Expression profiling of the genes induced by Na2CO3 and NaCl stresses in leaves and roots of Leymus chinensis

Alkaline soil is more challenging factor to grow plants than saline soil based on the size of its affected area. To reveal genetic expression changes by alkaline and saline soil, Leymus chinensis (Trin.) Tzvel. was examined response to Na2CO3 and NaCl stresses by using microarray chips comprising 1642 cDNA clones, previously reported by us. A total of 536 genes were responsive to Na2CO3 and NaCl stresses by upregulation or down-regulation. We observed transcriptional changes arose more to Na2CO3 stress, or leaves than to NaCl stress or roots, respectively, in L. chinensis genome. Overall, 99 and 59 genes were upregulated, while 365 and 176 genes were down-regulated in leaves and roots, respectively; demonstrating down-regulation occurs more as the response to the Na2CO3 and NaCl stress. The majority of the down-regulated genes (30.1%) were classified to photosynthesis related proteins while that of the up-regulated genes were categorized into metabolism proteins or noble proteins. Only 37 genes in the stressed leaves and 6 genes in the stressed roots were showed the same expression changing patterns between Na2CO3 and NaCl stresses during three time points of detections. Among those genes, 70% were constantly up-regulated or down-regulated during our detection presenting difference in the gene regulation systems against two difference stress, the saline-alkali stress (Na2CO3) and saline stress (NaCl). In addition, a total of 87 genes detected in this study were characterized to the unclassified proteins, whereas 72 had no similarity to the current GenBank databases which were considered as novel proteins detected in the alkali and saline stressed L. chinensis genome. The four important genes to abiotic stress tolerance, ACC, GDP, hsp70, and elF1 were detected constantly for all of three time points of stressed which are the grand candidates for establishing stress tolerance plants by developing transgenic. (c) 2008 Elsevier Ireland Ltd. All rights reserved.