Cloning And Functional Analysis Of LpMYB1 And LpMYB11 Genes In Lilium Pumilum

Lilium pumilum has both ornamental,edible and medicinal value,and has salt and drought resistance.It is an important parent of lily breeding.In this study,23 transcription factors were screened from the transcriptome of Lilium pumilum and named LpMYB1-23,and then the MYB transcription factor family protein physicochemical properties analysis,conserved motif analysis,family phylogenetic analysis,protein advanced structure analysis,Conserved domain analysis,expression pattern analysis under different stresses,the results are as follows:1.The number of amino acids in MYB protein of Lilium pumilum is between 100-570,the molecular weight is between 11349.89-46229.91 k Da,and the isoelectric point is 4.85-10.4.The hydrophobicity of MYB protein of Lilium pumilum was between-1.101 and 0.891.Most MYB proteins of Lilium pumilum were hydrophilic proteins,only LpMYB2,LpMYB4 and LpMYB16 were hydrophobic proteins.In terms of protein stability,LpMYB16 and LpMYB18 are stable proteins,and other MYB proteins are unstable proteins.A total of 3 conserved motifs were detected in the full-length amino acid sequence of LpMYBs.Most LpMYBs have three conserved motifs with similar positions.Among them,LpMYB12 and LpMYB21 only contain one conserved motif,LpMYB18,LpMYB 16,LpMYB15,LpMYB13 Contains two conserved motifs.Phylogenetic analysis showed that R2R3-MYB transcription factors(including LpMYB13,LpMYB15,LpMYB16,LpMYB17,LpMYB18,LpMYB19,LpMYB20,LpMYB21,LpMYB22,LpMYB23)were mainly distributed in class I,accounting for the total R2R3R-MYB transcription factors of Lilium pumilum.70% of 1R-MYB(including LpMYB2,LpMYB3,LpMYB4,LpMYB1,LpMYB5,LpMYB6,LpMYB7,LpMYB8,LpMYB9,LpMYB10)are mainly distributed in class II,accounting for 50% of the total 1R-MYB class transcription factors in Lilium pumilum.The 1R-MYB class of transcription factors has the widest distribution on the evolutionary tree due to its structural diversity.4R-MYB class transcription factors(including LpMYB11,LpMYB12,LpMYB14)are mainly distributed in class I.Most of the MYB proteins of Lilium pumilum are mainly random coils,and LpMYB11,LpMYB7,LpMYB15 and LpMYB12 proteins are mainly α-helix,and random coils,β-sheets and β-turns are distributed in the protein sequence.The tertiary structures of MYB proteins of Lilium pumilum are very similar,and the tertiary structures of 1R-MYB proteins are obviously more complex than those of 4R-MYB proteins.2.By analyzing the expression patterns of 23 MYB genes in the roots,stems,and leaves of Lilium pumilum The expression was significantly up-regulated in the stem,and the genes up-regulated in the stem were less.3.Two genes,LpMYB1 and LpMYB11,were cloned.The length of the open reading frame of LpMYB1 was 795 bp,which could encode 264 amino acids.The phylogenetic tree analysis showed that the highest homology with papaya was 83.7%;the length of the open reading frame of LpMYB11 was It is 516 bp,can encode 171 amino acids,and has the highest homology with soybean MYB protein,and the homology reaches 73.47%.Both LpMYB1 and LpMYB11 belong to the MYB gene family.4.The analysis of salt resistance of transgenic plants with LpMYB1 and LpMYB11 genes showed that the root length and fresh weight of wild-type tobacco seedlings changed more than that of transgenic tobacco under salt stress;The MDA content and relative conductivity of LpMYB1 and LpMYB11 transgenic tobacco were significantly lower than those of the control;The contents of chlorophyll and proline and the activities of antioxidant enzymes(POD,SOD and cat)in transgenic tobacco with LpMYB1 and LpMYB11 genes were significantly higher than those in the control.These results showed that LpMYB1 and LpMYB11 genes improved the salt tolerance of tobacco.