| Biological technique has displayed tremendous potential in the improvement of crop breeding.But the improvement of wheat breeding with biological technique is very slow,the main reason is that genetic background of wheat is very complicated so the regenerative ability of the explant is very feeble during the course of tissue culture.In order to explain the mechanism of dedifferentiation,we bring forward"the acid-alkaline dedifferentiation hypothesis".And in order to testify the hypothesis,we do the research with the mature embryo.We have determined hydrotic activity of the plasma mambrane H~+-ATPase and the expression changement of plasma mambrane H~+-ATPase gene during the dedifferentiation.We prove the function of the plasma mambrane H~+-ATPase on the physiological and molecular level to provide evidence for the"the acid-alkaline dedifferentiation hypothesis".1.There are differences between the wheat mature embryo cultured on the culture medium with and without 2,4-D. The wheat mature embryo on the culture medium with 2,4-D produces callus,and the wheat mature embryo on the culture medium without 2,4-D is just in bud.2. The result of gene chip displayed in both callus from mature embryo and young embryo,the gene of 14-3-3 protein achieve the expression max after 2 hours and the gene of plasma membrane H~+-ATPase achieve the expression max after 6 hours.3. The result of fluorescent quantitive PCR also revealed that the gene of plasma membrane H~+-ATPase from wheat mature embryo cultured on the culture medium with 2, 4-D achieves the max value after 6h.This result is consistent with gene chip.4. The hydrolytic activity of the plasma membrane H~+-ATPase from the mature embryo on the MS culture medium with 2mg/L 2, 4-D achieves max value after 24h,and then goes down.But The hydrolytic activity of the plasma membrane H~+-ATPase from the mature embryo on the MS culture medium without 2mg/L2,4-D ascends between 0 and 72h.All the results above reveal that perhaps auxin induces wheat mature embryo entering dedifferentiation though 14-3-3 protein.It induces the expression of 14-3-3 protein firstly,and 14-3-3 protein can aroses the expression and the hydrolytic activity of plasma membrane H+-ATPase. |
