Isolation Of Drought Stress Related Genes Through CDNA-AFLP Technique In Manihot Esculenta Crantz

Drought, salt, extreme temperatures, chemical toxicity and oxidative stress are unfavorable to plant growth, drought stress is the most impact on plant growth. Cassva (Manihot esculenta Crantz) is a tuberous root crop of the Euphorbiaceae (spurge family), with potato and sweet potato called three major potatos. Cassava is the sixth-largest source of crops for food in the world. As a typical tropical crop, cassava has high photosynthetic efficiency, productive, drought-tolerant, Barren resistance, is a prominent drought-tolerant crop. Currently, cassava has been researched on stress physiology, and our team has predicted a number of drought stress-related miRNA, but the drought resistance of cassava is stall noly have descriptive information, the drought-tolerant molecular mechanism of cassava has not elucidated.Use the technique cDNA-AFLP to analysis the gene’s expression during drought stress in SCI 24 of cassava. The main results are as follows:1) SC124 of cassava have been treated under drought stress, and collect plant material at 4 time points. Extract total RNA from the function leaves.2) EcoR I and Mse I restriction enzyme and 128 pairs primers were used on the SC124 variety of 4 time points of drought stress in this study.117 differentially expressed transcripts derived fragment (TDF) was obtained from about 3,500 effectively amplified gene fragments.3) Differences expression of TDFs were divided into four types,117 TDFs has obtained from cDNA-AFLP, and distributioned as follows:up-regulated expression (TypeⅠ) 49, were 41.88% share of the total sequence;down-regulated (TypeⅡ) 22, were 18.80% share of the total sequence;the first increase after the down-regulated (TypeⅢ) 26, were 22.22% share of the total sequence; the first down after the up-regulated expression (TypeⅣ) 20, were 17.09% share of the total sequence.4) 117 sequences have blastx in NCBI,8 of this are non-homologous sequences,109 are highly homologous genes, of which 62 genes have functional annotation and 47 as predicted genes or proteins. By functional annotation,62 TDFs classified to 7 class: transcription factors, energy metabolism, carbohydrate metabolism, lipid metabolism, amino acid metabolism, signal transduction, transfer of transport, genetic information processing, peptide synthesis and metabolism. 5) 19 TDFs of total were validated by RT-PCR and real-time PCR,12 of them were consistent with the cDNA-AFLP result.9 of this were energy metabolism class, lipid metabolism class, amino acid metabolism classes, signal transduction class and peptide synthesis and metabolism class. The other 3 TDFs which have identificated sequences were non-functional annotation, may be new genes without report.