Preliminary Function Analysis Of MinE Gene And Determination Of Tapioca Starch Content

The MinE protein plays an important role in plastid division.In this study,the MinE gene was isolated from the cassava(Manihot esculenta Crantz)genome and carried out related bioinformatics analysis.And the specific expression analysis of MinE gene in different parts of cassava was detected.High quality and quantity protoplasts were isolated and succeed in performing the transient expression of the GFP-fused Manihot esculenta MinE(MeMinE)protein in cassava mesophyll protoplasts.The transient expression of MeMinE-GFP in cassava protoplasts showed that the MeMinE protein was located in the chloroplast.Due to the abnormal division of chloroplasts,overexpression of MeMinE proteins in cassava mesophyll protoplasts could result in fewer and smaller chloroplasts.Overexpression of MeMinE proteins also showed abnormal cell division characteristics and minicell occurrence in Escherichia coli caused by aberrant septation events in the cell poles.The recombinant engineering bacteria pCAMBIA1300-eGFP-MeMinE was transformed into the somatic embryo of SC8 to obtain seedlings containing the recombinant vector pCAMBIA1300-eGFP-MeMinE.In this study,the shapes,diameters,and molecular weights of cassava and potato starch granules were compared.The cassava starch granules generally exhibited a polyhedral and truncated shape,while the potato starch granules exhibited a regular,elliptical shape.The diameters of the cassava starch granules were mostly between 0-20 ?m while the diameters of the potato starch granules were mostly between 7-40 ?m.The average diameter of the cassava starch granules was over 20 ?m smaller than that of the potato starch granules.The molecular weights of amylose and amylopectin from cassava and potato starch were also quite different.All of these differences directly or indirectly led to differences in the ability of cassava and potato starch to bind with iodine,ultimately resulting in a different standard curve for use in the measurement of starch content.Finally,when the starch content of the cassava samples was measured by a dual-wavelength method(using potato starch as a standard),the measured amylose contents were 5.31%-29.59%higher than the corresponding theoretical values,the amylopectin contents were 15%-209.9%lower than the corresponding theoretical values,and the final measured total starch contents were 8.29%-115.85%lower than the corresponding theoretical values.The final results show that when measuring the starch content of cassava samples by the dual-wavelength method,only the cassava starch can be used as a standard to generate a standard curve.