Research Of Floral Bud Differentiation, Endogenous Pytohormones And Differentially Expressed Proteins Of Cucumber Cotyledonary Nodes Treated With Paclobutrazol

The mechanism of flowering has been one of the hot topics of plant developmental biology. Hormone plays an important regulative role during plants.flowing .The research on the action mechanism of plant hormone is one of the important constituents of Proteomics studies.Paclobutrazol (PP₃₃₃) is the inhibitor of gibberellins (GAs) biosynthesis. PP₃₃₃ can promote the floral differentiation of cucumber cotyledonary nodes, and induce the change in endogene hormone under suitable conditions. This paper studies the effect of PP₃₃₃ at the molecule level during the course of flower differentiation of cucumber cotyledonary nodes cultured in vitro by the hormone determination technology and the technology of Proteomics.The finding of the research is that the impact of the treatment of PP₃₃₃ on cucumber cotyledonary nodes is multiple: PP₃₃₃ treatment can significantly change the content of IAA, decrease the IAA level in initial stage, and in particular, the content of IAA reaches the lowest point three days after being cultured. By the treatment with PP₃₃₃; the content of GA is significantly changed and is significantly higher five days after being cultured ; the content of ZR and ABA is increased, and the content of ABA is significantly increased two days after being cultured. The ZR level in the control group shows a sudden increase on the seventh day, and this increase will be significantly inhibited by treatment with PP₃₃₃. In short, the treatment of PP₃₃₃ has not only changed the content but also the contrast between the different endogenous hormones. TIBA and PP₃₃₃ can promote the differentiation of floral buds of cucumber cotyledonary nodes.When treatment with TIBA on the differentiation of floral buds of cucumber cotyledonary nodes are cultured in vitro, the highest concentration should be less than 1.0mg/L, otherwise the cotyledonary nodes can easily curl up. Promotion is exhibited in treatment with TIBA and PP₃₃₃ on floral differentiation of cucumber cotyledonary nodes cultured in vitro, and the best coordinate concentration are TIBA 0.3mg/L and PP₃₃₃ 0.3mg/L. Two-dimensional electrophoresis showed that most of the proteins during the floral differentiation of cucumber cotyledonary nodes culture in vitro are in pH 5-6, and the treatment with PP₃₃₃ may handle the different expressions of proteins. In the protein analysis of the 12 selected points, 4 proteins increased in abundance while 8 decreased in protein abundance.