Discovery Of A High-stalk Dominant Mutant In Tetraploid Wheat And Correlation Analysis Between Its DELLA Protein Abundance And Plant Height

Wheat is an important food crop in China. Therefore, breeding good varieties ofwheat appears more and more significant. Discovery and exploitation of dwarf geneshave produced tremendous effects on world wheat production, initiating the worldfamous “Green Revolution”. So far,21dwarf genes have been discovered anddesignated, but only four dwarf genes were cloned. Genetic analysis demonstratedthat the four dwarf genes were belonging to DELLA gene family. It had the functionof control plant height and good representation in the research fields of plant stressresistance. In this study, we found a dominant Tetraploid wheat mutant withhigh-stalk which was associated with DELLA. We think that this material has crucialtheoretical significance and key application value in wheat breeding.1. Tetraploid wheat materials (xi’an sui fen zhi and Gerando) don’t have Dchromosome, simultaneously, there are no Rht genes in the A chromosome, so thematerials is advantage for Rht study. each of them that xi’an sui fei zhi and Gerandowheat materials includes wild-type and mutanted Rht1gene using a type of specialpromer testing, respectively. Previous research has shown that the wild type gene ofRht1with phenotype of high hypocotal, and the mutant have an effect of24%reducing the plant height.2. The conventional genetic studies showed that dominance degree is0.81inthe F1combination of xi’an sui fen zhi, we think the material have Rht regulatorygenes; there are22.8%plants with a trait of transgressive segregation in F2combination of xi’an sui fen zhi, but previous research results considered Rht1genehad an effect of24%reducing height, simultaneously, the high segregation posterityof BC1combination are higher than the high parent material, thus we think that thereis a pair of dominant and regulatory genes in this Tetraploid wheat materialcontrolling the accumulation of DELLA protein. 3. In the study, we found a regulatory mechanism between the dominant gene ofxi’an sui fen zhi and DELLA protein. Its repress wheat growth by control theaccumulation of DELLA protein which less in high plant and more in short stalkedplant, and the expression of DELLA protein showed positive correlation with thechanging of its tanscription level. this dominant gene does not directly regulate thedegradation of DELLA protein. In addition, the experiments of GA treatment showedthat the height of xi’an sui fen zhi is negative correlation with the concentration ofGA, that the phenotype of first leave of material with GA treatment is shorter thanmaterial without GA treatment and in contrast to the phenotype of Chinese Spring.Therefore, we hink that this regulatory roles of the dominant gene may be associactedwith the level of bioactive GA.