Genome-level analysis of BpR2R3-MYB family genes transcribed in seedlings of Betula platyphylla and BpR2R3-MYB15 enhanced flavonoid production

Abstract

Background Flavonoids have a wide range of biological activities in plant development, stress resistance and human health, etc. R2R3-MYBs are one of the key elements in regulation of flavonoid production, but their functional importance in Betula platyphylla remains elusive. Methods The full-length transcriptome data of 30-day-old seedlings of Betula platyphylla were used to identify BpR2R3-MYB family genes, and their gene structure, chromosome distribution and syntenic relationships were predicted by bioinformatics methods. Agrobacterium-mediated transient transformation was used to verify the function of BpR2R3-pMYB15 in flavonoid production. Results 44 BpR2R3-MYB family genes expressed in seedlings of Betula platyphylla were identified and found to be unevenly distributed in 11 chromosomes. Among them, 90.90% of the BpR2R3-MYBs had introns, and only four genes had no introns. Five gene pairs with segment duplication were found, and their Ka/Ks ratios were less than 1. Thirty orthologs between Betula platyphylla and Arabidopsis thaliana and 68 orthologs between Betula platyphylla and Populus trichocarpa were detected. Five BpR2R3-MYBs were clustered with R2R3-MYB genes related to flavonoid synthesis, and BpR2R3-pMYB15 had the highest correlation coefficients between the value of gene expression and flavonoid content. BpR2R3-pMYB15 was cloned, and its transient overexpression obtained using Agrobacterium-mediated transformation positively regulated flavonoid production. Conclusion This work enriches the collection of R2R3-MYBs related to flavonoid production in seedlings of Betula platyphylla. Graphical Abstract

Characteristic analysis of BpbZIP family genes and BpbZIP26 significantly enhanced triterpenoid production in Betula platyphylla under S-nitrosothiol treatment

“…Agrobacterium tumefaciens strain LBA4404 harboring pBWA(V)HS-BpbZIP26-GLosgfp (overexpression vector) or pBWA(V)KS-BpbZIP26-GUS (RNAi vector) was used to infect 15-day-old B. platyphylla calli (soaked in 25% sucrose for 5 min) for 1h. The infection solution was reported by Liu et al (2022), and the main reagent as follows: 2 mM•L -1 of MES-KOH (pH=5.4), 10 mM•L -1 of CaCl 2 , 120 μM•L -1 of acetosyringone (AS), 2% sucrose, 270 mM•L -1 of mannitol, and 200 mg •L -1 of dithiothreitol + 0.02% Tween. The infected calli were cultured in B 5 liquid medium containing 100 μmol•L −1 of AS for 2 days in the dark at 28 °C [18].…”

Characteristic analysis of BpbZIP family genes and BpbZIP26 significantly enhanced triterpenoid production in Betula platyphylla under S-nitrosothiol treatment

“…All annotated sequences were obtained from the genome of B. platyphylla (accession code PRJNA285437) [16], and bZIP domain (PF00170) downloaded from the Pfam database was used to detect the possible bZIP protein of B. platyphylla through the HMM search program (E value < 1 × 10 −5 ). All putative proteins were subjected to conserved structural domain identification using SMART software and the NCBI-CDD database [17]. Fifty-one BpbZIP family genes were identified and numbered according to their positions on chromosomes.…”

“…The physicochemical properties, protein molecular weights (MW), and theoretical isoelectric points (pI) of the 51 identified bZIP proteins were analyzed by ExPASy-ProtParam. The subcellular localization was predicted by Plant-mPLoc [17]. The chromosome location information was analyzed using TBtools software.…”

“…PHYLOG-ENY in MEGA X software was adopted to construct a maximum-parsimony tree through 1000 bootstrap replications. The above precited results were visualized using TBtools software [17,18].…”

“…Clustal W in MEGA X software were used to align the amino acid sequences of the 51 BpbZIP proteins and 78 A. thaliana bZIP proteins, and PHYLOGENY in MEGA X software was used to draw a neighbor-joining tree (1000 bootstrap replications) [4,17]. The phylogenetic tree was modified using the online software EvolView.…”