| Corn is the highest yield,the most widely planted grain crop.In the Huang-Huai-hai grain producing area,the special wheat-maize rotation cropping system is used in grain production.Under the condition of stable yield,the early maturity of corn will accelerate the dehydration of corn,which is conducive to the development of mechanized corn harvest.The shortening of the growing period of maize is of great significance to the selection of sowing time,the extension of growing time and the increase of yield of wheat.Therefore,the study of maize growth period is of great significance to improve the growth period of maize varieties and optimize crop planting pattern.According to Zm IAA29,a transcription factor encoding gene associated with maize growth period,obtained by pre-transcription factor GWAS,this study used Zm IAA29 as the target gene to construct and transform overexpressed maize transgenic material with maize inbred line KN5585 as the background.After many years of plant identification and phenotypic observation at multiple sites,combined with relevant validation tests,the following conclusions were obtained.1.Compared with the control,the growth period of Zm IAA29 overexpressed materials was significantly advanced,and the tasseling stage,powder stage and silking stage were advanced by 2-3 days on average.Compared with the control,the yield per ear of Zm IAA29 overexpressed materials did not decrease,the row number and row number of ears were significantly more than the control,the grain size was significantly less than the control,and the average number of grains per ear was increased by 68.45.The apical meristem of overexpressed Zm IAA29 and control materials was observed by a type of microscope,and the development stage of the apical meristem of overexpressed materials was earlier than that of control.2.During the growth to V6 of maize Zm IAA29 overexpression material(T2),the apical meristem was taken and total RNA was extracted.The expression level of Zm IAA29 in the overexpressed material was determined to be much higher than that in the control by fluorescence quantitative RT-PCR,that is,the exact overexpressed material was obtained.For Zm IAA29 overexpression of materials of the apical meristem total RNA transcriptome sequencing,with padj value of 0.05 or less,| log2 FC | 1 or more as threshold of differences in genetic screening,get 4725 differentially expressed genes,in which 2200 genes expressed in a material increase in expression,2525 genes were expressed.GO enrichment analysis showed that differential genes were mainly concentrated in the generation of mature m RNA,the number and structure development of flower organs,and the development process of cells.KEGG analysis revealed that these differentially expressed genes were mainly involved in regulatory pathways including plant circadian rhythm,protein family signaling and cellular processes,amino acid metabolism,carbohydrate metabolism,and other metabolic processes.3.Since Aux/IAA family proteins often combine with ARF family proteins to generate Aux/ IAA-ARF complex,which plays a role in transcriptional regulation,ARF transcription factors interacting with Zm IAA29 were screened and verified.The interaction between Zm IAA29 and Zm ARF2,Zm ARF7,Zm ARF15,Zm ARF19 and Zm ARF25 was verified by the method of yeast two-hybrid point-to-point interaction.BILUC was further used to verify the intracellular interaction,and it was confirmed that Zm IAA29 interacts with Zm ARF2,Zm ARF7 and Zm ARF25.4.Combined with the existing data of Zm ARF7 and Zm ARF25 transcription factors DAPseq and the transcriptomic data obtained in this study,it was found that related differentially expressed genes were mainly involved in plant hormone signal conversion,environmental information processing,signal transduction,metabolism and other processes.The genes of Zm HB53,Zm MADS6,Zm MYB43,Zm MYB93 and Zm CCD7 were closely related to flowering time,seed setting and hormone signal response of maize. |
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