Identification And Functional Study Of Rht And TaGAMyb-Bin Wheat

Plant height of wheat is a quantitative trait controlled by multiple factors,it will be affected by genetic factors such as Rht-B1b,Rht-D1b,GAMyb and mang environmental aspects during its construction.When wheat only has Rht-B1b or Rht-D1b dwarfing genes,its plant height will reduce about 24%,and when the two are present at the same time,it will have an additive effect,with a reduction of nearly60%;what’s more,GAMyb is the key regulator in the GA signal transduction pathway.It is mainly involved in the process of seed and pollen germination and stem elongation.TaGAMyb can promote the elongation of wheat internodes and is related to plant height.TaGAMyb-B has two allelic variants which were TaGAMyb-Ba/b in different wheat materials,and the plant height of TaGAMyb-Ba allele material was significantly higher than which of TaGAMyb-Bb allele material.In this study,molecular marker detection methods were used to further study the distribution of dwarfing genes Rht-B1b and Rht-D1b in wheat varieties and their effects on plant height;secondly,we will continue to study the mechanism of TaGAMyb-B in the process of high construction.The results are as follows:（1）Among 321 wheat materials,194 materials belong to the Rht-B1b haplotype,which distribution frequency is 60.4%;135 materials belong to the Rht-D1b haplotype with a distribution frequency of 42.1%.In addition,78 of the 321 materials belong to the Rht-B1b+Rht-D1b haplotype with a distribution frequency of 24.3%.Further analysis of the population of 91 materials which has been identified plant height phenotypes finds that the materials with haplotype TaGAMyb-Bb+Rht-D1b+Rht-B1b has the lower plant height.（2）In transgenic rice,the transcript expression of TaGAMyb-B is stem>root>seed>leaf;In addition,compared with transgenic TaGAMyb-Ba rice,transgenic TaGAMyb-Bb rice is more sensitive to cope with abiotic stress;（3）T₂representative identification shows that the two,but the first,second and third stem lengths of transgenic TaGAMyb-Ba rice are lower than those of transgenic TaGAMyb-Bb rice,and the first,second and third stem diameters of transgenic TaGAMyb-Ba are significantly higher than those of TaGAMyb-Bb rice.The results of cytohistological analysis shows that the thickness of thick-walled tissue in the cross section of transgenic rice TaGAMyb-Ba is greater than that of TaGAMyb-Bb and there is a significant difference between the two（P=0.025）;the average length of thick-walled cells in the longitudinal section of TaGAMyb-Ba rice is less than that of TaGAMyb-Bb rice,there is a very significant difference between the two（P=0.00）,which is consistent with the phenotypic data.