Comparative Analysis Of Proteomic And Anatomical Changes In The Root Tips Of Wild (Glycine Soja) And Cultivated (Glycine Max) Soybean Seedlings

To investigate the underlying mechanism of soybean root variation and identifykey genes involved in the evolution of soybean root system during domesticationprocess, we selected wild soybean, soybean landraces and soybean cultivars withbroad geographical and ecotypic representation from previouly studied soybeanmaterial, systematically studied the differences in the anatomy and the expression ofthe proteins among these three groups of soybean, and analyzed the relationshipbetween protein expression differences and the anatomical differences. The primaryresults are listed as follows:1.Junction between the region of elongation and the region of maturation of theroot tips of18soybean accessions including wild soybean, soybean landraces andsoybean cultivars from Heilongjiang, Shandong, Jiangsu, Sichuan, Yunnan, Guangxiprovinces were paraffin embeded and cross sectioned. It is shown that all of the roottips of wild soybean, landraces and cultivars are composed of epidermis, cortex,vascular cylinder, no significant difference was observed among the the anatomicalstructure of the3soybean groups. On the other hand, it is detected that the rootdiameter, the vascular cylinder diameter and the number of cortical cell layers aresignificatntly increased in in cultivated soybeans compared with the wild soybean,indicating better capability of absorption, transportation and support in cultivatedsoybeans.2. Root tips (0.8cm in length) of41wild soybean accessions (wild soybeangroup),44soybean landrace accessions (soybean landrace group) and44soybeancultivar accessions (soybean cultivar group) were selected respectively to performtwo-dimensional electrophoresis (2-DE) analysis.122-DE images were obtainedfrom4repeats of the2-DE of each soybean group (group match rate upto80%). Anaverage number of769protein spots were detected on each2-DE image analyzedwith ImagMster6.0software.38differentially expressed protein spots (4.96%of thetotal protein spots) were screened based on the one-way ANOVA (P <0.05) test and the LSD test (P <0.05), as well as the criteria that the ratio of relative spot volume（%Vol）1.5.35of the38proteins were identified from the NCBInr database.3.We analyzed the35identified proteins biostatistically. The spatial structureand presumable functions of these proteins were predicted from Phytozome, ExPASy,UniProt, MODBASE, Pfam, Panther, KOG and KEGGORTH, indicating that thedifferentially expressed proteins in the root tips of wild and cultivated seedlings aremostly involved in the NADP(H) oxidation-reduction, the TCA cycle, the electrontransport chain and other processes associated with energetic metabolism.Correspondently, GO analysis of these proteins showed that the molecular functionand biological processes of the genes encoding them are categorized as binding andcatalytic fuctions in cellular and metabolic processes.The relationship between thesedifferentially expressed proteins and energy metabolism remains to be further studiedin wild soybean and cultivated soybean seedling apical anatomy.