The 1st congress of cytotechnology & its application 11 Nov. 2008-Congress of Cytotechnology, Ferdowsi University of Mashhad Phosphoenolpyruvate Carboxykinase in Chickpea: Changes in Gene Expression during Vegetative and Reproductive Development Beihaghi Maria1, Bahrami Ahmad Reza2, Bagheri Abolreza1. 1) faculty of Agriculture, Ferdowsi university. 2) Istitute of Biotechnology Ferdowsi university of Mashhad In plants, phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.49) is a cytosolic enzyme that catalyzes the conversion of oxaloacetate (OAA) to phosophoenol pyruvate (PEP). In the process, one molecule of GTP is converted to GDP and a phosphate group is transferred to oxaloacetate. There is also the release of one molecule of carbon dioxide. For some cells and tissues, there is evidence that PEPCK plays a role in the metabolism of nitrogenous compounds In developing seeds of legumes, amides and ureides are transformed into amino acids necessary for the synthesis of storage proteins. We have been studying the tissue specific expression and possible and function(s) of PEP carboxykinase (PEPCK) in developing seeds of pea and of the model legume, Medicago truncatula, to investigate the interactions between carbon and nitrogen metabolism. Developing seeds import large amounts of nitrogenous compounds, usually as amino acids, and amides in the phloem, and a large proportion of these are used in the synthesis of seed proteins. In this study, first the total protein of seed in 21 chickpea genotypes were compared and two genotypes with highest and lowest level of protein content were chosen and designated as high and low protein respectively. PEPCK gene expression in different tissues of Chickpea (Cicer arietinume) was determined during both vegetative and reproductive growth in these selected. Total RNA was extracted from C. arietinume flowers and different developmental stages. To differentiate the expression pattern of Chickpea PEPCK gene, estimation method was RT-PCR which showed that PEPCK mRNA was present in flowering and developing growth. More precisely, the expression of PEPCK is regulated at the step where the gene for PEPCK is transcribed from DNA to RNA, thus PEPCK is said to be transcriptionally regulated mRNA appeared to be more abundant and was present in a wider range of tissues. PEPCK expression was obvious in flowers, developing seeds, and germinating seeds. More interesting this study shows that there are possibly two isofoms for the same gene of the PEPCK in chickpea. Overall the expression of the gene is higher in in the seeds with high protein rate showing a possible correlation between PEPCK and seed protein content. . P 155

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