Functional Analysis Of Se14 In The Regulation Pathway Of Brassinolide And Gene Cloning Of An Early Heading Mutant E22 In Rice

Rice is one of the most important food crops,and it is important for eliminating hunger and solving the problem of food.Heading date is one of the most important agronomic traits of rice.The yield of rice can be effectively improved by improving the heading date of rice.The brassinolide pathway can affect the development of rice in many ways,which in turn affects rice yield.In this study,agronomic traits of the mutant se14 obtained previously were verified.In order to further analysis the function of Se14,we used CRISPR/Cas9 technology to carry out fixed-point knockout experiment on Se14 gene under the background of wild-type NP.At the same time,se14 was treated with BR,and the expression of BR synthesis and signaling related genes was analyzed.On the other hand,we cloned rice early heading gene E22 by MutMap.Multiple interacting proteins of ZM17 transcription factors were screened by yeast hybrid technology.The main results were obtained following:1.The mutant se14 showed dwarfing,shortening uppermost internode length and erect leaf except that heading date was earlier than that of NP.By using CRISPR/Cas9 technology,we obtained 6 independent Se14 knockout plants,all of which had earlier heading date than wild-type NP,and showed the phenotypes of erect leaf,shorter panicle length and internode length,and lower plant height.This suggests that Se14 may have a polyploidy that can control multiple traits of rice at the same time.2.When 24-eBL was applied for treatment,the leaf angle between mutant se14 and wild-type NP were increased with the increase of the concentration,but the change range of mutant se14 was larger,and the difference reached the maximum at 1000 ng/μL concentration.We also analyzed the expression of BR synthesis and signaling pathway related genes.These results suggest that Se14 plays an important role in BR synthesis and signaling pathway,and may directly or indirectly regulate uptream regulatory factors of BR synthesis and signaling pathway,affecting rice phenotype development.3.The late-flowering mutant lvp1 with clear background in NP was mutated by EMS,and a mutant with earlier heading date than lvp1 was screened,tentatively named e22.The heading date of e22 was about 30 days earlier than that of lvp1 in Wenjiang natural field.Compared with the control lvp1,the height of e22 plants decreased significantly,the panicle length shortened,the number of grains per ear decreased.Furthermore,we cloned the early heading gene E22 using MutMap technology.4.The yeast cDNA library that has been constructed in the laboratory of our project team was used to conduct the yeast hybrid experiment on ZM17 transcription factors,and 15 candidate genes were preliminarily obtained.The success of the preliminary screening experiment laid a good foundation for the subsequent identification of the interaction proteins of ZM17 transcription factors.