Study Of Physiological And Biochemical Changes And Preliminary Exploration About Proteomics On Dormancy Duirng Photopeirodic Induction In Greenhouse Peach

The bud dormancy in perennial plants is a temporary stagnation during growth anddevelopment, which formed during a long evolutional process, is a biological adaptability tothe changes of environmental factors and different seasons. In particular, the characteristicfeature is not only of biological and ecological interest in survive and multiplication ofspecies, but of important application value in agricultural facilities production. The produc-tion of facilities fruit tree had been an important branch of fruit tree production, dormancy isone of key factors to limit the forcing production of facilities fruit tree. So the regulationstudy on dormancy process of facilities fruit tree has an important realistic significance, whichcan regulate the mature period of fruit tree. Proteomics make all the proteins of the organ ortissue as the research objects, understand the laws of science life activities from the overalllevel. Protein expression and function mode in peach tissues could be analyzed by studying itschanges under different photoperiod conditions.Differential photoperiods (long day and short day) were set up to investigate the role ondormancy process and physiological changes in6-year-peach [Prunus persica cv. Chunjie]leaves and buds during dormancy induction. At the same time, characteristics of proteinexpression were analyzed by using high-throughput proteomics technology platform, and thedifferentially expressed proteins and their functional group were revealed.The main results were as follows:1. Short day (SD) can induce buds to natural dormancy significantly,1week earlier thannatural condition (CK), long day (LD) delayed the occurrence of induction. The dormancyinduction process was phased development.2. Soluble sugar and soluble protein were decreased, and starch content was increasedduring dormancy induction period. LD favored to reduce the starch content and the decreasingamplitude of soluble sugar and soluble protein. SD played contrary roles.Totle water content, free water content and the contribution rate of it to totle watercontent were decreased, bound water and the contribution rate of it to totle water content wasincreased during dormancy induction period. LD treatment increased SOD and CAT activities,bound water and the contribution rate of it to totle water content, proline contents in leaves in late stage of induction period, decreased MDA content and injury rate, which performance outof the strong resistance. The leaf resistance of SD treatment responsed rapidly, the durationwas short, however.3. Net photosynthetic rate, stomatal conductance and photosynthetic enzyme activityreduced, intercellular CO2concentration rised, and Rubisco degradated during dormancyinduction, which indicated that the reason of photosynthetic rate decline was due to thedeterioration and activity decrease of photosynthetic enzymes, which was non-stomatalfachtors. Photosynthetic performance in short-day leaves was lower than the natural leaves,the main reason was the manganese stabilizing protein/photosystem â…¡ polypeptidesuperfamily-like protein is downregulated.Activities of the C4pathway key enzyme PEPC and the C3pathway key enzyme RuBPCwere reduced in dormancy induction period. The ratio of PEPC/RuBPC in LD leaf was lowerthan CK significantly or very significantly, the SD was higher than that of CK. Photosyntheticpathway was speculated tend to the C3pathway under long-day conditions and the C4pathway under short day.4. PPP respiration in substrate oxidation level and alternative pathway respiration in electrontransfer pathway level was increased during dormancy induction, and the contribu-tion rate tothe total respiration rate increased, which were the remarkable characteristics of dormancyinduction. The two different types of respiration rates of SD treatment higher than that of CK,LD treatment contrarily. According to the respective contributions of the respiration pathwaysto the total respira-tion rate, TCA cycle and cytochrome electron transport pathway were stillthe main pathways of substrate level and electron transport level respectively.5. The2-DE system was conducted to be suitable for peach leaves and flower buds byusing TCA-acetone precipitation method. The gels were analyzed by ImageMasterTM2DPlatinum software. More of500reproducible protein spots were detected, among which65protein spots were differential in both leaves and flower buds (the criterion was thedifferential protein spots changed their intensities significantly (P<0.05) by more than2.0folds),42differential protein spots were identified by MALDI-TOF/TOF MS and databasesearching. Which were classified into8groups: regulation of biological process; cellularprocess, part and regulation; response to stimulus; metabolic process; macromolecular complex and organelle part; localization, transporter activity; catalytic and/or antioxidantactivity, unknown protein. This study initially cleared that some types, expression andfunction of proteins involved in photoperiodic dormancy induction, which provided basis forrevealing peach response and process regulation to photoperiodic induction mechanism ofdormancy.