|Kottapalli, Kameswara Rao|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/22/2007
Publication Date: 9/26/2007
Citation: Payton, P.R., Kottapalli, K., Burow, M., Burke, J.J., Tissue, D., Faircloth, W.H., Rowland, D., Gallo, M., Puppala, N. 2007. Physiological genomics of abiotic stress responses in peanut[abstract]. ComBio 2007 - Annual Meeting of the Australian Society for Biochemistry and Molecular Biology. Sydney, Australia. Spetember 22-26, 2007. Interpretive Summary:
Technical Abstract: Peanut (Arachis hypogaea L.) accessions from the U.S. mini-core collection were independently evaluated for heat and water-deficit stress tolerance using a battery of physiological assays including leaf-level gas exchange, chlorophyll fluorescence yield, membrane thermostability, leaf sugar content, biomass accumulation, specific leaf area, and water use efficiency. Subsequently, accessions showing tolerant and susceptible responses to stress were selected for transcript and protein profiling studies. We have developed an oligonucleotide microarray from publically available peanut and legume ESTs that represents 15,000 unique genes. Transcript profiling of leaf, root, and pod tissues indicates several novel pathways correlated with heat and water-deficit stress tolerance in selected lines. 1-D gel immunoblotting revealed a significant decrease in the oxidative-stress related ascorbate peroxidase (APX) in the tolerant accession and low molecular weight heat shock protein (HSP 30) in the susceptible accession under stress. A total of 40 and 79 protein bands/spots from 1D and 2 D gels, respectively, were excised for analysis by using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and by MS/MS analysis, and 35 non-redundant proteins were identified. The photosynthetic enzymes, ribulose 1,5-biphosphate carboxylase-oxygenase and carbonic anhydrase were induced under stress, suggesting possible photosynthetic adaptation in tolerant accessions. Lipoxygenase involved in jasmonic acid synthesis was suppressed, while a signaling protein, oxygen evolving enhancer 2(OEE2) was induced under water stress. Interestingly, acetyl-CoA carboxylase carboxyl transferase, an enzyme of fatty acid biosynthesis, was induced only in the tolerant accession, indicating its putative role in the tolerance response. The identified proteins from peanut leaves and their corresponding genes can be incorporated in marker assisted breeding for drought tolerance in peanut. Details of this study, including transcript profiling and transformation of peanut with selected genes will be reported at this meeting.