New signalling network in plant abiotic stress discovered through a genetic approach

A new collection of Arabidopsis mutants deregulated in the response to abiotic stresses has been isolated using an EMS-mutagenised population carrying the luciferase cDNA under the control of the RCI2A promoter. RCI2A gene is expressed after exposure to low temperatures, dehydration, high salinity, and the ectopic application of the phyto-hormone abscisic acid. <br>Two characterised recessive mutants (lor19 and lor42) exhibiting a lower expression of RCI2A after the stress treatments, in comparison to the wild type, have been proven to be also affected in their tolerance to some of these adverse conditions. Moreover, two dominant mutants (hor29 and hor106) presenting an enhanced expression of the RCI2A gene have also been shown to be altered in the sensitivity to the different stress factors. <br>The results presented, also confirmed the interactive relationships between different signalling pathways triggered by the stress factors tested, indicating new features on the control of the expression of RCI2A. First, a novel cold-signalling pathway different to the CBF/DREB1-dependent pathway, was proposed to induce the expression of the RCI2A. Second, a differential regulation of the transgene in shoot and root organs, has been observed in one of the studied mutants, after salt and ABA treatments. And third, an enhanced expression of the RCI2A::luc transgene in root tissues after ethylene treatment, indicates the involvement of the phytohormone in the induction of RCI2A in this organ. <br>The four mutations (lor19, lor42, hor29, and hor106) characterised have been linked to different chromosomal regions, and the positions obtained indicate that the isolated mutants do not correspond to already described mutations affecting the regulation of the different stress signalling pathways. Further mapping of the mutations will lead to the positional cloning of the affected genes, identifying new elements involved in the Arabidopsis abiotic stress signalling cascades.

Author dc:creator

• Peñalosa-Barbero, Andrés

Contributors dc:contributor

• Neuhaus, Gunther

• abiotischer Stress
• Luziferase
• RCI2A
• Pflanzen
• abiotic stress
• luciferase
• plants

Repository record source_url

https://freidok.uni-freiburg.de/data/1358

OAI identifier oai:identifier

oai:freidok.uni-freiburg.de:1358