Gene Expression Profiling And Related Gene Cloning Of Broomcorn Millet (Panicum Miliaceum L.) During Rehydration After Drought

The shortage of water resource is a focus of attention all over the world. The influence of drought on crop production is more and more serious. Therefore, breeding the varieties with drought resistance is a good solution. After tens of year's selection, the drought resistance gene resources among main crops are very limited. So utilizing the plant resources that have the character of higher efficiency of water usage is a good choice to improve present crops. Plant often suffers from change between drought and wetting during its life cycle. Analysis of genes involved in the recovery from drought stress, as well as drought-inducible genes, is important to improve the drought stress tolerance of crops.Broomcorn millet (Panicum Miliaceum L.) is an old crop that originated in China and plays very important role in the civilization of China. It is still a major crop in arid and semi-arid area of northern China. The crop has the advantages of drought resistance, grown well in barren soil and higher water usage efficiency (WUE), which make it a valuable gene resource to improve WUE of the staple crop, such as wheat, maize and rice. Some progress has been made to understand the mechanism of broomcorn millet'drought resistance on physiological and biochemical level, however the knowledge of molecular mechanism on drought resistance of the crop is still very few. The aim of this work is to reveal the molecular mechanisms of drought resistance and rehydration by means of cDNA-AFLP and Suppression Subtractive Hybridization (SSH) during drought and rehydration progress of broomcorn millet, and the emphasis is on the rehydration progress. The main results are as follows:1.cDNA-AFLP (cDNA Amplified Fragment Length Polymorphism) was used to analyze genes differentially expressed in broomcorn millet seedling under the condition of normal watering, serious drought and rehydration. All of the 36 primer pairs used in the selective amplification could amplify differential expression profile among the samples. The total number of amplified fragments of the three samples is check>rehydration>drought.Twelve fragments only presented in serious drought or rehydration were selected, cloned and sequenced. Based on the Blastx search to NCBI non-redundant protein database, one fragment was similar to UDP-N-acetylglucosamine-N-acetylmuramyl-(Pentapeptide), two fragments had significant homologous with rice retrotransposons, another two had significant homologous with two hypothetical proteins.