NtGCN2 is associated with multilayer cadmium tolerance in tobacco via coordinated transcriptional changes in growth, antioxidant, and detoxification pathways
Jul 2026· Physiology and Molecular Biology of Plants· Vol 32, pp. 1975 - 1992· 0 citations· 59 references
Medicine
TL;DR
The findings suggest that NtGCN2 is associated with a putative transcriptional hub that may integrate growth, metabolism, and detoxification pathways, providing candidate genes and a testable framework for future functional validation.
The 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.
Cadmium (Cd) contamination in rice systems poses a significant risk to food safety and human health, necessitating the identification of key genetic regulators and develop effective mitigation strategies. In this study, the role of the protein phosphatase 2 C gene NY1 in Cd tolerance was investigated using a CRISPR/Cas9-derived ny1 mutant in neo-tetraploid rice, and the potential of molybdenum oxide nanoparticles (MoO₃-NPs) to alleviate Cd toxicity was evaluated. Under Cd stress, loss of NY1 function significantly increased plant sensitivity, as evidenced by greater reductions in growth and photosynthetic pigments, higher Cd accumulation, and increased oxidative damage compared to the wild type. The ny1 mutant exhibited disrupted redox homeostasis, characterized by higher levels of H2O2 and malondialdehyde and reduced activities of key antioxidant enzymes. Cytological analyses revealed severe damage to root cell cellular architecture and xylem structure in ny1 under Cd exposure. Transcriptome profiling further demonstrated that NY1 regulates Cd tolerance by coordinating genes involved in metal uptake and transport, oxidative stress responses, cytoskeletal organization, and DNA replication and repair. Genes linked to Cd sequestration and detoxification were downregulated in ny1, whereas uptake-related transporters were upregulated, contributing to increased Cd accumulation. Application of MoO3-NPs partially mitigated Cd toxicity in both genotypes by reducing Cd uptake, enhancing antioxidant capacity, and improving physiological performance, although the mutant remained more sensitive than the wild type. The results indicate that NY1 is vital in enhancing Cd tolerance in tetraploid rice by regulating metal transport and redox homeostasis. They also highlight MoO₃-NPs as a promising supplementary strategy for reducing Cd accumulation in rice ecosystems. These findings provide valuable insight into the potential application of nanomaterials for mitigating Cd contamination in rice cultivation. Nevertheless, further research is required to evaluate their long-term efficacy, environmental safety, and practical applicability under field conditions.
M. Shahid, Zihan Lin, Lixia Sun et al.· Journal of Hazardous Materia...· 0 citations
Osmotic stress severely limits plant growth and agricultural productivity, primarily by disrupting cellular water balance. Although the CBL-CIPK signaling network is recognized as a central mediator of abiotic stress responses, the functions of CiCIPKs from pecan (Carya illinoinensis) in osmotic stress tolerance remain largely unclear. In this study, two osmotic stress-responsive genes, CiCIPK8 and CiCIPK11, were cloned and functionally characterized via heterologous expression in Arabidopsis. Under mannitol-induced osmotic stress, transgenic lines exhibited significantly enhanced seed germination and root elongation compared with the wild-type (WT) plants. Physiological analyses revealed that overexpression of CiCIPK8 and CiCIPK11 improved osmotic stress tolerance by increasing antioxidant enzyme activities, reducing oxidative damage, and promoting the accumulation of compatible osmolytes, including proline, soluble proteins, and soluble sugars. Transcriptomic profiling, combined with quantitative reverse transcription-polymerase chain reaction (qRT-PCR) validation, demonstrated that CiCIPK8 and CiCIPK11 coordinately regulate multiple stress-responsive pathways, including plant hormone signal transduction, mitogen-activated protein kinase (MAPK) cascades, cell wall dynamics, and metabolic regulation. In addition, yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays demonstrated that CiCIPK8 interacted with CiCBL1 and CiCBL8, whereas CiCIPK11 specifically interacted with CiCBL1, suggesting the involvement of a Ca2+-dependent CBL-CIPK signaling module. In conclusion, these findings reveal that CiCIPK8 and CiCIPK11 function as positive regulators of osmotic stress tolerance by integrating ROS scavenging, osmotic adjustment, and transcriptional reprogramming. This study provides valuable insights into stress signaling in pecan and offers candidate targets for the molecular breeding of osmotic stress-tolerant woody crops.
Ming-Wei Wang, Hong-Yu Shao, Wei-Hua Jin et al.· Plant physiology and biochem...· 0 citations
Tobacco (Nicotiana tabacum L.) is an important economic crop, from which polyphenols are crucial for regulating its growth and development as well as shaping its quality. However, few genes associated with polyphenol accumulation have been cloned from tobacco, and the molecular mechanisms underlying this process remain poorly understood. Here, we found that the tobacco transcription factor EARLY FLOWERING 3 (NtELF3), which is highly expressed in tobacco leaves, positively regulates the accumulation of chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, rutin, scopoletin, and total polyphenols in tobacco middle leaves. The metabolomic and transcriptomic analyses of middle leaves showed that a total of 177 differentially accumulated metabolites and 7409 differentially expressed genes (DEGs) were identified in ntelf3-1 mutant versus wild type, respectively. Further investigation identified that 17 DEGs were involved in phenylpropanoid metabolic and flavonoid metabolic processes. Combined analysis indicated that the phenylpropanoid and flavonoid biosynthesis pathways were also co-enriched in kyoto encyclopedia of genes and genomes enrichment analysis. Molecular biology experiment demonstrated that NtELF3 directly binds to the promoters of NtFLS-1 and NtCHIL-2 that are both associated with phenylpropanoid and flavonoid biosynthesis, and promotes their expression. Taken together, our results not only provide new theoretical support for in-depth understanding of the regulatory mechanisms underlying polyphenol accumulation in tobacco, but also offer excellent genes and germplasm resources for tobacco quality breeding.
Hai-Tao Huang, Chi Zhang, Li Xu et al.· Plant Science· 0 citations
Tobacco (Nicotiana tabacum) is a globally important commercial crop, largely due to the accumulation of nicotine, a parasympathomimetic alkaloid that contributes to its economic value and ecological fitness. While the nicotine biosynthetic pathway has been well characterized, its transcriptional regulation remains incompletely understood. MYB transcription factors are established regulators of plant secondary metabolism, particularly flavonoid biosynthesis; however, their role in nicotine biosynthesis remains unexplored. Here, we demonstrate that the Arabidopsis R2R3-MYB transcription factors AtMYB11, AtMYB12, and AtMYB111 function as positive regulators of nicotine biosynthesis in tobacco for the first time. Overexpression of these MYBs led to significant upregulation of key nicotine pathway genes, including NtPMT, NtODC, NtQPT, NtMPO, NtBBL, and NtA622, resulting in increased nicotine accumulation in both seedlings and mature plants. Notably, AtMYB111 exhibited the strongest regulatory effect. Promoter analysis revealed the presence of MYB-responsive elements in NtODC and NtQPT, and both transient expression assays and yeast one-hybrid studies confirmed direct binding of AtMYB111 to these promoters. Furthermore, exogenous application of an MYB11/12/111-derived complementary peptide (cPEP) recapitulated the induction of nicotine biosynthesis, supporting a functional role of MYB-mediated regulation. Functionally, increased nicotine and flavonoid levels in MYB-overexpressing lines conferred enhanced resistance to the fungal pathogen Alternaria solani and the herbivore Helicoverpa armigera, indicating a direct link between MYB-regulated metabolism and plant defense. Collectively, this study uncovers a previously unrecognized role of these MYB transcription factors in alkaloid biosynthesis and highlights their potential for metabolic engineering of nicotine content and stress resilience in tobacco.
A novel SbWRKY6‑SbPLAC8-17 transcriptional cascade that positively regulates Cd tolerance by facilitating Cd²⁺ efflux is elucidates, providing promising genetic targets for phytoremediation and molecular breeding of safe sorghum cultivars for Cd-contaminated fields.
Shan Cao, Jiqing Zhang, Zhengyu Guo et al.· Journal of Hazardous Materia...· 0 citations
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