Root hair morphology and mycorrhizal colonisation of pasture species in response to phosphorus and nitrogen nutrition

2010 ◽  
Vol 61 (2) ◽  
pp. 122 ◽  
Author(s):  
J. O. Hill ◽  
R. J. Simpson ◽  
M. H. Ryan ◽  
D. F. Chapman
Keyword(s):  
Plant Species ◽  
Root Hair ◽  
Mycorrhizal Fungi ◽  
Nitrogen Nutrition ◽  
Root Hairs ◽  
P Availability ◽  
Root Colonisation ◽  
P Deficiency ◽  
Hair Morphology ◽  
Mycorrhizal Colonisation

Root hairs and arbuscular mycorrhizal fungi (AMF) increase the absorptive surface area of a root and the volume of soil explored and as such are important for nutrient acquisition in infertile soil. Root hair morphology and colonisation by AMF were compared for 10 temperate pasture species, and responses to N and P deficiency characterised. Vulpia spp., Holcus lanatus, and Lolium rigidum had the longest root hairs (range 1.02–2.36 mm) while Trifolium subterraneum had the shortest (~0.27 mm). In contrast, T. subterraneum had a much higher density of root hairs than any of the other species. In response to P deficiency, the length and density of root hairs generally increased; in response to N deficiency, both increases and decreases in the length and density of root hairs were observed. The annual dicotyledons T. subterraneum and Arctotheca calendula had much higher mycorrhizal colonisation on roots grown at low P availability than the grasses. Root colonisation decreased with increasing P availability in all species. A yield advantage from mycorrhizal colonisation was demonstrated only for T. subterraneum when P was deficient. The potential root cylinder volume of each species was calculated as an index of the ability of the species to explore soil. Although all plant species were colonised by AMF, a positive linear relationship was observed between relative P uptake rate from the soil and the rate at which potential root cylinder volumes were developed by most species. Development of potential root cylinder volume also largely explained the critical external P requirements of most species. No such relationships were observed for N. It was concluded that knowledge of root length and the length of root hairs grown in nutrient-poor conditions may be used to predict the potential of many plant species to acquire P, and also their critical external P requirement for maximum growth. However, the study also highlighted some exceptional species.

scholarly journals The effects of soil phosphorus and zinc availability on plant responses to mycorrhizal fungi: a physiological and molecular assessment

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Thi Diem Nguyen ◽  
Timothy R. Cavagnaro ◽  
Stephanie J. Watts-Williams
Keyword(s):  
Mycorrhizal Fungi ◽  
Plant Biomass ◽  
Zn Deficiency ◽  
P Availability ◽  
P Deficiency ◽  
Soil P ◽  
Positive Effects ◽  
Mycorrhizal Colonisation ◽  
Mycorrhizal Plants ◽  
Soil Zn

Abstract The positive effects of arbuscular mycorrhizal fungi (AMF) have been demonstrated for plant biomass, and zinc (Zn) and phosphorus (P) uptake, under soil nutrient deficiency. Additionally, a number of Zn and P transporter genes are affected by mycorrhizal colonisation or implicated in the mycorrhizal pathway of uptake. However, a comprehensive study of plant physiology and gene expression simultaneously, remains to be undertaken. Medicago truncatula was grown at different soil P and Zn availabilities, with or without inoculation of Rhizophagus irregularis. Measures of biomass, shoot elemental concentrations, mycorrhizal colonisation, and expression of Zn transporter (ZIP) and phosphate transporter (PT) genes in the roots, were taken. Mycorrhizal plants had a greater tolerance of both P and Zn soil deficiency; there was also evidence of AMF protecting plants against excessive Zn accumulation at high soil Zn. The expression of all PT genes was interactive with both P availability and mycorrhizal colonisation. MtZIP5 expression was induced both by AMF and soil Zn deficiency, while MtZIP2 was down-regulated in mycorrhizal plants, and up-regulated with increasing soil Zn concentration. These findings provide the first comprehensive physiological and molecular picture of plant-mycorrhizal fungal symbiosis with regard to soil P and Zn availability. Mycorrhizal fungi conferred tolerance to soil Zn and P deficiency and this could be linked to the induction of the ZIP transporter gene MtZIP5, and the PT gene MtPT4.

scholarly journals Contribution of Arbuscular Mycorrhizal Fungi, Phosphate–Solubilizing Bacteria, and Silicon to P Uptake by Plant

2021 ◽  
Vol 12 ◽  
Author(s):  
Hassan Etesami ◽  
Byoung Ryong Jeong ◽  
Bernard R. Glick
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Crop Production ◽  
Current Knowledge ◽  
Arbuscular Mycorrhizal ◽  
P Availability ◽  
Phosphate Solubilizing Bacteria ◽  
P Deficiency ◽  
Phosphate Solubilizing ◽  
P Fertilizers

Phosphorus (P) availability is usually low in soils around the globe. Most soils have a deficiency of available P; if they are not fertilized, they will not be able to satisfy the P requirement of plants. P fertilization is generally recommended to manage soil P deficiency; however, the low efficacy of P fertilizers in acidic and in calcareous soils restricts P availability. Moreover, the overuse of P fertilizers is a cause of significant environmental concerns. However, the use of arbuscular mycorrhizal fungi (AMF), phosphate–solubilizing bacteria (PSB), and the addition of silicon (Si) are effective and economical ways to improve the availability and efficacy of P. In this review the contributions of Si, PSB, and AMF in improving the P availability is discussed. Based on what is known about them, the combined strategy of using Si along with AMF and PSB may be highly useful in improving the P availability and as a result, its uptake by plants compared to using either of them alone. A better understanding how the two microorganism groups and Si interact is crucial to preserving soil fertility and improving the economic and environmental sustainability of crop production in P deficient soils. This review summarizes and discusses the current knowledge concerning the interactions among AMF, PSB, and Si in enhancing P availability and its uptake by plants in sustainable agriculture.

Plant mechanisms to optimise access to soil phosphorus

2009 ◽  
Vol 60 (2) ◽  
pp. 124 ◽  
Author(s):  
Alan E. Richardson ◽  
Peter J. Hocking ◽  
Richard J. Simpson ◽  
Timothy S. George
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Specific Root Length ◽  
Soluble Form ◽  
P Availability ◽  
Agricultural Systems ◽  
Root Characteristics ◽  
P Deficiency ◽  
Soil P ◽  
Total P

Phosphorus (P) is an important nutrient required for plant growth and its management in soil is critical to ensure sustainable and profitable agriculture that has minimal impact on the environment. Although soils may contain a large amount of total P, only a small proportion is immediately available to plants. Australian soils often have low availability of P for plant growth and P-based fertilisers are, therefore, commonly used to correct P deficiency and to maintain productivity. For many soils, the sustained use of P fertiliser has resulted in an accumulation of total P, a proportion of which is in forms that are poorly available to most plants. The efficiency with which different P fertilisers are used in agricultural systems depends on their capacity to supply P in a soluble form that is available for plant uptake (i.e. as orthophosphate anions). In addition to fertiliser source, the availability of P in soil is influenced to a large extent by physico-chemical and biological properties of the soil. Plant access to soil P is further affected by root characteristics (e.g. rate of growth, specific root length, and density and length of root hairs) and biochemical processes that occur at the soil–root interface. The ability of roots to effectively explore soil, the release of exudates (e.g. organic anions and phosphatases) from roots that influence soil P availability, and the association of roots with soil microorganisms such as mycorrhizal fungi are particularly important. These processes occur as a natural response of plants to P deficiency and, through better understanding, may provide opportunities for improving plant access to soil and fertiliser P in conventional and organic agricultural systems.

scholarly journals Carbon investment into mobilization of mineral and organic phosphorus by arbuscular mycorrhiza

2020 ◽  
Vol 57 (1) ◽  
pp. 47-64
Author(s):  
Alberto Andrino ◽  
Georg Guggenberger ◽  
Leopold Sauheitl ◽  
Stefan Burkart ◽  
Jens Boy
Keyword(s):  
Fatty Acid ◽  
Arbuscular Mycorrhiza ◽  
Mycorrhizal Fungi ◽  
Organic Phosphorus ◽  
Phospholipid Fatty Acid ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
P Availability ◽  
Organic C ◽  
P Deficiency

AbstractTo overcome phosphorus (P) deficiency, about 80% of plant species establish symbiosis with arbuscular mycorrhizal fungi (AMF), which in return constitute a major sink of photosynthates. Information on whether plant carbon (C) allocation towards AMF increases with declining availability of the P source is limited. We offered orthophosphate (OP), apatite (AP), or phytic acid (PA) as the only P source available to arbuscular mycorrhiza (AM) (Solanum lycopersicum x Rhizophagus irregularis) in a mesocosm experiment, where the fungi had exclusive access to each P source. After exposure, we determined P contents in the plant, related these to the overall C budget of the system, including the organic C (OC) contents, the respired CO2, the phospholipid fatty acid (PLFA) 16:1ω5c (extraradical mycelium), and the neutral fatty acid (NLFA) 16:1ω5c (energy storage) at the fungal compartment. Arbuscular mycorrhizal (AM) plants incorporated P derived from the three P sources through the mycorrhizal pathway, but did this with differing C-P trading costs. The mobilization of PA and AP by the AM plant entailed larger mycelium infrastructure and significantly larger respiratory losses of CO2, in comparison with the utilization of the readily soluble OP. Our study thus suggests that AM plants invest larger C amounts into their fungal partners at lower P availability. This larger C flux to the AM fungi might also lead to larger soil organic C contents, in the course of forming larger AM biomass under P-limiting conditions.

The utility of phenotypic plasticity of root hair length for phosphorus acquisition

2010 ◽  
Vol 37 (4) ◽  
pp. 313 ◽  
Author(s):  
Jinming Zhu ◽  
Chaochun Zhang ◽  
Jonathan P. Lynch
Keyword(s):  
Phenotypic Plasticity ◽  
Root Hair ◽  
Root Respiration ◽  
Root Hairs ◽  
Controlled Environment ◽  
P Availability ◽  
Hair Length ◽  
Phosphorus Acquisition ◽  
Root Hair Length ◽  
Low Phosphorus

Root hairs are subcellular protrusions from the root epidermis that are important for the acquisition of immobile nutrients such as phosphorus (P). Genetic variation exists for both root hair length and the plasticity of root hair length in response to P availability, where plasticity manifests as increased root hair length in response to low P availability. Although it is known that long root hairs assist P acquisition, the utility of phenotypic plasticity for this trait is not known. To assess the utility of root hair plasticity for adaptation to low phosphorus availability, we evaluated six recombinant inbred lines of maize (Zea mays L.) with varying root hair lengths and root hair plasticity in a controlled environment and in the field. Genotypes with long root hairs under low P availability had significantly greater plant growth, P uptake, specific P absorption rates and lower metabolic cost-benefit ratios than short-haired genotypes. Root hair length had no direct effect on root respiration. In the controlled environment, plastic genotypes had greater biomass allocation to roots, greater reduction in specific root respiration and greater final biomass accumulation at low phosphorus availability than constitutively long-haired genotypes. In the field study, the growth of plastic and long-haired genotypes were comparable under low P, but both were superior to short-haired genotypes. We propose that root hair plasticity is a component of a broader suite of traits, including plasticity in root respiration, that permit greater root growth and phosphorus acquisition in low P soils.

Direct and residual effect of biochar application on mycorrhizal root colonisation, growth and nutrition of wheat

Soil Research ◽  
2010 ◽  
Vol 48 (7) ◽  
pp. 546 ◽  
Author(s):  
Zakaria M. Solaiman ◽  
Paul Blackwell ◽  
Lynette K. Abbott ◽  
Paul Storer
Keyword(s):  
Drought Stress ◽  
Mycorrhizal Fungi ◽  
Early Stage ◽  
Wheat Yield ◽  
Phosphorus Uptake ◽  
Residual Effect ◽  
Wheat Roots ◽  
Root Colonisation ◽  
Mineral Fertiliser ◽  
Mycorrhizal Colonisation

The influence of biochar (biomass-derived black carbon) on crop growth and nutrient uptake varies based on the rate of biochar applied with fertilisers. We investigated the effect of deep-banded oil mallee biochar at different rates (0, 1.5, 3.0, and 6 t/ha) with 2 types of fertiliser (non-inoculated MultiMAPS® at 30 or 55 kg/ha; inoculated Western Mineral Fertiliser at 100 kg/ha) on wheat growth at a farmer’s field in a low rainfall area of Western Australia. Wheat yield increased significantly when biochar was applied with inoculated fertiliser and 30 kg/ha non-inoculated fertiliser. Mycorrhizal colonisation in wheat roots increased significantly with biochar application with inoculated mineral fertiliser. Mycorrhizal hyphae may have improved water supply to reduce drought stress in these treatments by extending crop exploration of water from the wide inter-rows. Grain yield increases were due to better grain survival and grain fill with reduced drought stress. Early stage phosphorus uptake was not improved by mycorrhizal colonisation—phosphorus supply from the soil and applied fertiliser was already adequate. The residual effect of biochar and mineral fertilisers was assessed using a mycorrhizal bioassay for soil collected from the field trial 2 years after application of biochar. Biochar and both fertilisers increased mycorrhizal colonisation in clover bioassay plants. Deep-banded biochar provided suitable conditions for mycorrhizal fungi to colonise plant roots.

scholarly journals Role of Ascorbate in the Regulation of the Arabidopsis thaliana Root Growth by Phosphate Availability

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Jarosław Tyburski ◽  
Kamila Dunajska-Ordak ◽  
Monika Skorupa ◽  
Andrzej Tretyn
Keyword(s):  
Root Growth ◽  
Lateral Root ◽  
Root Elongation ◽  
Lateral Roots ◽  
Primary Root ◽  
Root Hairs ◽  
P Availability ◽  
Root Tips ◽  
P Deficiency ◽  
Phosphate Availability

Arabidopsis root system responds to phosphorus (P) deficiency by decreasing primary root elongation and developing abundant lateral roots. Feeding plants with ascorbic acid (ASC) stimulated primary root elongation in seedlings grown under limiting P concentration. However, at high P, ASC inhibited root growth. Seedlings of ascorbate-deficient mutant (vtc1) formed short roots irrespective of P availability. P-starved plants accumulated less ascorbate in primary root tips than those grown under high P. ASC-treatment stimulated cell divisions in root tips of seedlings grown at low P. At high P concentrations ASC decreased the number of mitotic cells in the root tips. The lateral root density in seedlings grown under P deficiency was decreased by ASC treatments. At high P, this parameter was not affected by ASC-supplementation. vtc1 mutant exhibited increased lateral root formation on either, P-deficient or P-sufficient medium. Irrespective of P availability, high ASC concentrations reduced density and growth of root hairs. These results suggest that ascorbate may participate in the regulation of primary root elongation at different phosphate availability via its effect on mitotic activity in the root tips.

scholarly journals COMPARATIVE CARBON BALANCE OF MYCORRHIZAL AND NONMYCORRHIZAL PEPPER PLANT

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 438c-438
Author(s):  
Fred T. Davies ◽  
Randal S. Stahl ◽  
Sharon A. Duray
Keyword(s):  
Mycorrhizal Fungi ◽  
Carbon Balance ◽  
Growth Efficiency ◽  
Crop Productivity ◽  
Pepper Plant ◽  
P Availability ◽  
Maintenance Respiration ◽  
P Deficiency ◽  
Soil P ◽  
Time Dynamics

Symbiotic mycorrhizal fungi increase the P uptake of agronomic, horticultural, and forestry crops. Little is known about the real-time dynamics of carbon balance (net gain of biomass resulting from photosynthesis less the respiratory costs) of plants colonized with mycorrhizae. Our objective was to determine the carbon balance of endomycorrhizal (VAM) chile pepper `San Luis' (Capsicum annuum L.) as a model system for predicting plant response to limited P availability under elevated CO2. The increase in atmospheric CO2 is expected to result in increased plant productivity and greater demand for soil P, however, the lack of available soil P may become the most important nutritional problem limiting crop productivity. Under current conditions, the limitation of soil-P availability is an enormous problem that affects 25% of the world's arable lands. We are quantifying the carbon costs paid by the mycorrhizal plant under varying levels of P deficiency over the life cycle of the plant. Preliminary results from this study under ambient CO2 conditions indicate that there is a lower maintenance respiration and higher growth efficiency with mycorrhizal pepper plants under low soil-P conditions.

Effects induced by living mulch on rhizosphere interactions in organic artichoke: The cultivar's adaptive strategy

2016 ◽  
Vol 32 (3) ◽  
pp. 214-223 ◽  
Author(s):  
A. Trinchera ◽  
E. Testani ◽  
C. Ciaccia ◽  
G. Campanelli ◽  
F. Leteo ◽  
...  
Keyword(s):  
Plant Species ◽  
Mycorrhizal Fungi ◽  
Structural Changes ◽  
Plant Root ◽  
Root Hairs ◽  
Adaptive Strategy ◽  
P Uptake ◽  
Available Phosphorus ◽  
Living Mulch ◽  
Rhizosphere Interactions

AbstractThe plant root apparatus and the surrounding micro-environment is strongly influenced by specific abiotic and biotic conditions which occur in the plant rhizosphere system. The hypothesis of the reported research was that, in an organically managed horticultural system, the use of living mulch (LM) promotes the arbuscular mycorrhizal fungi (AMF) colonization among neighboring roots, because of the coexistence of different plants roots in confined soil spaces. This effect determines nutrient uptake optimization, although roots belong to different plant species. In the reported 2-yr field experiment (2012–2013), two Italian artichoke cultivars [Cynara cardunculusL. var.scolymus(L.),Jesinocv. andMazzaferratacv.] were intercropped with a LM mixture of plant species and compared with a no LM control. Every year, the effect of LM on artichoke root morphology and AMF colonization was evaluated by scanning electron microscopy, in order to assess abiotic and biotic rhizosphere interactions, as affected by artichoke cultivars. Also the artichoke yield, the soil available phosphorus (P) and rhizosphere P were determined. Results showed that the LM did not reduce yield of both the artichoke cultivars, when compared with the no LM ones. Furthermore, LM has: (i) induced structural changes in artichoke roots by proliferation of root hairs resulting in an increase of effective absorbing surface; (ii) promoted the rhizosphere mycorrhizal infection which improved P uptake. The modified rhizosphere interactions were found to be cultivar-dependent, being recorded only inJesinoartichoke.

scholarly journals Arbuscular mycorrhizal colonization outcompetes root hairs in maize under low phosphorus availability

2020 ◽  
Vol 127 (1) ◽  
pp. 155-166
Author(s):  
Xiaomin Ma ◽  
Xuelian Li ◽  
Uwe Ludewig
Keyword(s):  
Gene Expression ◽  
Plant Growth ◽  
Root Hair ◽  
Root Hairs ◽  
Arbuscular Mycorrhizal ◽  
Transporter Gene ◽  
Hair Length ◽  
Wild Type ◽  
Mycorrhizal Dependency ◽  
P Deficiency

Abstract Background and Aims An increase in root hair length and density and the development of arbuscular mycorrhiza symbiosis are two alternative strategies of most plants to increase the root–soil surface area under phosphorus (P) deficiency. Across many plant species, root hair length and mycorrhization density are inversely correlated. Root architecture, rooting density and physiology also differ between species. This study aims to understand the relationship among root hairs, arbuscular mycorrhizal fungi (AMF) colonization, plant growth, P acquisition and mycorrhizal-specific Pi transporter gene expression in maize. Methods Using nearly isogenic maize lines, the B73 wild type and the rth3 root hairless mutant, we quantified the effect of root hairs and AMF infection in a calcareous soil under P deficiency through a combined analysis of morphological, physiological and molecular factors. Key Results Wild-type root hairs extended the rhizosphere for acid phosphatase activity by 0.5 mm compared with the rth3 hairless mutant, as measured by in situ zymography. Total root length of the wild type was longer than that of rth3 under P deficiency. Higher AMF colonization and mycorrhiza-induced phosphate transporter gene expression were identified in the mutant under P deficiency, but plant growth and P acquisition were similar between mutant and the wild type. The mycorrhizal dependency of maize was 33 % higher than the root hair dependency. Conclusions The results identified larger mycorrhizal dependency than root hair dependency under P deficiency in maize. Root hairs and AMF inoculation are two alternative ways to increase Pi acquisition under P deficiency, but these two strategies compete with each other.

Sign in / Sign up

Export Citation Format

Share Document