Postdoc in Plant Molecular Biology
Institute of Biochemistry and Biophysics, Polish Academy of Sciences
Institute of Biochemistry and Biophysics Polish Academy of Science in Warsaw, Biochemistry Department announces a call for candidates for the post-doc position for the implementation of the Opus project receiving the financial aid from polish National Science Centre “Search for molecular mechanism, of annexin-mediated chloroplast protection against high light stress in Arabidopsis thaliana”.
The main purpose of the project is to study annexin-dependent mechanism of the chloroplast protection against the consequences of oxidative stress and its possible role in ROS cross-talk between different compartments. The common consequence of various environmental and biotic stresses is imbalance between the synthesis and scavenging of free oxygen radicals, collectively called reactive oxygen species (ROS). Transient ROS accumulation forming a metabolic interface between stress perception and physiological responses which is still poorly. ROS play an important role in the activation of endogenous developmental programs and in adaption to a constantly changing environment. Recent data show that specificity of acting stimulus is encoded in the ROS profile and cellular responses mediated by various forms of ROS are specific, suggesting that certain types of ROS activate distinct signaling pathways. This allows the best tailoring of the cellular response to the current challenge. A stress-induced transient ROS accumulation begins within the chloroplast, where due to external restrictions light energy is no longer used efficiently for photosynthesis and then the secondary sources of ROS in other cellular compartments are mobilized. Production of ROS in the cytoplasm, apoplast, in return activates their generation in the chloroplast and both can regulate nuclear gene expression. The mechanisms of ROS signaling and communication between the organelle are still barely grasp.
In the previous studies we have shown that certain annexin from Arabidopsis thaliana and other plant species have the ability to stabilize the redox poise in eukaryotic cells. Over-expression of these two proteins conferred drought tolerance and allowed them to maintain the efficient photosynthesis during the stress. It was, at least partially, due to improved ability to harmlessly dissipate the excess of absorbed energy in the process of non-photochemical quenching (NPQ). Additionally, the mRNA level of nuclear genes regulated by retrograde chloroplast-to-nucleus signaling was altered. However, the molecular mechanisms of this process remain unclear. We assume that annexin can interfere with ROS-mediated signaling acting possible as a cytosolic scavenger. In Arabidopsis the cross-talk between ROS neutralizing systems from different compartments were reported. The chloroplast scavenging enzymes are rapidly inhibited by ROS accumulation and deletion of cytosolic but not chloroplast scavenging capacity resulted in collapse of the chloroplast.
To achieve our goals we are going to employ the two types of Arabidopsis thaliana conditional mutants over-accumulating different types of ROS in the chloroplast in a light-inducible manner. GO line was generated by re-directing of photorespiratory rescue pathway to the chloroplast; they offer a tool to functionally dissect the action of plastid-generated H2O2. In turn, flu plants can be used to determine the biological activity of singlet oxygen that is produced in the chloroplast during a dark-to-light transition. It was shown that the sets of nuclear gene induced by accumulation of hydrogen peroxide and singlet oxygen varies. We will examine the impact of elevated levels of annexin on nuclear genes expression, the accumulation of ROS and scavenging system functioning, especially accumulation of low molecular weight antioxidants (carotenoids, glutathione, ascorbate) in both mutant lines. This approach will enable us to investigate an in vivo cross-talk between cytosol- and chloroplast-derived oxidative signaling. The profile of accumulated ROS, effectiveness of annexin’s activity toward scavenging of specific ROS will be also examine.
The scope of tasks of post-doc in the project:
- the growth of selected Arabidopsis mutant lines;
- plant experiments;
- the preparation of the plant test material for deep RNA sequencing;
- the qualitative and quantitative analysis of the acquired data;
- the confirmation of the obtained results with quantitative PCR;
- the preparation of manuscripts;
- previous experience in RNA, especially qPCR (primer design, result processing) will be a plus.
Principle Investigator: dr Dorota Konopka-Postupolska
Project duration: 28 months
Number of positions: 1 (full-time employment contract)
Getting started: after the recruitment process
Remuneration: 5 000,00 PLN per month (gross)
Candidates are requested to send the following documents:
- a copy of doctoral diploma (or the faculty council's resolution on title assignment);
- scientific cv (with agreement “I hereby agree for processing the following personal”);
- information for the purpose of recruitment, in accordance with the Personal Data Protection Act dated 29/08/1997 (No.102, item 926 and successive amendments);
- letter of motivation with the description of the previous work;
- letter of reference from the doctoral dissertation promoter or project PI;
- list of publications/patents/conference presentations.
Applications should be sent by e-mail to email@example.com by 31.05.2017.
Evaluation will be two-stage:
1. The first stage - the Selection Committee (2 independent researchers from IBB PAS and the PI) will evaluate the documents. Based on this analysis will be selected people who will go to the second stage.
We reserve the right to contact only selected candidates.
2. Second stage - qualification interviews with the Selection Committee, short presentation of the research project - 19.06.2017.
It is desirable to start work within one month after submitting the recruitment results.
3. Based on the results of the second stage, the project contractor will be selected.
All candidates invited to speak will be notified of the results of the recruitment procedure.