ZHANG Jing-Jie, PAN Bing-Bing, ZHU Pan-Pan, PAN Qi, ZHANG Mian, XIAO Qiao-Qiao
The MYB protein family is one of the largest transcription factor families in plants, widely involved in growth and development, stress responses, and secondary metabolism. However, the MYB protein family members in Lonicera japonica have not been identified yet. In this study, a genome-wide identification and analysis of the MYB protein family in L. japonica was conducted using bioinformatics methods, covering basic physicochemical properties, phylogenetic trees, gene structures, conserved motifs, and cis-acting elements. Additionally, the subcellular localization of MYB6, MYB106d, and MYB114 proteins was detected through the construction of pCAMBIA1300-GFP fusion vectors and transient transformation in Nicotiana benthamiana leaves. The results showed that a total of 147 LjMYB genes were identified, belonging to 17 subfamilies (S1-S17). The encoded amino acid lengths ranged from 52 to 1 060 AA, isoelectric points from 4.42 to 11.52 pI, and the number of exons from 1 to 13, with molecular weights ranging from 6 086.3 to 119 075.08 kD. MEME analysis revealed that the number and distribution of motifs in different MYB proteins varied, while the structural features within the same subfamily were similar. The analysis of cis-acting elements indicated that the promoter regions contained light-responsive, hormone-responsive, and biotic and abiotic stress-related elements and binding sites. Chromosome distribution showed significant genome doubling of MYB genes (possibly related to chromosome evolution doubling). The collinearity analysis of MYB genes between L. japonica and Arabidopsis thaliana revealed 121 pairs of homologous genes distributed across all A. thaliana chromosomes, demonstrating evolutionary conservation. Expression profile analysis indicated that L. japonica MYB genes played different roles in growth and development and had varying sensitivities to different light intensities. Subcellular localization showed that LjMYB6, LjMYB106d, and LjMYB114 were all localized in the nucleus. In conclusion, the MYB protein family in L. japonica has diverse biological characteristics and may be involved in growth and development, hormone regulation, and biotic and abiotic stress responses.