Search

Euphorbia fauriei, a perennial plant endemic to South Korea, exhibits both morphological characteristics and intricate genetic identities akin to E. pekinensis. This study aimed to provide clarity on the taxonomic status of E. faurirei and E. pekinensis through a comprehensive chloroplast genome analysis. Additionally, we sequenced the Acalypha australis chloroplast genome as an outgroup for the construction of a phylogenetic tree with other Euphorbia species. The three chloroplast genomes, ranging from 162,834 bp to 168,832 bp, displayed typical quadripartite structures. The Euphorbia genomes contained 111 unique genes, whereas the A. australis genome contained two additional protein-coding genes (PCGs), rpl32 and rps16. Comparative analysis unveiled the loss of rpl32 and rps16 as synapomorphic characteristics in Euphorbia, whereas the loss of infA occurred across Euphorbiaceae. High collinearity and sequence similarity were observed among Euphorbia species, accompanied by significant inversion regions in the E. pekinensis chloroplast genomes from China and Japan, indicating regional genetic variability. Nucleotide substitution analysis revealed that the ndh group exhibited the highest K A /K S values (0.224), whereas the atp, psa, psb and rps groups had the lowest. Phylogenomic analysis utilizing whole genomes, PCGs, and intron and intergenic regions consistently demonstrated that E. pekinensis from South Korea clusters closely with E. fauriei. These findings challenge the current taxonomic distinction between E. pekinensis and E. fauriei in Korea, suggesting that while they exhibit distinct characteristics, E. fauriei should be considered a closely related subspecies rather than the same species as E. pekinensis. This study emphasizes the need for population studies to clarify the taxonomic relationships between E. pekinensis and E. fauriei., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Macrocyclic diterpenoid esters from Euphorbiaceae plants hold significant medicinal value owing to their structural diversity and for attributing structural uniqueness and biological efficacy. However, the responsible enzymes for the acylation of macrocyclic diterpenoids remain unknown. We identified two macrocyclic diterpenoid O-acyltransferases, ElBAHD16 and ElBAHD35, from the diterpene biosynthetic gene cluster of Euphorbia lathyris. ElBAHD16 and ElBAHD35 were characterized both in vitro (using Escherichia coli) and in vivo (using Nicotiana benthamiana and E. lathyris) and exhibited mono-acylation activities toward the hydroxy groups of their substrates, 7-hydroxylathyrol and lathyrol. ElBAHD16 showed not only regioselectivity toward the 7-OH group of 7-hydroxylathyrol but also donor promiscuity, thereby producing three different mono-acylation products. Conversely, ElBAHD35 demonstrated specific recognition for the 5-OH group of 7-hydroxylathyrol and lathyrol, thereby mediating mono-acetylation reactions with acetyl-CoA, showing donor specificity. Site-directed mutagenesis revealed that residues H154 and T363 in ElBAHD16 are critical for its catalytic activity. Notably, the Q35 residue enhanced the efficiency of ElBAHD16, while the M296, N292, and F394 residues were crucial for its donor promiscuity. These findings elucidate the last step in the biosynthesis of macrocyclic diterpenoid esters and highlight the contribution of acyltransferases to the structural diversity of diterpenoids., (© 2025 Society for Experimental Biology and John Wiley & Sons Ltd.)

The biosynthesis of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are essential for sesquiterpenes and triterpenes, respectively, is primarily governed by the mevalonate pathway, wherein farnesyl pyrophosphate synthase ( FPS ) plays a pivotal role. This study identified eight members of the FPS gene family in Euphorbia hirta , designated EhFPS1 - EhFPS8 , through bioinformatics analysis, revealing their distribution across several chromosomes and a notable tandem gene cluster. The genes exhibited strong hydrophilic properties and key functional motifs crucial for enzyme activity. An in-depth analysis of the EhFPS genes highlighted their significant involvement in isoprenoid metabolism and lipid biosynthesis, with expression patterns influenced by hormones such as jasmonic acid and salicylic acid. Tissue-specific analysis demonstrated that certain FPS genes, particularly EhFPS1 , EhFPS2 , and EhFPS7 , showed elevated expression levels in latex, suggesting their critical roles in terpenoid biosynthesis. Furthermore, subcellular localization studies have indicated that these proteins are primarily found in the cytoplasm, reinforcing their function in metabolic processes. These findings provide a foundational understanding of the FPS genes in E. hirta , including their gene structures, conserved domains, and evolutionary relationships. This study elucidates the potential roles of these genes in response to environmental factors, hormone signaling, and stress adaptation, thereby paving the way for future functional analyses aimed at exploring the regulation of terpenoid biosynthesis and enhancing stress tolerance in this species.