Proc Natl Acad Sci U S A
September 2024
Root exudates are known signaling agents that influence legume root nodulation, but the molecular mechanisms for nonflavonoid molecules remain largely unexplored. The number of soybean root nodules during the initial growth phase shows substantial discrepancies at distinct developmental junctures. Using a combination of metabolomics analyses on root exudates and nodulation experiments, we identify a pivotal role for certain root exudates during the rapid growth phase in promoting nodulation.
View Article and Find Full Text PDFThe crucial role of TIR1-receptor-mediated gene transcription regulation in auxin signaling has long been established. In recent years, the significant role of protein phosphorylation modifications in auxin signal transduction has gradually emerged. To further elucidate the significant role of protein phosphorylation modifications in auxin signaling, a phosphoproteomic analysis in conjunction with auxin treatment has identified an auxin activated Mitogen-activated Protein Kinase Kinase Kinase (MAPKKK) VH1-INTERACTING Kinase (VIK), which plays an important role in auxin-induced lateral root (LR) development.
View Article and Find Full Text PDFAUXIN RESPONSE FACTOR 7 (ARF7)-mediated auxin signaling plays a key role in lateral root (LR) development by regulating downstream LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factor genes, including LBD16, LBD18, and LBD29. LBD proteins are believed to regulate the transcription of downstream genes as homodimers or heterodimers. However, whether LBD29 forms dimers with other proteins to regulate LR development remains unknown.
View Article and Find Full Text PDFIn plant roots, the identity of the stem cell niche (SCN) is maintained by an auxin gradient with its maximum in the quiescent center (QC). Optimal levels of auxin signaling are essential for root SCN identity, but the regulatory mechanisms that control this pathway in root are largely unknown. Here, we find that the zinc finger transcription factor sensitive to proton rhizotoxicity 1 (STOP1) regulates root SCN identity by negative feedback of auxin signaling in root tips.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
May 2023
The plant hormone auxin plays a key role to maintain root stem cell identity which is essential for root development. However, the molecular mechanism by which auxin regulates root distal stem cell (DSC) identity is not well understood. In this study, we revealed that the cell cycle factor DPa is a vital regulator in the maintenance of root DSC identity through multiple auxin signaling cascades.
View Article and Find Full Text PDFObjective: MicroRNAs (miRNAs) are key regulators in osteoarthritis (OA). While the role of miR-149 in OA has not been fully understood yet. This study investigated the mechanism in which miR-149 inhibited vascular cell adhesion molecule 1 (VCAM-1) via depressing PI3K/AKT pathway, thereby alleviating OA.
View Article and Find Full Text PDFPlant growth promoting rhizobacteria (PGPR) refer to bacteria that colonize the rhizosphere and contribute to plant growth or stress tolerance. To further understand the molecular mechanism by which PGPR exhibit symbiosis with plants, we performed a high-throughput single colony screening from the rhizosphere, and uncovered a bacterium (named promoting lateral root, PLR) that significantly promotes Arabidopsis lateral root formation. By 16S rDNA sequencing, PLR was identified as a novel sub-species of Serratia marcescens.
View Article and Find Full Text PDFThe soluble form of aluminum (Al) is a major constraint to crop production in acidic soils. The Al exclusion correlated with the Al-induced organic acid is considered as an important mechanism of Al resistance. The regulation of organic acid exudation in response to Al stress mediated by the root organic acid transporters has been extensively studied.
View Article and Find Full Text PDFCytokinins are phytohormones that regulate plant development, growth, and responses to stress. In particular, cytokinin has been reported to negatively regulate plant adaptation to high salinity; however, the molecular mechanisms that counteract cytokinin signaling and enable salt tolerance are not fully understood. Here, we provide evidence that salt stress induces the degradation of the cytokinin signaling components Arabidopsis (Arabidopisis thaliana) response regulator 1 (ARR1), ARR10 and ARR12.
View Article and Find Full Text PDFSensitive to proton rhizotoxicity 1 (STOP1) functions as a crucial regulator of root growth during aluminum (Al) stress. However, how this transcription factor is regulated by Al stress to affect downstream genes expression is not well understood. To explore the underlying mechanisms of the function and regulation of STOP1, we employed a yeast two hybrid screen to identify STOP1-interacting proteins.
View Article and Find Full Text PDFThe plant hormone auxin plays a critical role in root growth and development; however, the contributions or specific roles of cell-type auxin signals in root growth and development are not well understood. Here, we mapped tissue and cell types that are important for auxin-mediated root growth and development by manipulating the local response and synthesis of auxin. Repressing auxin signaling in the epidermis, cortex, endodermis, pericycle or stele strongly inhibited root growth, with the largest effect observed in the endodermis.
View Article and Find Full Text PDFKey Message: Plant growth is greatly inhibited in tightly sealed Petri dishes for lack of CO. Bacteria which co-cultured with plant can produce CO to promote plant growth in sealed systems. Bacteria produce a wide variety of volatiles, some of which can support and others can damage plant growth.
View Article and Find Full Text PDFPathogen entry into host tissues is a critical and first step in infections. In plants, the lateral roots (LRs) are a potential entry and colonization site for pathogens. Here, using a GFP-labeled pathogenic bacterium Pseudomonas syringae pv.
View Article and Find Full Text PDFObjective: This study was performed to determine the risk factors associated with intensive care unit delirium (ICUD) in patients undergoing invasive mechanical ventilation (IMV) secondary to acute exacerbation of chronic obstructive pulmonary disease (COPD).
Methods: Data involving 620 patients undergoing IMV secondary to acute exacerbation of COPD from 2009 to 2019 at the First Hospital of Hebei Medical University were retrospectively analysed. The primary endpoint was the risk factors associated with developing ICUD.
Pre-mRNA (messenger RNA) splicing participates in the regulation of numerous biological processes in plants. For example, alternative splicing shapes transcriptomic responses to abiotic and biotic stress, and controls developmental programs. However, no study has revealed a role for splicing in maintaining the root stem cell niche.
View Article and Find Full Text PDFBackground: p120 catenin (p120ctn) is an important component in the cadherin-catenin cell adhesion complex because it stabilizes cadherin-mediated intercellular junctions. Outside these junctions, p120ctn is actively involved in the regulation of small GTPases of the Rho family, in actomyosin dynamics and in transcription regulation. We and others reported that loss of p120ctn in mouse embryos results in an embryonic lethal phenotype, but the exact developmental role of p120ctn during brain formation has not been reported.
View Article and Find Full Text PDFAlthough the fates of microplastics (0.1-5 mm in size) and nanoplastics (<100 nm) in marine environments are being increasingly well studied, little is known about the behaviour of nanoplastics in terrestrial environments, especially agricultural soils. Previous studies have evaluated the consequences of nanoplastic accumulation in aquatic plants, but there is no direct evidence for the internalization of nanoplastics in terrestrial plants.
View Article and Find Full Text PDFShade avoidance syndrome (SAS) arises in densely growing plants that compete for light. In Arabidopsis thaliana, phytochrome interacting factor (PIF) proteins link the perception of shade to stem elongation via auxin production. Here, we report that PIFs inhibit the shade-induced expression of AUXIN RESPONSE FACTOR 18 (ARF18), and ARF18 represses auxin signaling.
View Article and Find Full Text PDFAluminum (Al) stress is a major limiting factor for plant growth and crop production in acid soils. At present, only a few transcription factors involved in the regulation of Al resistance have been characterized. Here, we used reversed genetic approach through phenotype analysis of overexpressors and mutants to demonstrate that AtHB7 and AtHB12, two HD-Zip I transcription factors, participate in Al resistance.
View Article and Find Full Text PDFThe development of lateral roots in Arabidopsis thaliana is strongly dependent on signaling directed by the AUXIN RESPONSE FACTOR7 (ARF7), which in turn activates LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factors (LBD16, LBD18 and LBD29). Here, the product of PRH1, a PR-1 homolog annotated previously as encoding a pathogen-responsive protein, was identified as a target of ARF7-mediated auxin signaling and also as participating in the development of lateral roots. PRH1 was shown to be strongly induced by auxin treatment, and plants lacking a functional copy of PRH1 formed fewer lateral roots.
View Article and Find Full Text PDFEnviron Sci Technol
March 2020
Although the fate of nanoplastics (<100 nm) in freshwater systems is increasingly well studied, much less is known about its potential threats to cyanobacterial blooms, the ultimate phenomenon of eutrophication occurrence worldwide. Previous studies have evaluated the consequences of nanoplastics increasing the membrane permeability of microbes, however, there is no direct evidence for interactions between nanoplastics and microcystin; intracellular hepatotoxins are produced by some genera of cyanobacteria. Here, we show that the amino-modified polystyrene nanoplastics (PS-NH) promote microcystin synthesis and release from , a dominant species causing cyanobacterial blooms, even without the change of coloration.
View Article and Find Full Text PDFThe phytohormone auxin controls plant growth and development via TIR1-dependent protein degradation of canonical AUX/IAA proteins, which normally repress the activity of auxin response transcription factors (ARFs). IAA33 is a non-canonical AUX/IAA protein lacking a TIR1-binding domain, and its role in auxin signaling and plant development is not well understood. Here, we show that IAA33 maintains root distal stem cell identity and negatively regulates auxin signaling by interacting with ARF10 and ARF16.
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