Introduction Widespread dicamba use poses challenges of resistance and phytotoxicity. To investigate the temporal molecular response mechanisms of tobacco, this study performed a time-resolved transcriptomic analysis of tobacco seedlings exposed to dicamba. Methods Samples were collected at 6, 24, and 72 h after treatment. Results Results indicated that tobacco exhibits a putative three-phase transcriptional adaptation pattern of “perception-defense-repair”. In the early stage (6h), NtIAA genes were rapidly induced alongside activation of the glutathione system, potentially alleviating oxidative stress; at the mid-stage (24h), enhanced carotenoid synthesis and thylakoid reconstruction appeared to protect photosynthetic structures; at the late stage (72h), the transcriptional response shifted toward systemic repair through secondary metabolism, including phenylpropanoid biosynthesis. Predictive regulatory network analysis suggested that the ERF transcription factor Nitab4.5_0000015g0020 may act as a candidate hub, potentially linking auxin signaling and ribosomal protein genes. Discussion Taken together, this study provides transcriptomic evidence that the NtIAA family may serve as candidate genes in response to dicamba, offering potential genetic candidates for breeding herbicide-resistant crops.
Sesame is an important oilseed crop, and floral development is a key biological process that lays the foundation for pollination, fertilization, and seed formation, which are closely associated with final yield potential. However, the dynamic transcriptional and metabolic regulatory mechanisms during floral development remain unclear. Here, we performed an integrated transcriptomic and metabolomic analysis across five key developmental stages (T1–T5) of sesame flowers to systematically dissect the multi‑omics regulatory network. KEGG enrichment analysis revealed distinct stage‑specific metabolic characteristics: early stages (T1–T2) were enriched in primary energy metabolism (glycolysis and starch/sucrose metabolism); the middle stage (T3) showed enrichment in DNA replication and phenylpropanoid biosynthesis; and late stages (T4–T5) were associated with plant hormone signaling and α‑linolenic acid metabolism. WGCNA identified two modules correlated with development: a positive module involved in phenylpropanoid biosynthesis, and a negative module related to DNA replication and repair. Genes in the phenylpropanoid/flavonoid pathway displayed a clear sequential expression pattern, promoting flavonoid and anthocyanin accumulation. Collectively, this study provides a comprehensive multi‑omics resource and a descriptive framework for understanding transcriptional and metabolic dynamics during sesame floral development, and identifies candidate pathways and genes that may serve as targets for future functional validation and molecular breeding.
Qiyuan An, Hongsen Cheng, Huijie Sun et al.· Frontiers in Plant Science· 0 citations
This study provides a root-focused transcriptomic resource and identifies candidate regulatory genes potentially linking ABA-related responses with lignin/lignan-associated metabolism in H. pedunculosum under salt stress.
Yang Tao, Xiao Huang, Enhao Zhang et al.· Plant physiology and biochem...· 1 citation
The m⁶A demethylase ALKBH10B emerges as a crucial post-transcriptional regulator of hormonal crosstalk, photosynthetic maintenance, and mitochondrial energy metabolism to fine-tune plant stress adaptation to drought. Epitranscriptomic N⁶-methyladenosine (m⁶A) mRNA modification has emerged as an important regulatory layer of gene expression and protein synthesis in plant stress adaptation. In this study, expression profiling revealed that drought stress induces a global reprogramming of the m6A machinery in Arabidopsis thaliana, with the m6A demethylase ALKBH10B exhibiting a more pronounced time-dependent response. ALKBH10B transcription is induced by ABA, most likely via ABRE and MYB cis-elements, whereas jasmonate alleviates this activation. Moreover, ALKBH10B overexpressing plants (OX-1) accumulated wild type (WT) levels of ABA under drought stress but displayed a markedly reduced content in jasmonic acid (JA) and jasmonoyl-isoleucine (JA-Ile). They furthermore exhibit enhanced stomatal closure, improved water-use efficiency, and thus an enhanced drought tolerance. Transcriptome analysis revealed that drought stress induces fewer transcriptional changes in OX-1 plants compared to WT and the drought-sensitive alkbh10b-1 mutant. Differential expression and GO enrichment analyses highlight that photosynthesis-related processes were most affected by ALKBH10B activity, correlating with a preserved chlorophyll content and PSII efficiency in OX-1. Analysis by m⁶A-IP-qPCR showed that ALKBH10B directly demethylates specific photosynthesis-related and drought-responsive genes, while other transcripts are indirectly regulated by ALKBH10B-dependent processes. Moreover, transcripts associated with respiration were enriched in OX-1, indicating that ALKBH10B also supports mitochondrial energy metabolism during drought. Together, our results suggest that ALKBH10B enhances drought tolerance by coordinating m⁶A-dependent transcriptional and post-transcriptional regulation to maintain photosynthetic capacity and mitochondrial energy metabolism, as well as fine-tuning ABA-jasmonate crosstalk.
High-temperature stress impairs plant growth and alters secondary metabolism. Polymethoxyflavones (PMFs) are citrus-specific flavonoids with important nutritional benefits; however, their transcriptional responses to heat stress remain poorly understood. Here, five-month-old ‘Ponkan’ citrus seedlings were exposed to 40 °C for 6, 11, and 21 days. HPLC analysis showed that the accumulation of four major PMFs (sinensetin, nobiletin, tangeretin, and 5-demethylnobiletin) was significantly reduced in leaves under heat stress. RNA-seq identified 3424 differentially expressed genes shared across all three time points, which were enriched in pathways associated with microtubule cytoskeleton organization, cell cycle regulation, and glyoxylate and dicarboxylate metabolism. Further analysis of the PMF biosynthetic pathway revealed that 14 of 18 key structural genes, including CHS, CHI, FNSII, and OMT family members, were downregulated by heat treatment. In addition, several bHLH, AP2/EREBP, and MYB transcription factors, known regulators of flavonoid biosynthesis, exhibited expression patterns closely associated with PMF accumulation. RT-qPCR analysis validated the transcriptome results. Collectively, these findings suggest that heat stress suppresses PMF accumulation through coordinated repression of PMF biosynthetic genes and their potential regulators. This study provides new insights into the molecular basis of heat-responsive PMF metabolism and offers potential targets for maintaining citrus nutritional quality under elevated temperatures.
Xiaojuan Liu, Zhenkun Liao, Honglu Hu et al.· Horticulturae· 0 citations