Physiological Response And Proteomics Of Buchloe Dactyloides Shoots And Roots Under Different Photoperiods

Circadian clock is an endogenous mechanism of plants,it makes the plant life activities synchronize with environmental diurnal changes and improve the efficiency of plant use of environmental resources.The response of plants to different photoperiods and related protein regulatory network is not known.In this study,Buchloe dactyloides was used as the experiment material,set 12L/12 D photoperiod as the control,set the treatment 6L/18 D and 18L/6D photoperiods,measured the dynamic trends of physiological indexes under three photoperiods,and use the proteomics technique to study the proteomes of Buchloe dactyloides shoots and roots.Exploring the plant physiological and proteomic response to different photoperiods,the main result were as follow:(1)The chlorophyll content,cell membrane permeability,MDA(malondialdehyde)content,SOD(superoxide dismutase)activity,POD(ascorbate peroxidase)activity and CAT(catalase)activity of Buchloe dactyloides had daily rhythm,and the dynamic trends of physiological indexes under different photoperiods were changed.(2)Compared with the 12L/12 photoperiod,the SOD and CAT activities in the shoot and root cells of 6L/18 D and 18L/6D photoperiods are increased.SOD and CAT play an important role in plant antioxidant protection system.(3)4717 proteins were identified in the shoots and roots of Buchloe dactyloides in three different photoperiods,and there were 1103 proteins with significant changes(upregulation was more than 2 fold or downregulation was less than 0.5 and P value was less than 0.05).Compared with 12L/12 photoperiod,under the 6L/18 D photoperiod there were 198 proteins significantly up-regulated and 197 proteins significantly down-regulated,and under the 18L/6D photoperiod there were 389 proteins significantly up-regulated and 319 proteins significantly down-regulated.(4)The results of the GO(Gene Ontology)annotation showed that the proteins are affected by the photoperiod are located in the membrane lipids and organelles of the cells,and they mainly have molecular functions such as antioxidant activity,signal recognition particles,and transporter activity,and they are mainly involved in plant carbon metabolism,response to stimulation and biological regulation and other pathways.(5)KEGG pathway analysis revealed photosynthetic pathways,photosynthetic-antenna protein pathways,oxidative phosphorylation pathways,carbon-fixed metabolic pathways of photosynthetic,glyoxylate and dicarboxylic acid metabolic pathways,peroxisomes,and phenylpropanoid biosynthetic pathways,MAPK signaling pathway and plant circadian rhythm pathways showed protein enrichment,and played a major role in Buchloe dactyloides response to different photoperiod.In summary,preliminary studies were conducted on physiological indexs and proteomic changed in Buchloe dactyloides shoots and roots under different photoperiods.Photoperiod changed,and the rhythmical change trend of each physiological index changed.Photosynthesis,photosynthesis carbon fixation,oxidative phosphorylation,and circadian rhythm of Buchloe dactyloides are used to adjust to the new photoperiod.Under the photoperiod of 6L/18 D and 18L/6D,the active oxygen scavenging system of shoots and roots to reduce the cell damage caused by the photoperiodic changes.plant adjusts the photosynthetic rate and circadian rhythm to adapt to the new photoperiod and maintain the growth of plants.