Cloning Of Ribosomal L5Gene And Its Expression Patterns On The Grain Filling Stage And Under Stresses In Common Whear(Triticum Aestivum L.)

In the previous studies of our lab, wheat seedlings (wheat cultivar“Yumai34”) were suffered from5°C freeze stress for3d. RNA of wheat leavesassayed at two time points (1day and3day) after5℃freeze stress was extracted forthe Affymetrix Wheat GeneChip microarray. After1and3days of freeze stress,600genes that were previously annotated as showing changes in expression of at least thantwo-fold were measured at one or both of the time points. However, the transcriptlevels of more EST sequences were changed under freeze stress condition. In thepresent study, one EST, whose transcript level increased1and3days after freezestress and whose amino acid sequence had moderate similarity to AtL5, was chosen toisolate its full cDNA length using RACE method.The results indicated that the amplified full-length cDNA sequence was1158bp,designated as TaL5. It contained the open reading frame (ORF) of906bp (the regionfrom77to982nucleotides), flanked by5′-and3′-untranslated regions of76bp and176bp, respectively. The deduced amino acid sequence (301residues) shared highsimilarity to those of other higher plant L5proteins. TaL5DNA sequence was furthercloned, and sequence analysis showed that it contained7introns and8exons.Predicated using TargetP software, TaL5protein was putatively located inmitochondria and contain a transit peptide of12amino acids. During grain fillingperiod, temporal expression pattern of TaL5gene was approximately consistent withthe rates of starch accumulation in grains. Additionally, TaL5gene was dramaticallyinduced by salt, drought and freezing stresses, exogenous abscisic acid (ABA) andsalicylic acid (SA) in wheat seedlings. These implied that TaL5gene could function ingrowth, development and abiotic stresses in wheat plants.