Journal
PROTEOMICS
Volume 8, Issue 20, Pages 4317-4326Publisher
WILEY
DOI: 10.1002/pmic.200800292
Keywords
Arabidopsis; Peptide mass fingerprinting; Phosphate starvation; Secreted protein
Funding
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Queen's Research Chairs program
Ask authors/readers for more resources
A proteomic approach was applied to compare the secretome (culture filtrate proteome) of phosphate-sufficient (+Pi) and Pi-deficient (-Pi) Arabidopsis thaliana suspension cell cultures. Secretomes harvested from the +Pi and -Pi cells yielded dissimilar 2-DE maps. PMF via MALDI-TOF MS resulted in the identification of 50 protein spots representing 37 discrete proteins having unique gene identities. A total of 24 Pi-starvation responsive proteins were identified, with 18 of these being up-regulated and six down-regulated. Secreted proteins up-regulated by the -Pi cells included a ribonuclease involved in Pi scavenging from extracellular nucleic acids, as well as enzymes of cell wall modification, proteolysis, pathogen responses, and ROS metabolism. Enzyme activity assays and immunoblotting demonstrated that a pair of purple acid phosphatase isoforms having subunit M(r)s of 65 and 55 kDa was also secreted by the -Pi cells. Semiquantitative RT-PCR was used to assess the relationship between mRNA levels and relative amounts of selected secretome proteins. The results indicate that transcriptional control is but one of many factors contributing to Arabidopsis Pi starvation responses, and highlight the importance of parallel biochemical/proteomic studies of -Pi plants.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available