The Expression Analysis Of Gene And Protain In Mulberry Under Drought Stress

Mulberry, one of the most important production forests, is a suitable nature feed forsilkworm with strong environmental adaptability. Drought stress is a normally abiotic stressall over the world. The understanding about drought resistance formation in mulberry willcontribute to new varieties breeding and drought tolerance enhancement. In this study,weused Shin-Ichinose to achieve rapid propagation, then cDNA-AFLP technology andtwo-dimensional electrophoresis were used to analyze alterations of gene and proteinexpression profiling, respectively. Candidate genes and proteins were revealed whichprovided molecular evidence for further research on drought stress of mulberry. Thisexperiment was consisted of three parts:1Tissue culture and rapid propagation of Shin-Ichinose:Tissue culture is an effective method to breed plants in industry, also a basic technologyto establish research materials’ system in laboratories. Based on reported rapid propagationprojects of different mulberry varieties, We optimized different stages’ prescriptions tocultivate Shin-Ichinose successfully. The result showed that the bud Sprouting medium ofMS+6-BA0.5mg/L+IBA0.1mg/L,the initially generation medium of MS+6-BA2.0mg/L+NAA0.1mg/L, the subculture medium of MS+6-BA2.0mg/L and the rooting culture mediumof1/2MS+NAA1.0mg/L will be the most suitable progress to achieve rapid propagation ofShin-Ichinose.2The changes on physiological and gene expression profiling of Shin-Ichinose underdrought stress:We treated Shin-Ichinose without water supply for9days, then rewatered plants.Indexes such as chlorophyll, Malondialdehyde(MDA) and proline(Pro) contents influenceshad been measured during this period. We found that chlorophyll had a downtrend evenrewatered9days later, however the contents of MDA and Pro rose remarkably along withseverer drought and decreased after watering.We also used cDNA-AFLP technology to select drought-related transcript-derivedfragments(TDFs).16TDFs were uncovered and homology with known genes aftersequencing and blasting in NCBI database. These ESTs were similar with gibberellin20 oxidase, glutathione reductase, oligopeptide transporter, DNA binding protein,18S ribosomalRNA gene and so on. As the mulberry genome hasn’t been published, we presumed theseTDFs were involved in drought response which provided candidate genes for further study.3The changes of protein expression profiling in Shin-Ichinose under drought stressIn this study, Two-dimensional electrophoresis of protein（2–DE）has been used toanalyze changes on protein expression under rapid drought treatment by polyethyleneglycol(PEG).The result showed that45protein spots had significant changes：Compared withcontrol group,25spots were up-regulation including8spots only exited in treat group，20spots were down-regulation with12spots exclusively expressed in control group.5spots havebeen identified by MALDI-TOF-TOF, then3spots were relevant to peroxide elimination,protein metabolism and biosynthesis, respectively. Another spot contained two conserveddomains named UBN2and DUF1664. UBN2domain was the binding site of nucleic acid andZn iron to active down-regulation molecular. This result provides basic theory for furtherresearch on drought resistance formation of mulberry in protein level.