Analysis Of Specific Expressed Genes From Wild Species In Sugarcane Cultivars

Modern sugarcane cultivars(Saccharum spp.) are transgressive interspecific hybrids with complex polyploid genetic backgrounds, and the major components of the genome derived form S. officinarum, and the remainder form other wild species such as S. spontaneum, S. barberi, etc. We further screened specific expressed sequences of wild species and analysed genetic structure and potential function of them using gene chip technology, and revealed the expression role and contribution of wild species consanguinity in the offspring of sugarcane hybrids at different growth stages(seedling stage, tillering stage, elongation stage, and mature stage). Through this project, new scientific basis will be provided for the genetic analysis, germplasm identification, parent and progeny selection for nobilization breeding; the foundation will be laid for the isolation, cloning and transformation of the exogenous functional genes of sugarcane. The results were as fellows:1. There were respectively1715,2003and1577different expressed genes at seedling stage,2307,2106,2317at tillering stage,1245,2866and2562at elongation stage,1766,1851and1388at mature stage from S. spontaneum, S. robusfum and S. barberi compared respectively with S. officinarum by using Sugar Cane Genome Array. We obtained the specific expressed genes at different growth stages from one of the wild species compared with other species, there were66,63,53genes at seedling stage,21,42,71genes at tillering stage,88,79,77genes at elongation stage,76,50,41genes at mature stage from S. spontaneum, S. robusfum and S. barberi. We also obtained293,195,188,239common specific expressed genes from2or3wild species at seedling stage, tillering stage, elongation stage and mature stage, respectively.2. There were respectively68specific expressed genes at seedling stage,102at tillering stage,195at elongation stage,22at mature stage from wild species in sugarcane cultivars (ROC22, Yuetang93-159, Liucheng03-182), and the different cultivars had different numbers of expressed genes; the common genes at elongation stage from the three cultivars, most of them came from the S. robusfum, S. barberi, and the common genes at seedling stage, tillering stage and mature stage, most of them came from the wild species. Specific expressed genes from wild species had all expressed at different period of growth stage, there were24genes had expressed at two periods of growth stage,6at three period of growth stage, and4at four period of growth stage, respectively.3. The function of the specific expressed genes from wild species in sugarcane cultivars at different period of growth stage was analysed, mainly involved in plant growth, stress resistance, sugar synthesis. 4. Gene expression profiling of S. officinarum and S. spontaneum at the elongation stage was analyzed using Solexa sequencing. Using Solexa sequencing,42913194and39363668tags from S. officinarum and S. spontaneum were gained respectively. Of which143121and112281clean tags were obtained corresponding to25164and20349distinct clean tags,117957and91932unknown clean tags respectively.1432differentially expressed genes were observed using Solexa sequencing. The functions of these genes were mostly related to abiotic stimulus response, phosphorus metabolic process and regulation of transcription.