Genome-wide identification of KNOX gene family and exploration of candidate genes regulating stamen petalization in Antirrhinum majus
[Objective]The KNOX(KNOTTED1-like homeobox)transcription factor family plays an important role in plant growth and flower organ development.The KNOX transcription factors of Antirrhinum majus were identified and analyzed,and the key candidate genes regula-ting stamen petalization in A.majus were explored.[Method]The bioinformatics methods were used to identify the AmKNOX genes at the whole genome level,including gene structure,protein physicochemical properties,subcellular localization,phylogenetic relationship,chro-mosome localization,promoter cis-acting elements and transcription factor binding sites analysis.RNA-seq analysis and qRT-PCR verifica-tion were performed to explore AmKNOX candidate genes using petalized and non-petalized stamens of A.majus.[Result]A total of 11 Am-KNOX genes were identified from A.majus,all of which had four conserved regions of KNOX Ⅰ,KNOX Ⅱ,ELK and HOX and were classi-fied into Class Ⅰ(AmKNOX1,AmKNOX2,AmKNOX3,AmKNOX9 and AmKNOX11)and Class Ⅱ(AmKNOX5,AmKNOX4,AmKNOX7,AmKNOX10,AmKNOX6 and AmKNOX8).The AmKNOX protein contained 282-406 amino acids and were localized in the nucleus.Anal-ysis of promoter cis-acting elements showed that AmKNOX family members were involved in plant growth,hormonal and abiotic stress respon-ses.Moreover,AmKNOXs had a large number of transcription factor binding sites related to plant growth and development,organ differentia-tion,and physiological regulation of stress.RNA-seq and qRT-PCR analysis showed that AmKNOX family genes were significantly differenti-ally expressed in petalized and non-petalized stamens of A.majus.[Conclusion]The study identified 11 AmKNOX members,of which five positive(AmKNOX5,AmKNOX10,AmKNOX6,AmKNOX4 and AmKNOX9)and one negative(AmKNOX11)candidate genes involved in stamen petalization were ultimately identified.Among them,the expression level of AmKNOX5 gene in petalized stamens was 2703％higher than that in normal stamens,and the inference function should be particularly important.The study laid a foundation for in-depth analysis of the molecular mechanism of flower development and genetic improvement of A.majus.
万方数据
维普
