Jul 2026· Physiologia Plantarum : An International Journal for Plant Biology· Vol 178· 0 citations· 62 references
Medicine
TL;DR
It is suggested that a complex transcriptional network governs diterpenoid biosynthesis in masson pine, offering new perspectives on the regulation of terpenoid metabolism.
Abstract
The resin of masson pine (Pinus massoniana L.) exhibits considerable economic value and primarily consists of diterpenoid resin acids. However, the upstream regulation of the key diterpene biosynthetic gene, PmLAS, remains largely unclear. In the present study, through yeast one‐hybrid screening, three PmMYB transcription factors were identified: PmMYB30, PmMYB68, and PmMYB74. Subsequent verification through dual‐luciferase assays substantiated that these transcription factors interact with the PmLAS promoter, thereby facilitating its transcriptional activation. Subcellular localization analysis indicated that all three PmMYBs are localized in the nucleus, and transcriptional activation assays in yeast further revealed that their C‐terminal regions are responsible for the transcriptional activation activity. Meanwhile, the transcript levels of three PmMYBs exhibited a significant positive correlation with resin yield in the xylem of 12‐year‐old masson pine trees. Moreover, the heterologous overexpression of these genes in tobacco resulted in a growth‐inhibiting phenotype, a marked increase in leaf glandular trichome numbers, and an elevated proportion of diterpenoids compared to wild‐type tobacco. To further elucidate the molecular regulation of the PmLAS gene by the transcription factor PmMYB30, yeast two‐hybrid library screening was performed to screen its interacting proteins. A RING‐type E3 ubiquitin ligase was identified from the screening results and designated PmRDUF1. Subsequent luciferase complementation imaging assays provided further evidence supporting the interaction between PmRDUF1 and PmMYB30. Furthermore, dual‐luciferase reporter assays demonstrated that this interaction suppresses the ability of PmMYB30 to activate the expression of PmLAS, forming a PmRDUF1‐PmMYB30‐PmLAS regulatory module. Collectively, our findings suggest that a complex transcriptional network governs diterpenoid biosynthesis in masson pine, offering new perspectives on the regulation of terpenoid metabolism.
A preliminary elucidation of the molecular mechanism by which upstream transcriptional regulation of the AmFLS gene controls flavonol biosynthesis in JHK is provided, offering a theoretical basis for further elucidating the regulatory network of flavonol metabolism in JHK and accelerating its industrial development.
Dayun Wang, Hongtao Chu, Zhong Liu et al.· Plants· 0 citations
An integrated multi-omics analysis of dwarf and normal-height red tangerine × trifoliate orange hybrid seedlings revealed a PtARF6/8-PtGH3.1 transcriptional module that regulates auxin homeostasis through IAA conjugation, providing genetic insights into GH3.1-mediated dwarfism.
Integrated transcriptomic and metabolomic characterization of knockout mutants (Stgame9) revealed extensive reprogramming of gene expression and metabolism, affecting not only SGA and sterol pathways but also a broader range of metabolic processes, with stress-related metabolic responses being attenuated in Stgame9 tubers.
Ying Liu, Irene Merino, Lizel Potgieter et al.· Plant physiology and biochem...· 0 citations
Theanine, a unique nonproteinogenic natural amino acid predominantly accumulated in tea plants (Camellia sinensis), is a key determinant of tea flavor and quality, with broad applications. Theanine synthase (CsTSI) is a key enzyme in theanine biosynthesis. However, the transcriptional regulation of CsTSI, particularly by bHLH transcription factors, remains largely unexplored. Through coexpression network screening and tissue-specific qPCR, we identified CsbHLH18 as a putative regulator of CsTSI. Yeast one-hybrid (Y1H) and dual-luciferase reporter assays confirmed the direct interaction between CsbHLH18 and the CsTSI promoter. An electrophoretic mobility shift assay (EMSA) further identified the specific binding motif of CsbHLH18 as "CAAATG". Transient overexpression and virus-induced gene silencing (VIGS) in tea plants demonstrated that CsbHLH18 positively regulates theanine biosynthesis by activating CsTSI transcription. These findings elucidate a previously uncharacterized molecular mechanism underlying theanine biosynthesis and provide theoretical insights into molecular breeding and cultivation of high-quality tea varieties.
Yu Fu, Siqing Zhu, Qianlan Liu et al.· Journal of Agricultural and...· 0 citations
Soil salinization limits the yield and quality of Dendrobium officinale. The molecular mechanisms linking methyl jasmonate (MeJA) signaling to the biosynthesis of glucomannans (GMs) under salinity remain unclear. In the WGCNA of MeJA- and salinity-treated D. officinale transcriptome, an R2R3-MYB transcription factor was identified, DoMYB41, which was highly expressed in stems and induced by both treatments. Overexpression of DoMYB41 in PLBs increased GMs and anthocyanin, enhanced the activities of antioxidant enzymes, reduced oxidative damage, and elevated relative water content, whereas CRISPR/Cas9 knockout lines showed opposite phenotypes. Transcriptomic analysis identified DoTIP1–1 as a key downstream target, and biochemical assays (dual-LUC, Y1H, EMSA) confirmed that DoMYB41 activates DoTIP1–1 transcription by directly targeting the MBS motif present in its promoter. Furthermore, DoMYB41 physically interacted with the bHLH transcription factor DoMYC2, which alone bound to and activated the promoters of both DoTIP1–1 and DoMYB41, forming a positive feedback loop. Intriguingly, DoMYB41 and DoMYC2 synergistically activated DoTIP1–1. These findings uncovered a MeJA-responsive DoMYB41-DoMYC2 cascade that iteratively activates DoTIP1–1 expression and promotes the biosynthesis of GMs, thereby enhancing salinity tolerance in D. officinale. This study also provides genetic targets for salinity tolerance in breeding programs for this horticultural orchid.
Sugarcane smut, caused by Sporisorium scitamineum, is one of the most devastating diseases of sugarcane worldwide, leading to severe yield losses and long-term agricultural impacts. Integral membrane proteins are essential components of plasma membranes, playing critical roles in molecular transport, signal transduction, pathogenesis, and defense. However, their contributions to sexual mating and pathogenicity in smut fungi remain largely unknown. In this study, we sought to characterize two novel integral membrane proteins—regulation of whip and teliospore development 1 (RWTD1) and pheromone-regulated multispanning membrane protein (PRM1)—in S. scitamineum. The RWTD1 protein, which contains four transmembrane domains, showed mating-specific upregulation and localized to discrete puncta in the cytoplasm near the cell membrane. The deletion of RWTD1 in Mat-1 haploids abolished filamentous growth after sexual mating, whereas its deletion in Mat-2 haploids resulted in reduced filamentation. Transcriptome profiling revealed that, relative to the wild type, genes encoding several integral and intrinsic membrane components were differentially expressed in RWTD1 mutants, including PRM1 and DIK6, which encode putative four- and seven-transmembrane domain proteins, respectively. Deleting PRM1 recapitulated the mating defects observed in the ΔRWTD1 mutants. While RWTD1, PRM1, and DIK6 contributed to virulence, RWTD1 also functioned in symptom development and teliospore formation. Overall, our work demonstrated that the transmembrane proteins RWTD1, PRM1, and DIK6 are important contributors to virulence and sexual mating in the sugarcane smut fungus.
Shan Lu, Shaofeng Tan, Mi Liang et al.· Phytopathology Research· 0 citations