Drought-related Gene Expression Analysis During Drought Stress In Rapeseed (Brassica Napus.L)

Rapeseed is not only one of the world's important oil crops but also raw material for industrial product like feed protein. But seasonal drought is a serious threat to rapeseed production in China, so selection of rapeseed germplasm to breed for drought resistance is one of the effective methods to improve the current varieties. Here we systematic studied expression level of eight genes under drought stress and analysed the mechanism of drought resistance. The main results are as followed:1. Using two drought-tolerant material, two drought-sensitive material and four moderate drought material selected from the thirty-eight Brassica napus by our group, We have determined the basic physiological and biochemical indicators and morphological parameters, e.g. relative water content, relative electrical leakage, drought-tolerant index and content of hygrogen peroxide. The results revealed that there was great difference between varieties with different drought resistance.2.Expresson profile analysis of relative genes that response to drought by different mechanism have been conducted, including osmotic stress, drought-inducing proteins, signal transduction of drought stress, polyamine metabolic process and SOS pathway. We also analysed the variation trend of expression level for those genes in Brassica napus with different drought resistance during drought stress. The results showed that the expression level of those genes were different from variety to variety.3. We also carried out the correlation analysis between the expression level of drought related genes and physiological and biochemical indicators. The results indicated that expression level of btg-26 that is drought-inducing protein of Brassica nupus is significantly correlative with relative electrical leakage and relative water content. Expression level of p5cs, a limiting velocity emzyme in proline biosythetic pathway is significantly correlative with drought coefficient, relative electrical leakage and relative water content. Badh, a limiting velocity emzyme in betaine biosythetic pathway, its expression level is significantly correlative with blade water content and sos2 which is involved in plant SOS pathway is significantly correlative with the content of hygrogen peroxide. The adc, a key emzyme in polyamine biosynthetic pathway, of which expresson level is significantly correlative with drought efficient, relative electrical leakage and relative water content. Besides, we didn't observe the any relation between physiological and biochemical indicators and drought-related genes Cam,Plc and bnd22.