Changxin Liu and Jinyin Lv
College of Life Sciences, Northwest A&F University, China
The non-leaf organs of wheat performed higher tolerance than leaf in the adverse environment. To investigate the drought tolerance in wheat spike, we investigated variations of gene expression in the early filing period at 6d post anthesis (DPA) by using Affymetrix Wheat Genome Array. 30, 768 probe sets of total 61,703 ones were identified of wheat glumes at the mRNA level. 256 differentially expressed probe sets were identified. A total of 229 probe sets were up-regulated (FC≥2.0) and 27 were down-regulated(FC≤0.5) under drought stresses. Most up-regulated genes were involved in functions such as signal transduction, metabolism and transcription. Among the upregulated genes, we identified signaling proteins, transcription factors and abiotic stress-related genes. The signal pathway networks constructed with KEGG showed three important genes involved in the phenylalanine metabolism, in which phenylalanine ammonialyase, cinnamic acid hydroxylase, chalcone synthase and chalcone isomerase located at the center of the pathway, which indicated their pivotal roles in the phenylalanine metabolism and flavonoid biosynthesis derived from carbohydrate metabolism. Real-time PCR analysis confirmed that 10 genes were up-regulated and down-regulated at 0, 6, 12, 18, 24 DPA. Most up-regulated genes were involved significantly regulated by drought stresses were of unknown function; our results provide new insights into the molecular mechanism of the wheat spike responses against drought stress.
Keywords: Wheat glume, drought stress, microarray, qRT-PCR.