An EIN3/EIL Family Gene,ZmEIL9 Regulates Grain Development in Maize
[Objective]Grain size and weight are the important factors affecting the yield of maize.The EIN3/EIL gene family is a sort of key transcription factors in the ethylene signaling transduction pathway,and the functions and regulatory mechanisms of the EIN3/EIL gene ZmEIL9 were analyzed in maize kernel development to elucidate its molecular mechanisms.[Method]The expression patterns of ZmEIL9 in maize kernel at different developmental stages were analyzed by bioinformatics and RT-qPCR.The multiple sequence alignment of ZmEIL9 and its homologs from different species was performed,and the phylogenetic trees was constructed based on the neighbor-joining method.The sequence characteristics of ZmEIL9 protein were analyzed,and subcellular localization of ZmEIL9 was performed.The insertion mutants of Mu transposon and CRISPR/Cas9 knockout mutants of ZmEIL9 were screened,and the agronomic traits including grain filling rate,storage substances such as starch granule and protein content were analyzed.[Result]According to the members of EIN3/EIL family in maize,phylogenetic trees showed that ZmEIL9 was closely related to ZmEIL1 and SbEIL1.In the transcriptomic database of maize inbred line B73,the expression levels of ZmEIL9 were higher in the grain at early and late developmental stages.However,the expression levels were higher in inbred line N04 at the middle and late developmental stages.ZmEIL9 encoded 644 amino acids in the inbred lines Dan232 and N04,while its homolog in inbred line B73 has 642 amino acids.Subcellular localization analysis indicated that ZmEIL9 was localized in nucleus.The ZmEIL9 mutants with different Mu transposon insertion sites and CRISPR/Cas9 knockout mutants with amino acid frameshift mutations were obtained,respectively.The plant height,grain length,and 100-grain weight of Mu mutants and knockout mutants were significantly lower than those of its wild counterpart.The grain dry weights at different developmental stages were also analyzed,and the grain filling rates of Zmeil9 mutant were lower than those of the wild type.The starch granules of Zmeil9 mutant were significantly smaller and had an irregular shape based on scanning electron microscopy(SEM)observations.The contents of total starch and the concentration of zein protein in the Zmeil9 mutant were significantly lower than those in the control.[Conclusion]ZmEIL9 plays an important regulatory role in the kernel development of maize.
maize(Zea mays L.)EIN3/EIL familyZmEIL9grain developmentbiology function
国家科技期刊平台
NSTL
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