Construction Of CRISPR/Cas9 Knockout Mutants Of 14 Genes Controlling Yield,Plant Architecture And Heading Date In Rice

Plant architecture,heading date and yield are complex quantitative traits controlled by multiple genes.After long-term efforts,scientists have successfully cloned hundreds of genes that control yield,heading date and plant height,but the coordination control mechanism how these genes coordinately control the phenotype is unclear.Scientists used to cross different single segment substitution lines(SSSL)to study the interaction between non-allelic genes,which not only bring amounts of work,but also take a lot of time.CRISPR/Cas9 gene editing technology enabled us to make site-specific modifications to the known genes,which produce new allelic combination.In this work,we constructed fourteen CRISPR/Cas9 vectors for yield-associated genes(including Hd3 a,Sd1,Gn1 a,Os MADS51,Ghd7,Ghd8,TAC1,Hd1,GW6 a,Nal1,Ehd1,Os PRR37,DEP1,GNP1)and transferred to Huanghuazhan,Kasalath,Chujing37,respectively.In addition,we constructed thirty-two vectors that combined two genes controlling the same agronomic trait and transferred to Huanghuazhan,Kasalath,Chujing 37,respectively.So far,we get all of the transgenic positive plant of 144 lines.The sequence of corresponding gene in 144 lines have changed with 1-bp or 2-bp Indel compared to wild-type,which result in the loss of function of genes.It is consistent with previous study that the heading date delayed 27 days in wild plant than in osprr37-HHZ mutant in long day,indicating that Os PRR37 has been knocked out successfully.It is important for research of non-allelic interaction in the same genetic background to establish the important QTL genes knocked out lines.It will contribute to analysis the complex agronomic trait and exploit new resources using existing resources.