Plant Molecular Biology 17: 1077-1079, 1991. © 1991 Kluwer Academic Publishers. Printed in Belgium. Update section Sequence 1077 Complete nucleotide sequence of one member of the Sorghum phosphoenolpyruvate carboxylase gene family Lo'fc Lepiniec, Simonetta Santi, Eliane Keryer, Valrrie Amiet, Jean Vidal, Pierre Gadal and Claude Crrtin Physiologie V~g~taleMol~culaire, Bat. 430 URA CNRS Dl128, Universit~ Paris Sud, 91405 Orsay Cedex, France Received 26 June 1991; accepted 1 July 1991 Key words: phosphoenolpyruvate carboxylase gene, C4 plant, Sorghum, C3-type gene Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) is an ubiquitous enzyme in plants and in prokaryotes [8, 5]. This enzyme is mainly known for its role in the primary photosynthetic CO2 fixation in C4 and CAM plants. But many func- tions have been proposed for PEPC present in C3 plants [6]. In Sorghum (C4 plant), the enzyme is encoded in the nucleus by a small multigene fam- ily exhibiting a differential expression in leaves and in roots [2]. Two members (CP21 and 46) of the Sorghum PEPC gene family have been previ- ously characterized [ 1, 2]. Here we report the characterization of a third member (CP 28) of the PEPC gene family. Its complete nucleotide sequence has been deter- mined by the dideoxynucleotide chain termina- tion technique [ 7 ]. It consists of 6018 nucleotides, possesses 9 introns and encodes a polypeptide of 960 amino acids (Fig. 1). Comparison with full-length Sorghum cDNA [1, 2] and other genomic clones from corn [4, 9] and CAM plants [3] reveals that the CP28 gene encodes for a second C3-type PEPC. An 80-85 ~o amino acid sequences homology is seen between CP28 and members of the C3/CAM group, whereas only 70~o is obtained when compared with C4 group members. The nucleotidic sequence of the 5'-flanking DNA (600 bp) has been determined. Analyses are under way in order to identify in the three promoters, DNA elements involved in the spec- ificity of the expression of PEPC genes. References 1. Cr&in C, KeD'er E, Tagu D, Lepiniec L, Vidal J, Gadal P: Complete cDNA sequence of Sorghum phosphoenol- pyruvate carboxylase involved in C4 photosynthesis. Nucl Acids Res 18:658 (1990). 2. Crrtin C, Santi S, Keryer E, Lepiniec L, Tagu D, Vidal J, Gadal P: The phosphoenolpyruvate carboxylase gene family in sorghum: promoter structure, amino acid se- quences and expression of genes. Gene 99:87-94 (1991)). 3. Cushman JC, Meyer G, Michalowski CB, Schmitt JM, Bohnert HJ: Salt stress leads to differential expression of two isogenes of phosphoenolpyruvate carboxylase during The nucleotide sequence data reported will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession number X59925.