Manuela Désirée
AU - Alexandersson, Erik
AU - Bienert, Gerd Patrick
AU - Kichey, Thomas
AU - Laursen, Kristian Holst
AU - Johanson, Urban
AU - Kjellbom, Per
AU - Schjoerring, Jan Kofod
AU - Jahn, Thomas Paul
PY - 2008/12
Y1 - 2008/12
N2 - Loss of aquaporin TIP1;1 in Arabidopsis has been suggested to result in early senescence and plant death. This was based on the fact that a partial reduction of TIP1;1 by RNA interference (RNAi) led to gradual phenotypes, ranging from indistinguishable from wild type to lethality, depending on the degree of downregulation of the target messenger, and displaying pleiotropic effects in primary metabolism and cell signalling. A hypothesis was put forward to suggest that TIP1;1, apart from its transport function, may play an essential role in vesicle routing. Here we identify an Arabidopsis transposon insertion line tip1;1-1 that is completely devoid of TIP1;1 protein, as demonstrated by western blotting and immunolocalization using an isoform-specific antibody. Strikingly, the complete absence of the protein did not result in any significant effect on metabolism or elemental composition of the plants. Microarray analysis did not indicate increased expression of other aquaporins to compensate for the lack of TIP1;1 in tip1;1-1. We further developed a double mutant of TIPs in Arabidopsis, lacking both TIP1;1 and its closest paralog TIP1;2. Arabidopsis mutants lacking both TIP1;1 and TIP1;2 showed a minor increase in anthocyanin content, and a reduction in catalase activity, but showed no changes in water status. In contrast to earlier reports, plants lacking TIP1;1 and TIP1;2 aquaporins are alive and thriving. We suggest that RNAi directed towards TIP1;1 may have resulted in off-target gene silencing, a notion that is potentially interesting for various studies analysing gene function by RNAi.
AB - Loss of aquaporin TIP1;1 in Arabidopsis has been suggested to result in early senescence and plant death. This was based on the fact that a partial reduction of TIP1;1 by RNA interference (RNAi) led to gradual phenotypes, ranging from indistinguishable from wild type to lethality, depending on the degree of downregulation of the target messenger, and displaying pleiotropic effects in primary metabolism and cell signalling. A hypothesis was put forward to suggest that TIP1;1, apart from its transport function, may play an essential role in vesicle routing. Here we identify an Arabidopsis transposon insertion line tip1;1-1 that is completely devoid of TIP1;1 protein, as demonstrated by western blotting and immunolocalization using an isoform-specific antibody. Strikingly, the complete absence of the protein did not result in any significant effect on metabolism or elemental composition of the plants. Microarray analysis did not indicate increased expression of other aquaporins to compensate for the lack of TIP1;1 in tip1;1-1. We further developed a double mutant of TIPs in Arabidopsis, lacking both TIP1;1 and its closest paralog TIP1;2. Arabidopsis mutants lacking both TIP1;1 and TIP1;2 showed a minor increase in anthocyanin content, and a reduction in catalase activity, but showed no changes in water status. In contrast to earlier reports, plants lacking TIP1;1 and TIP1;2 aquaporins are alive and thriving. We suggest that RNAi directed towards TIP1;1 may have resulted in off-target gene silencing, a notion that is potentially interesting for various studies analysing gene function by RNAi.
KW - Aquaporin
KW - Insertion line
KW - Off-targeting
KW - RNAi
KW - TIP1
UR - http://www.scopus.com/inward/record.url?scp=57449084176&partnerID=8YFLogxK
U2 - 10.1111/j.1365-313X.2008.03632.x
DO - 10.1111/j.1365-313X.2008.03632.x
M3 - Article
C2 - 18643996
AN - SCOPUS:57449084176
SN - 0960-7412
VL - 56
SP - 756
EP - 767
JO - Plant Journal
JF - Plant Journal
IS - 5
ER -