scholarly journals Mathematical Model and Simulation for Nutrient-Plant Interaction Analysis

Author(s):  
Byunghyun Ban

Differential equation models to understand interaction between plant and nutrient solution are presented. The root cells selectively emit H+ ions with active transport consuming ATPs to establish electrical gradient along the cell membrane. It establishes electrical field with Nernst potential to make positively charged ions outside the cell membrane flow into the root cell. Anion influx is also modulated by H+ ion concentration because plant root cell absorbs negatively charged particles with symport. If an anion collides with H+ cell to make net charge as neutral, at symport channel, it can flow through. In this paper, mathematical models for cation and anion absorption are introduced. Cation absorption model was induced from Ohm's law combined with Goldman's equation. Anion absorption model is similar to chemical reaction rate model. Both models have physiological terms influenced by gene expression pattern, species or phenotypes. Cation model also includes terms for ion's kinetic and electrical properties, growth of plant and interaction between the root and the surroundings. Simulation for 20 different sets of coefficients showed that the physiology-related coefficient has important role on nutrition absorption tendencies of plants.

2021 ◽  
Author(s):  
Yunpeng Liu ◽  
Xia Shu ◽  
Lin Chen ◽  
Huihui Zhang ◽  
Haichao Feng ◽  
...  

Niche colonization is the key for bacterial adaptation to the environment, and competition for iron largely determines root colonization by rhizosphere microbes. Pathogenic and beneficial symbiotic bacteria use various unique secretion systems to support plant colonization or acquire limited resources from the environment. However, ubiquitous nonsymbiotic beneficial rhizobacteria have never been reported to use a unique secretion system to facilitate colonization. Here, we show that the type VII secretion system (T7SS) of the beneficial rhizobacterium Bacillus velezensis SQR9 contributes to root colonization. Knocking out T7SS and the major secreted protein YukE in SQR9 caused a significant decrease in root colonization. Moreover, the T7SS and YukE caused iron loss in plant roots in the early stage after inoculation, which contributed to root colonization by SQR9. Interestingly, purified YukE, but not inactivated YukE, could change the permeability of root cells. We speculated that secreted YukE might be directly inserted into the root cell membrane to cause iron leakage, indicating that the bacterial protein and root cell membrane interact directly. Moreover, a bacterial siderophore and the T7SS may be coordinately involved in iron acquisition by B. velezensis SQR9 for efficient root colonization. We showed that the beneficial rhizobacterium B. velezensis SQR9 could acquire iron from roots via the T7SS for rapid colonization. These findings provide the first insight into the function of the unique secretion system in nonsymbiotic beneficial rhizobacteria and reveal a novel mutualism in which plants and bacteria might share iron in a sequential manner.


Author(s):  
Tania Ho-Plágaro ◽  
Raúl Huertas ◽  
María I Tamayo-Navarrete ◽  
Elison Blancaflor ◽  
Nuria Gavara ◽  
...  

Abstract The formation of arbuscular mycorrhizal (AM) symbiosis requires plant root host cells to undergo major structural and functional reprogramming in order to house the highly branched AM fungal structure for the reciprocal exchange of nutrients. These morphological modifications are associated with cytoskeleton remodelling. However, molecular bases and the role of microtubules (MTs) and actin filament dynamics during AM formation are largely unknown. In this study, the tomato tsb gene, belonging to a Solanaceae group of genes encoding MT-associated proteins for pollen development, was found to be highly expressed in root cells containing arbuscules. At earlier stages of mycorrhizal development, tsb overexpression enhanced the formation of highly developed and transcriptionally active arbuscules, while tsb silencing hampers the formation of mature arbuscules and represses arbuscule functionality. However, at later stages of mycorrhizal colonization, tsb OE roots accumulate fully developed transcriptionally inactive arbuscules, suggesting that the collapse and turnover of arbuscules might be impaired by TSB accumulation. Imaging analysis of the MT cytoskeleton in cortex root cells overexpressing tsb revealed that TSB is involved in MT-bundling. Taken together, our results provide unprecedented insights into the role of novel MT-associated protein in MT rearrangements throughout the different stages of the arbuscule life cycle.


2002 ◽  
Vol 51 (1-2) ◽  
pp. 123-128 ◽  
Author(s):  
András Halbritter ◽  
T. Mogyoróssy

To analyze the rhizosphere bacterial communities in wetlands, the total lipid content was extracted from a peat soil and 4 abundant wetland plant roots ( Typha angustifolia L., Salix cinerea L., Carex pseudocyperus L., Thelypteris palustris Salisb.). The separated phospholipid fraction was further fractionated and deriva­tized prior to gas chromatography-mass spectrometry (GC-MS) measurement. In the evaluation only the bacteria-specific fatty acids were used in order to neglect fatty acid information derived from plant root cells. Based on these analyses, a high level bacterial concentration was demonstrated in the rhizosphere, and the relative occurrence of aerobe and anaerobe, Gram positive and negative bacteria, methanotrophs, sulphate reducers and Actinobacteria was determined. Through the PLFA analysis the study of bacteria regardless of culturability was possible.


1922 ◽  
Vol 4 (4) ◽  
pp. 403-409 ◽  
Author(s):  
Calvin B. Coulter

1. The addition of blood serum displaces the optimum for agglutination of red blood cells in a salt-free medium to the reaction characteristic of flocculation of the serum euglobulin. 2. This effect is not due merely to a mechanical entanglement of the cells by the precipitating euglobulin, since at reactions at which the latter is soluble it protects the cells from the agglutination which occurs in its absence. 3. A combination of some sort appears therefore to take place between sheep cells and sheep, rabbit, and guinea pig serum euglobulin, and involves a condensation of the serum protein upon the surface of the red cell. 4. At the optimal point for agglutination of persensitized cells both mid- and end-piece of complement combine with the cells. 5. Agglutination is closely related to an optimal H ion concentration in the suspending fluid, and probably of the cell membrane, and not to a definite reaction in the interior of the cell.


1987 ◽  
Vol 33 (2) ◽  
pp. 161-175 ◽  
Author(s):  
Tadao Wagatsuma ◽  
Minoru Kaneko ◽  
Yasuhiro Hayasaka

1971 ◽  
Vol 32 (1) ◽  
pp. 1-23 ◽  
Author(s):  
John R. Buysman ◽  
Frank T. Koide

2004 ◽  
Vol 31 (4) ◽  
pp. 391 ◽  
Author(s):  
Nick Gould ◽  
Michael R. Thorpe ◽  
Peter E. H. Minchin ◽  
Jeremy Pritchard ◽  
Philip J. White

This work relates solute import to elongating root cells in barley to the water relations of the symplastic pathway under conditions of varied plant K+ status. K+ is a major constituent of phloem sieve element (SE) sap, and as an osmoticum, it is believed to have a role in maintaining SE hydrostatic pressure and thus sap flow from source to sink tissue. The hypothesis that the solute import to elongating root cells is linked to pressure driven flow from the sieve tube is examined.Plants were grown in solutions containing either 0.05 mM (low K) or 2.05 mM (high K) K+ concentration. Solute import to the root elongation zone was estimated from biomass accumulation over time accounting for respiration and root elongation rate. SE sap K+ concentration was measured using X-ray microanalyses and osmotic pressure by picolitre osmometry. SE hydrostatic pressure was measured directly with a pressure probe glued onto an excised aphid stylet. Elongating root cell hydrostatic pressure was measured using a cell pressure probe.The low-K plants had lower SE K+ concentration and SE hydrostatic pressure compared to the high-K plants, but the elongating root cell hydrostatic pressure was similar in both treatments, thus the pressure difference between the SE and elongating root cells was less in the low-K plants compared to the high-K plants.The solute import rate to elongating root cells was lower in the low K plants and the reduction could be accounted for as a pressure driven solute flux, with a reduction both in the pressure difference between root sieve elements and elongating cells, and in the sap concentration.


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