DifferentialGeneExpression in Response to DroughtStress in MaizeSeedling

Journal: Agricultural Sciences in China. 2009,8: 767-776

Author: DENG Xiao-feng, FU Feng-ling, NI Na and LI Wan-chen

Abstract:

To provide the useful information for the choice of molecular marker used in marker-assisted selection of drought tolerance, it is necessary to find out more candidate genes and fulfill the information gaps in geneexpression regulation under droughtstress. In this study, we isolated four differentially expressed cDNA fragments from leaves of a drought-tolerant inbred line by suppression subtractive hybridization and reverse Northern hybridization, and validated their differentialexpression patterns among six inbred lines with different drought tolerance in response to droughtstress by quantitative real-time PCR. Sequence similarity analysis indicated that two of four differentially expressed cDNA showed homology to geneDegP encoding trypsin-like serine protease, and genePGAM-i encoding cofactor-independent phosphoglyceromutase, respectively. Expressions of the genes corresponding to four cDNA fragments was decreased at 6 h after droughtstress treatment in most of the six inbred lines, and then returned to the control level with further stress in three of the tolerant inbred lines. The expression of the genePGAM-i and the genes corresponding to fragments E4 and F4 were increased to a high level in tolerant inbred line 81565. In the two drought-sensitive inbred lines (Dan340 and ES40), the expression of these genes was still down-regulated. The probable mechanisms of these genes in response to droughtstress were discussed. These results indicated that the drought-tolerant inbred lines up-regulated the expression of the drought-tolerant candidate genes, in contrast, drought-sensitive inbred lines down-regulated the expression of the genes.

Link: http://www.sciencedirect.com/science/article/pii/S1671292708602771