Genome-wide Identification and Expression Analysis of MYC Transcription Factors in Cinnamomum camphora

doi:10.13560/j.cnki.biotech.bull.1985.2025-0889

Abstract

Abstract:

Objective MYC transcription factors (TFs) are core regulators of the jasmonic acid (JA) signalling pathway and play crucial roles in modulating plant growth, development, and secondary metabolism. Identification and analysis of MYC TFs in Cinnamomum camphora will provide a theoretical basis for investigating the biosynthesis of terpenoids and other secondary metabolites, as well as plant growth and development. Method Bioinformatics approaches were employed to perform genome-wide identification of the CcMYC family, including chromosomal localization, physicochemical properties, subcellular localization, phylogenetic relationships, gene structure, promoter regions, and protein-protein interaction (PPI) networks. Combined with quantitative real-time PCR (RT-qPCR), the expression patterns of the CcMYC gene family in six chemotypes of C. camphora was analyzed. Result CcMYC1-CcMYC12 were unevenly distributed across the 10 chromosomes. Proteins encoded by the CcMYC family contained 629 amino acids, an average molecular mass of 69.64 kD, and theoretical isoelectric points ranging from 5.15 to 6.69; their secondary structures were mainly composed of α-helices and random coils. Subcellular localization prediction showed that CcMYC12 was predominantly localized in the nucleus. Phylogenetic analysis revealed that the CcMYC genes were clustered into three distinct groups. Interspecific collinearity analysis indicated that segmental duplication events occurred in the CcMYC gene family, and collinear orthologs of CcMYC1, CcMYC4 and CcMYC5 were identified in Arabidopsis thaliana, Oryza sativa and Populus trichocarpa, respectively. Analysis of cis-acting elements in the promoter regions suggested that the expressions of CcMYC genes may be induced by light, diverse plant hormones, as well as defense and stress stimuli. Protein-protein interaction (PPI) analysis further revealed that CcMYC3, CcMYC7, CcMYC8 and CcMYC11 may play vital roles in regulating the biosynthesis and accumulation of secondary metabolites including flavonoids and terpenoids in C. camphora. Conclusion A total of 12 MYC family members have been identified from the genome of C. camphora. Among them, CcMYC1 and CcMYC8 are highly expressed in the D-borneol chemotype and citral chemotype, while CcMYC11 and CcMYC12 exhibit high expressions in the linalool chemotype. These genes may contribute significantly to the biosynthesis and accumulation of essential oil main components, terpenoids and other secondary metabolites in different chemotypes of C. camphora.

Key words: Cinnamomum camphora, MYC transcription factor, secondary metabolism, bioinformatics analysis, genome-wide identification

XIN Qing, ZHENG Yong-jie, LI Yu-hua, TU Bai-lian, LIU Xin-liang, ZHANG Yue-ting, WU Yan-fang. Genome-wide Identification and Expression Analysis of MYC Transcription Factors in Cinnamomum camphora[J]. Biotechnology Bulletin, 2026, 42(7): 214-225.

Figures/Tables 11

Table 1 Secondary structure of MYC gene family proteins in licorice

基因名称 Gene name	α-螺旋 Alpha helix （%）	β-转角 Beta turn （%）	扩展链 Extended strand （%）	无规则卷曲 Random coil （%）
CcMYC1	197（20.10）	2（0.30）	41（6.06）	437（64.55）
CcMYC2	186（26.42）	9（1.28）	42（5.97）	467（66.34）
CcMYC3	169（32.63）	1（1.93）	52（10.04）	287（55.41）
CcMYC4	191（28.81）	1（1.96）	43（6.49）	416（62.75）
CcMYC5	182（28.53）	6（0.94）	44（6.90）	406（63.64）
CcMYC6	192（30.48）	2（0.32）	46（7.30）	390（61.90）
CcMYC7	151（26.73）	2（0.35）	37（6.55）	375（66.37）
CcMYC8	146（30.61）	8（1.68）	46（9.64）	277（58.07）
CcMYC9	180（29.70）	4（0.66）	49（8.09）	373（61.55）
CcMYC10	206（30.61）	7（1.04）	57（8.47）	403（59.88）
CcMYC11	233（32.41）	9（1.25）	51（7.09）	426（59.25）
CcMYC12	217（33.28）	7（1.07）	41（6.29）	387（59.36）

Fig. 1 Phylogenetic analysis of the MYCtranscription factor in C. camphora, A. thaliana, and P. trichocarpa

Fig. 2 Tertiary structure prediction of licorice MYC protein

Fig. 3 Chromosomal localization analysis of MYC family members in C. camphora

Fig. 4 Collinearity analysis of MYC gene family in C. camphora

Fig. 5 Collinearity analysis of MYC gene family among C. camphora, A. thaliana and O. sativa

Fig. 6 Conserved motifs, conserved domains, and gene structure analysis of MYC genes family in C. camphora

Fig.7 Prediction of cis-elements of the MYC gene family promoter in C. camphora

Fig. 8 Protein interaction network of orthologous MYC proteins in A. thaliana and C. camphora

Fig. 9 Expressions of the MYC gene in six chemotypes of C. camphoraDifferent lowercase letters denote statistically significant differences (P<0.05)

Fig. 10 Subcellular localization of CcMYC12

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