Effect Of Low Temperature On Physiological Traits And Transcriptome Of Casuarina Cunninghamiana Miq. Clones

Casuarina cunninghamiana Miq., an important ecological coastal shelter forest tree species belongs to Casuarinaceae Casuarina, due to it’s sensitive to low temperature characteristic, temperature has become an important limited factor for C.cunninghamiana Miq. introduction. To explore the adaption of C.cunninghamiana Miq. in low temperature, We collected materials from Hanzhong city in shanxi Province and from Lingao city in Hainan Province and treated with artificial cooling. Identify and analyze the variation of 8 physiological and biochemical index of C.cunninghamiana Miq. from Shanxi, such as relative conductivity, MDA, etc. Through correlation and principal component analysis, we established the cold evaluation system of C.cunninghamiana Miq. Materials from Shanxi and Hainan been transcriptome sequenced application of Illumina HiSeq 2000 dual-end sequencing technology (Pair-end sequencing, PE). Transcriptome data were been analyzed according to no reference genome transcriptome sequencing Process. GO classification and KEGG enrichment pathway analysis were conduct on assembled Unigene, and some differentially expressed genes been screened, the main results were as follows:1 Cooling rate significantly negatively correlated with MDA content, and positive correlation with POD content. The cold system evaluation indicators been established: increase of MDA content, decrease of POD activity, increase of soluble Protein, increase of Pro content, increase of SOD activity.2 Transcriptome sequencing obtained 114,572,722 pieces of high quality Reads, and generates 83274 Unigene within length range from 201 bp to 17045 bp,833 bp average length and 1508 N50. Four databases, Nr, Swissport, COG and KEGG annotated Unigene 41118, representing 49.377%.3 Between Shanxi and Hannan material, GO functional annotation didn’t present significant difference, while KEGG in contrast. Shanxi material show highly enrich in pathway association with Protein metabolism. We obtained 33 differentially expressed genes, of which there are specific antifreeze protein gene family AFPs (Antifreeze Proteins) 1 piece,9 piece cold-induced gene transcription factor CBF family of a fatty acid desaturase gene, activities of antioxidant enzymes SOD gene 3 pieces, and osmotic adjustment enzyme proline gene 19 piece.Comprehensive physiological treats and transcriptome sequencing result, C.cunninghamiana Miq. from Shanxi present anti-cold characteristic perhaps own to synthesis of cold-induced transcription factor which initiates a series of cellular pathways such as by generating SOD synthase to eliminate free radical, by increasing the expression of free Proline osmotic regulation against intimidation from outside environment. In the Process, lots of enzyme gene expression.