scholarly journals Significance of root hairs for plant performance under contrasting field conditions and water deficit

2020 ◽  
Author(s):  
M Marin ◽  
D S Feeney ◽  
L K Brown ◽  
M Naveed ◽  
S Ruiz ◽  
...  
Keyword(s):  
Stress Tolerance ◽  
Root Hair ◽  
Water Status ◽  
Root Hairs ◽  
Plant Performance ◽  
Plant Water ◽  
Optimal Conditions ◽  
Hair Length ◽  
Climate Conditions ◽  
P Accumulation

Abstract Background and Aims Previous laboratory studies have suggested selection for root hair traits in future crop breeding to improve resource use efficiency and stress tolerance. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. As such, this study aims to experimentally elucidate some of the impacts that root hairs have on plant performance on a field scale. Methods A field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield. Key Results Measurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in a less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought. Conclusions Selecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder’s dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.

Penicillium bilaii inoculation increases root-hair production in field pea

2000 ◽  
Vol 80 (4) ◽  
pp. 801-804 ◽  
Author(s):  
Robert H. Gulden ◽  
J. Kevin Vessey
Keyword(s):  
Pisum Sativum ◽  
Root Hair ◽  
Root Morphology ◽  
Shoot Growth ◽  
Root Hairs ◽  
Root Diameter ◽  
Hair Length ◽  
P Accumulation ◽  
The Mean ◽  
Hair Diameter

Under three levels of phosphorus availability, inoculation of pea plants with Penicillium bilaii in growth pouches had no effect on root length (excluding root hairs), mean root diameter, root-hair diameter, P accumulation or shoot growth. However, inoculation with P. bilaii resulted in a 22% increase in the proportion of root containing root hairs and a 33% increase in the mean root-hair length. Key words: Pea, Penicillium bilaii, Pisum sativum, phosphorus, root hairs, root morphology

The effect of root hairs under drought in open field conditions

2021 ◽  
Author(s):  
Maria Marin ◽  
Deborah S Feeney ◽  
Lawrie K Brown ◽  
Muhammad Naveed ◽  
Siul Ruiz ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Open Field ◽  
Leaf Water Potential ◽  
Root Hair ◽  
Root Hairs ◽  
Leaf Water ◽  
Plant Water ◽  
Clay Loam ◽  
Wild Type

<p>Root hairs represent an attractive target for future crop breeding, to improve resource use efficiency and stress tolerance. Most studies investigating root hairs have focused on plant tolerance to phosphorus deficiency and rhizosheath formation under controlled conditions. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. Although root hairs and rhizosphere are assumed to play a key role in regulating plant water relations, their effect on plant water uptake has been rarely investigated. As such, this study aimed to experimentally elucidate some of the impacts that root hairs have on plant performance under field conditions and water deficit. A field experiment was set up in Scotland for two consecutive years, in 2017 (a typical year) and 2018 (the driest growing season ever recorded at this site), under different soil textures (i.e., clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Measurements of root hair density, length and its correlation with rhizosheath weight highlighted trait robustness in the field under variable environmental conditions. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance. This resulted in less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot phosphorus accumulation. Specifically, minimum leaf water potential differed significantly (P = 0.021) between the wild type (-1.43 MPa) and its hairless mutant (-1.76 MPa) grown in clay loam, with the mutant exhibiting greater water stress. In agreement with leaf water potential measurements, at the peak of water stress, leaf abscisic acid concentration was significantly (P = 0.023) greater for the hairless mutant (394 ng g<sup>-1</sup>) than the wild type (250 ng g<sup>-1</sup>) grown in clay loam soil. Under water deficit conditions, in clay loam soil, shoot phosphorus accumulation in the wild type (2.49 mg P shoot<sup>-1</sup>) was over twice that in the hairless mutant (1.10 mg P shoot<sup>-1</sup>). Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought. While yield of the hairless mutant significantly (P = 0.012) decreased from 2017 to 2018 in both clay (-26%) and sandy (-33%) loam soils, no significant differences were found between years in the yield of the wild type. Therefore, selecting for beneficial root hair traits can enhance yield stability without diminishing yield potential, overcoming the breeder’s dilemma of trying to simultaneously enhance both productivity and resilience. To our knowledge, the present findings provide the first evidence of the effect of root hairs under drought in open field conditions (i.e., real agricultural system). Therefore, along with the well-recognized role for P uptake, maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.</p>

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.

scholarly journals The sensitivity of white clover root hairs to aluminium

1996 ◽  
Vol 6 ◽  
pp. 137-140
Author(s):  
D.A. Care
Keyword(s):  
White Clover ◽  
Root Hair ◽  
Root Hairs ◽  
Aluminium Tolerance ◽  
Hair Length ◽  
Pastoral Systems ◽  
Root Hair Length ◽  
Clover Root ◽  
Low Ionic Strength ◽  
Two Populations

Two populations of white clover, selected for long (L) and short (S) root hairs from the cultivar Tamar, were used to determine the root hair response curve to a range of aluminium (Al) concentrations similar to those found under field conditions. Seeds from the L and S populations were germinated and grown in low ionic strength hydroponic culture. Al was added to give final concentrations of 0, 2.5, 5, 7.5 and 10 ìM Al in solution. After 4 weeks plants were harvested and subsampled for root hair analysis. Mean root hair length, root hair number and total root hair length were recorded. Mean root hair length decreased by about 30% at 2.5 ìM Al, and by 70% at 10 ìM Al, but the most Al sensitive parameter was root hair number. Root hair numbers decreased by 70% at only 2.5 ìM Al, and at 10 ìM Al, had decreased by 99%. This pruning effect on total root hair length and number has major implications for the root hair functions of nutrient acquisition, preserving the moisture film, anchorage and nodulation. These are discussed in relation to New Zealand pastoral systems. Keywords: aluminium tolerance, nodulation, root hairs, root pulling, Trifolium repens L., white clover

scholarly journals Cyanobacteria-Derived Proline Increases Stress Tolerance in Arabidopsis thaliana Root Hairs by Suppressing Programmed Cell Death

2020 ◽  
Vol 11 ◽  
Author(s):  
Alysha Chua ◽  
Orla L. Sherwood ◽  
Laurence Fitzhenry ◽  
Carl K.-Y. Ng ◽  
Paul F. McCabe ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Stress Tolerance ◽  
Root Hair ◽  
Root Hairs ◽  
Biologically Active ◽  
Nostoc Muscorum ◽  
Sensitivity Threshold ◽  
Wild Type

Nitrogen-fixing heterocystous cyanobacteria are used as biofertilizer inoculants for stimulating plant growth but can also alleviate plant stress by exometabolite secretion. However, only a small number of studies have focused on elucidating the identity of said bioactives because of the wide array of exuded compounds. Here, we used the root hair assay (RHA) as a rapid programmed cell death (PCD) screening tool for characterizing the bioactivity of cyanobacteria Nostoc muscorum conditioned medium (CM) on Arabidopsis thaliana root hair stress tolerance. We found that heat-stressed A. thaliana pre-treated with N. muscorum CM fractions exhibited significantly lower root hair PCD levels compared to untreated seedlings. Treatment with CM increased stress tolerance by suppressing PCD in root hairs but not necrosis, indicating the bioactive compound was specifically modulating the PCD pathway and not a general stress response. Based on documented N. muscorum exometabolites, we identified the stress-responsive proline as a compound of interest and strong evidence from the ninhydrin assay and HPLC indicate that proline is present in N. muscorum CM. To establish whether proline was capable of suppressing PCD, we conducted proline supplementation experiments. Our results showed that exogenous proline had a similar effect on root hairs as N. muscorum CM treatment, with comparable PCD suppression levels and insignificant necrosis changes. To verify proline as one of the biologically active compounds in N. muscorum CM, we used three mutant A. thaliana lines with proline transporter mutations (lht1, aap1 and atprot1-1::atprot2-3::atprot3-2). Compared with the wild-type seedlings, PCD-suppression in lht1and aap1 mutants was significantly reduced when supplied with low proline (1–5 μM) levels. Similarly, pre-treatment with N. muscorum CM resulted in elevated PCD levels in all three mutant lines compared to wild-type seedlings. Our results show that plant uptake of cyanobacteria-derived proline alters their root hair PCD sensitivity threshold. This offers evidence of a novel biofertilizer mechanism for reducing stress-induced PCD levels, independent of the existing mechanisms documented in the literature.

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.

SEM and fluorescence imaging of callose deposition in root hair tips and suspension cultures of Streptanthus tortuosus

1990 ◽  
Vol 48 (3) ◽  
pp. 698-699
Author(s):  
K.S. Walters ◽  
R.D. Sjolund ◽  
K.C. Moore
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Cultured Cells ◽  
Root Hairs ◽  
Callus Cultures ◽  
Callose Deposition ◽  
Culture Cells ◽  
Wall Structures ◽  
Ultraviolet Illumination ◽  
Callose Formation

Callose, B-1,3-glucan, a component of cell walls, is associated with phloem sieve plates, plasmodesmata, and other cell wall structures that are formed in response to wounding or infection. Callose reacts with aniline blue to form a fluorescent complex that can be recognized in the light microscope with ultraviolet illumination. We have identified callose in cell wall protuberances that are formed spontaneously in suspension-cultured cells of S. tortuosus and in the tips of root hairs formed in sterile callus cultures of S. tortuosus. Callose deposits in root hairs are restricted to root hair tips which appear to be damaged or deformed, while normal root hair tips lack callose deposits. The callose deposits found in suspension culture cells are restricted to regions where unusual outgrowths or protuberances are formed on the cell surfaces, specifically regions that are the sites of new cell wall formation.Callose formation has been shown to be regulated by intracellular calcium levels.

The Method of Plant Water Status Measurement in Sweet Potato (Ipomoea Batatas (L) Lam.)

2010 ◽  
Vol 7 (1) ◽  
Author(s):  
Saraswati Prabawardani
Keyword(s):  
Water Content ◽  
Sweet Potato ◽  
Relative Water Content ◽  
Water Status ◽  
Plant Water Status ◽  
Equilibration Time ◽  
Plant Water ◽  
Font Size ◽  
Potato Leaf ◽  
Relative Water

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning /> <w:ValidateAgainstSchemas /> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables /> <w:SnapToGridInCell /> <w:WrapTextWithPunct /> <w:UseAsianBreakRules /> <w:DontGrowAutofit /> <w:UseFELayout /> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--> <!--[if gte mso 10]> <mce:style><! /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} --> <!--[endif]--> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10pt;">The measurement of plant water status such as leaf water potential (LWP) and leaf relative water content (RWC) is important part of understanding plant physiology and biomass production. Preliminary study was made to determine the optimum amount of leaf abrasion and equilibration time of sweet potato leaf inside the thermocouple psychrometer chambers. Based on the trial, the standard equilibration time curve of a Peltier thermocouple for sweet potato leaf was between 2 and 3 hours. To increase the water vapour conductance across the leaf epidermis the waxy leaf cuticle should be removed or broken by abrasion. The result showed that 4 times leaf rubbings was accepted as the most effective way to increase leaf vapour conductance of sweet potato in the psychrometer chambers. In calculating the leaf relative water content, unstressed water of sweet potato leaves require 4 hours imbibition, whereas water stressed of sweet potato leaves require 5 to 6 hours to reach the saturation time. Either leaf water potential or relative water content can be used as a parameter for plant water status in sweet potato.</span><span style="font-size: 10pt;"> </span></p>

Plant Water Status in Relation to Clouds 1

1973 ◽  
Vol 65 (4) ◽  
pp. 677-678 ◽  
Author(s):  
J. R. Stansell ◽  
Betty Klepper ◽  
V. Douglas Browning ◽  
H. M. Taylor
Keyword(s):  
Water Status ◽  
Plant Water Status ◽  
Plant Water
Sign in / Sign up

Export Citation Format

Share Document