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Tumour development in Arabidopsis thaliana involves the Shaker ‐like K + channels AKT1 and AKT2/3
Author(s) -
Deeken Rosalia,
Ivashikitalya,
Czirjak Tina,
Philippar Katrin,
Becker Dirk,
Ache Peter,
Hedrich Rainer
Publication year - 2003
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2003.01766.x
Subject(s) - biology , akt1 , arabidopsis thaliana , arabidopsis , potassium channel , microbiology and biotechnology , population , gene , genetics , signal transduction , pi3k/akt/mtor pathway , biophysics , demography , sociology , mutant
Summary After completion of the Arabidopsis genome‐sequencing programme, crown galls induced by Agrobacterium tumefaciens may become a model system to study plant tumour development. The molecular mechanisms of nutrient supply to support tumour growth and development are still unknown. In this study, we have identified a unique profile of Shaker ‐like potassium channels in agrobacteria‐induced Arabidopsis tumours. Comparing the gene expression pattern of rapidly growing tumours with that of non‐infected tissues, we found the suppression of shoot in favour of root‐specific K + channels. Among these, the upregulation of AKT1 and AtKC1 and the suppression of AKT2/3 and GORK were most pronounced. As a consequence, K + uptake and accumulation were elevated in the tumour (163 m m ) compared to control tissues (92 m m ). Patch clamp studies on tumour protoplasts identified a population expressing the electrical properties of the AKT1 K + channel. Furthermore, plants lacking a functional AKT1 or the AKT2/3 phloem K + channel gene did not support tumour growth. This indicates that the delivery of potassium by AKT1 and the direction of assimilates, triggered by AKT2/3, are essential for tumour growth.