The polar transport of the plant hormone auxin has been the subject of many studies, several involving mathematical modelling. Unfortunately, most of these models have not been experimentally verified. Here we present experimental measurements of long-distance polar auxin transport (PAT) in segments of inflorescence stems of Arabidopsis thaliana together with a descriptive mathematical model that was developed from these data. It is based on a general advection-diffusion equation for auxin density, as suggested by the chemiosmotic theory, but is extended to incorporate both immobilization of auxin and exchange with the surrounding tissue of cells involved in PAT, in order to account for crucial observations. We found that development of the present model assisted effectively in the analysis of experimental observations. As an example, we discuss the analysis of a quadruple mutant for all four AUX1/LAX1-LAX3 influx carriers genes. We found a drastic change in the parameters governing the exchange of PAT channels with the surrounding tissue, whereas the velocity was still of the order of magnitude of the wild type. In addition, the steady-state flux of auxin through the PAT system of the mutant did not exhibit a saturable component, as we found for the wild type, suggesting that the import carriers are responsible for the saturable component in the wild type. In the accompanying Supplementary data available at JXB online, we describe in more detail the data-driven development of the model, review and derive predictions from a mathematical model of the chemiosmotic theory, and explore relationships between parameters in our model and processes and parameters at the cellular level.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4737066 | PMC |
http://dx.doi.org/10.1093/jxb/erv471 | DOI Listing |
Planta
January 2025
State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081, China.
AtbZIP69 overexpression in wheat significantly enhanced drought and low nitrogen tolerance by modulating ABA synthesis, antioxidant activity, nitrogen allocation, and transporter gene expression, boosting yield. In this study, we generated wheat plants with improved low nitrogen (LN) and drought tolerance by introducing AtbZIP69, a gene encoding a basic leucine zipper domain transcription factor, into the wheat cultivar Shi 4056. AtbZIP69 localized to the nucleus and activated transcription.
View Article and Find Full Text PDFJ Biomol Struct Dyn
January 2025
University of Health Sciences, Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam.
The COVID-19 pandemic posed a threat to global society. Delta and Omicron are concerning variants due to the risk of increasing human-to-human transmissibility and immune evasion. This study aims to evaluate the binding ability of these variants toward the angiotensin-converting enzyme 2 receptor and antibodies using a computational approach.
View Article and Find Full Text PDFActa Neuropathol Commun
January 2025
Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College (PUMC) and Chinese Academy of Medical Science (CAMS), Beijing, China.
Mutations in the ANXA11 gene, encoding an RNA-binding protein, have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS), but the underlying in vivo mechanisms remain unclear. This study examines the clinical features of ALS patients harboring the ANXA11 hotspot mutation p.P36R, characterized by late-onset motor neuron disease and occasional multi-system involvement.
View Article and Find Full Text PDFCell Death Dis
January 2025
Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
Doxorubicin, a representative drug of the anthracycline class, is widely used in cancer treatment. However, Doxorubicin-induced cardiotoxicity (DIC) presents a significant challenge in its clinical application. Mitochondrial dysfunction plays a central role in DIC, primarily through disrupting mitochondrial dynamics.
View Article and Find Full Text PDFVet Res
January 2025
College of Veterinary Medicine, Jeonbuk National University, Iksan Campus, Iksan, 54596, Republic of Korea.
Fowl typhoid (FT) poses a significant threat to the poultry industry and can cause substantial economic losses, especially in developing regions. Caused by Salmonella Gallinarum (SG), vaccination can prevent FT. However, existing vaccines, like the SG9R strain, have limitations, including residual virulence and potential reversion of pathogenicity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!