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PubMed2004

Optimization modeling of plant root architecture for water and phosphorus acquisition.

An optimization model is presented that examines the relationship between root architecture and multiple resource acquisition, specifically water and phosphorus in spatially heterogeneous environments. The basal root growth angle of an individual common bean plant, which determines the orientation and localization of the bulk of the root system, was modeled as the decision variable. The total payoff to the plant, the benefit obtained from water and phosphorus acquisition, minus the costs of spatial competition between roots, is given as a function of the (x,y) coordinates of the basal root in two-dimensional Cartesian space. We obtained a general solution and applied it to four unique environmental cases which are as follows: (1) the case of uniformly distributed water and phosphorus; (2) the case of localized shallow phosphorus; (3) the case of localized deep water; and (4) the case of shallow phosphorus and deep water. The general solution states that the optimal basal root growth angle will occur at the point where the total rate of change in the value of the resources acquired equals the total rate of change in cost that results from locating the root deeper in the soil. An optimizing plant locates its roots deeper in the soil profile until the marginal benefit exactly equals the marginal cost. The model predicts that the basal root angle of an optimizing plant will be shallower for Case 2 and deeper for Case 3, relative to the basal root angle obtained in the case of uniformly distributed water and phosphorus. The optimal basal root angle for Case 4 will depend on the marginal rate of substitution of water availability for phosphorus availability that occurs with depth. Empirical observations of bean root architecture in the greenhouse and in the field confirm model results and are discussed. In addition, the potential importance of phenotypic plasticity and phenotypic variation are discussed in relation to optimization of traits and adaptation to spatially heterogeneous environments.

Adaptation, Physiological↗
PubMed2004

From weeds to crops: genetic analysis of root development in cereals.

Root development of Arabidopsis, Zea mays (maize) and Oryza sativa (rice) differs in both overall architecture and the anatomy of individual roots. In maize and rice, the post-embryonic shoot-borne root system becomes the major backbone of the root stock; in Arabidopsis, the embryonic root system formed by a simple primary root and its lateral roots remains dominant. Recently, several specific root mutants and root-specific genes have been identified and characterized in maize and rice. Interestingly, some of these mutants indicate that the formation of primary-, seminal-, crown- and lateral roots is regulated by alternative root-type-specific pathways. Further analyses of these unique pathways will contribute to the understanding of the complex molecular networks involved in cereal root formation.

Arabidopsis↗
PubMed1995

Bacterial leakage of mineral trioxide aggregate as a root-end filling material.

Previous dye leakage studies have shown that mineral trioxide aggregate leaks significantly less than other commonly used root-end filling materials. This study determined the time needed for Staphylococcus epidermidis to penetrate a 3-mm thickness of amalgam, Super-EBA, Intermediate Restorative Material (IRM), or mineral trioxide aggregate (MTA) as root-end filling materials. Fifty-six single-rooted extracted human teeth were cleaned and shaped using a step-back technique. Following root-end resection, 48 root-end cavities were filled with amalgam, Super-EBA, IRM, or MTA. Four root-end cavities were filled with thermoplasticized gutta-percha without a root canal sealer (+ control), and another four were filled with sticky wax covered with two layers of nail polish (- control). After attaching the teeth to plastic caps of 12-ml plastic vials and placing the root ends into phenol red broth, the set-ups were sterilized overnight with ethylene dioxide gas. A tenth of a microliter of broth containing S. epidermidis was placed into the root canal of 46 teeth (40 experimental, 3 positive, and 3 negative control groups). In addition, the root canals of two teeth with test root-end filling materials and one tooth from the positive and negative control groups were filled with sterile saline. The number of days required for the test bacteria to penetrate various root-end filling materials was determined. Most samples whose apical 3 mm were filled with amalgam, Super-EBA, or IRM began leaking at 6 to 57 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Compounds↗
PubMed1997

Histologic assessment of mineral trioxide aggregate as a root-end filling in monkeys.

Mineral Trioxide Aggregate (MTA) has been shown in a number of experiments to be a potential root-end filling material. The purpose of this study was to examine the periradicular tissue response of monkeys to MTA and amalgam as root-end fillings. The pulps were removed from all the maxillary incisors of three monkeys. The root canals were prepared and filled with laterally condensed guttapercha and sealer, and the access cavities were restored with amalgam. Buccal mucoperiosteal flaps were raised, and root-end resections were performed before root-end cavity preparation with burs. The root-end cavities in half of the teeth were filled with MTA, while amalgam was placed in the other cavities. After 5 months the periradicular tissue response was evaluated histologically. The results showed no periradicular inflammation adjacent to five of six root ends filled with MTA; also five of six root ends filled with MTA had a complete layer of cementum over the filling. In contrast, all root ends filled with amalgam showed periradicular inflammation, and cementum had not formed over the root-end filling material, although it was present over the cut root end. Based on these results and previous investigations, MTA is recommended as a root-end filling material in man.

Aluminum Compounds↗
PubMed1998

Correlation between cortical plate proximity and apical root resorption.

Root resorption is one of the most common iatrogenic sequelae of orthodontic treatment. Recently, root contact with the labial or palatal cortical plate at root apex level during orthodontic tooth movement was reported to be related to root resorption, and dentofacial morphology was suggested to predispose certain persons to root contact with the cortical plate. In this study, we constructed a best-fit straight line for the maxillary palatal cortical plate and set a line for the labial cortical plate from A point to Prosthion point in order to obtain measurements of proximity of root apices with the cortical plates of the maxillary alveolus. We investigated the correlation between apical root resorption and the measured variables. Our findings suggest that root approximation to the palatal cortical plate during orthodontic treatment could explain approximately 12% of the variance observed in the level of root resorption and the maxillary alveolar bone width about 2%. Tooth extrusion and crown lingualization also contributed to root resorption. We concluded that maxillary central incisor apical root resorption is influenced by root approximation to the palatal cortical plate during orthodontic treatment.

Adolescent↗
PubMedDate not supplied

Intrinsic oxygen use kinetics of transformed plant root culture.

Root meristem oxygen uptake, root tip extension rate, and specific growth rate are assessed as a function of dissolved oxygen level for three transformed root cultures. The influence of hydrodynamic boundary layer was considered for all measurements to permit correlation of oxygen-dependent kinetics with the concentration of oxygen at the surface of the root meristem. Oxygen uptake rate is shown to be saturated at ambient conditions, and a saturation level of approximately 300 micromole O2/(cm(3) tissue.hr) was observed for all three of these morphologically diverse root types. In nearly all cases, the observation of a minimum oxygen pressure, below which respiration, extension, or root growth would not occur, could be accounted for as a boundary layer mass transfer resistance. The critical oxygen pressure below which respiration declines is below saturated ambient oxygen conditions. In contrast, critical oxygen pressures for root tip extension were much higher; extension was nearly linear for the two thicker root types (Hyoscyamus muticus, henbain; Solanum tuberosum, potato) above ambient oxygen levels. The performance of the thinnest root, Brassica juncea (Indian mustard) was consistent with reduced internal limitations for oxygen transport. Extension rates did not correlate with biomass accumulation. The fastest growing henbain culture micro = 0.44 day(-)(1)) displayed the slowest extension rate (0.16 mm/hr), and the slowest growing mustard culture (micro = 0.22 day(-)(1)) had the fastest tip extension rate (0.3 mm/hr). This apparent paradox is explained in terms of root branching patterns, where the root branching ratio is shown to be dependent upon the oxygen-limited mersitem extension rate. The implications of these observations on the performance of root culture in bioreactors is discussed.

Brassica↗
PubMedDate not supplied

Hyperaccumulation of nickel by hairy roots of alyssum species: comparison with whole regenerated plants.

Hairy roots were used to investigate nickel uptake by the hyperaccumulator species, Alyssum bertolonii, A. tenium, and A. troodii. The Ni biosorption capacity of A. tenium hairy roots was lower than for other types of biomass such as bacteria and algae; in short-term (9-h) equilibrium studies, the highest Ni content measured in the roots was 17 500 microg g(-1) dry weight at a liquid concentration of about 4000 ppm. Using long-term hairy root cultures, it was demonstrated that Ni tolerance and hyperaccumulation do not necessarily depend on the presence of shoots or root-shoot translocation. A. bertolonii hairy roots remained healthy in appearance and continued to grow in the presence of 20-100 ppm Ni, accumulating up to 7200 microg g(-1) dry weight Ni. In contrast, hairy roots of Nicotiana tabacum turned dark brown at 20 ppm Ni and growth was negligible. The ability to grow at high external Ni concentrations allowed hyperaccumulator hairy roots to remove much greater amounts of heavy metals from the culture liquid than nonhyperaccumulator hairy roots, even though biomass Ni concentrations were similar. Although hairy roots proved to be a useful tool for investigating Ni hyperaccumulation, there were significant differences in the Ni uptake capacity of hairy roots and whole plants. Regenerated plants of A. tenium were much more tolerant of Ni and capable of accumulating higher Ni concentrations than hairy roots of this species.

Culture Techniques↗
PubMed1997

The consequence of peroxidase overexpression in transgenic plants on root growth and development.

Transgenic tobacco plants that overproduce the tobacco anionic peroxidase wilt upon reaching maturity, although having functional stomata and normal vascular anatomy and physiology. These plants were examined further to determine the cause for wilting, and thus better understand how the anionic peroxidase functions in plant growth and development. Shoots from young peroxidase overproducing plants were grafted onto wild-type tobacco root stock to determine if the roots could absorb and transmit sufficient water to maintain leaf turgidity. These grafted plants never wilted when grown in the greenhouse though shoot peroxidase activity remained ten-fold greater than in control plants, thus indicating that wilting is a consequence of peroxidase expression in the roots. Close examination of root systems revealed considerably less root mass in the transformed plant, primarily exhibited through a decrease in branching. At flowering, root growth rate and total root mass in transformed plants were less than 50% of control plants although shoot mass and growth rate were unchanged. This is in contrast to root growth in young seedlings where transformed plants performed equivalently to controls. Root hydraulic conductivity was measured to evaluate the effect of elevated peroxidase expression on water absorption and transport; however, no significant change in hydraulic conductivity was found in transformed plants. The consequence of anionic peroxidase overexpression on indoleacetic acid (IAA) metabolism was also examined. No significant difference in IAA levels was observed; however, root elongation in plants overexpressing peroxidase was insensitive to exogenous IAA. It can be concluded that the overexpression of the tobacco anionic peroxidase in transformed plants results in diminished root mass from fewer root branches, which contributes to the wilting phenomenon seen in these plants. Further, this developmental change in transformed plants may be a consequence of the metabolism of IAA by the anionic peroxidase.

Indoleacetic Acids↗
PubMed2001

The standardized-taper root canal preparation--Part 2. GT file selection and safe handpiece-driven file use.

AIM: To present guidelines on GT file selection, and safe operation. SUMMARY: It is not necessary to remove excessive dentine for effective root canal preparation. GT files allow safe, standardized preparation, and should be selected to fit the case in hand. Small Root canals should be prepared with 0.06 and 0.08 taper GT files, whilst Large Root canals should be prepared with 0.10 GT or 0.12 Accessory GT files. The greatest challenge is un-learning habits acquired from traditional instrumentation methods. GT files should be used with light touch, and without up-down pumping motions. Spin speeds should be controlled below 300 r.p.m. for routine preparation. GT files are subject to fatigue and should be tracked to avoid overuse. It is recommended that GT files are discarded after the equivalent of five root canal preparations. For severe curvatures, GT files should be single-case tools. KEY LEARNING POINTS: The standard GT file set comprises three instruments of 0.06, 0.08 and 0.10 taper. All are size 20 at the tip, and have a maximum diameter of 1 mm. Accessory GT files have a standard taper 0.12, and maximum diameter of 1.5 mm. They are available in tip sizes 35, 50 and 70. Large Roots are lower canines, upper anteriors, upper and lower single-rooted premolars, palatal roots of upper molars and distal roots of lower molars. They should be prepared with 0.10 GT or 0.12 Accessory GT files. Small Roots are lower incisors, multirooted premolars, buccal roots of upper molars and mesial roots of lower molars. They should be prepared with 0.06 or 0.08 GT files. All GT files should be used with light force and at the correct spin speed. GT files should be discarded after the equivalent of five root canal uses.

Bicuspid↗
PubMed2003

Periapical health and treatment quality assessment of root-filled teeth in two Canadian populations.

AIM: The prevalence of apical periodontitis (AP) and the quality of root fillings and restorations were determined in two Canadian populations differing in avail-ability of endodontists. METHODOLOGY: Radiographs of first-time university patients aged 25-40 years in Toronto and Saskatoon were examined for missing teeth, presence and standard of root fillings, standard of restoration, and AP according to the Periapical Index. Patients with root-filled teeth were invited for clinical examination and interview to inspect the restorations, and to reveal the providers of endodontic treatment and reasons for extractions of missing teeth. Chi-square and independent t-tests interpreted at the 5% significance level were used to examine associations between the prevalence of AP in root-filled teeth and the standard of the root filling, restoration, and providers of treatment. RESULTS: Proportion of patients with root-filled teeth was significantly higher (P < 0.001) in Toronto than in Saskatoon (39 and 26%, respectively). Presence of AP about root-filled teeth (44% in Toronto, 51% in Saskatoon) was significantly associated with poor density (OR = 2.7) short (OR = 2.4) and long (OR = 2.8) root fillings, and with poor radiographic quality of the restoration (OR = 1.7) Prevalence of AP did not differ significantly between teeth treated by generalists and endodontists. CONCLUSIONS: The prevalence of AP in root-filled and untreated teeth was comparable to that reported in previous methodologically compatible studies. The quality of both the root filling and the restoration were found to impact on the periapical health of root-filled teeth, with the impact of the restoration being most critical when the quality of the root filling was adequate.

Adult↗
PubMed2000

Short root mutant of Lotus japonicus with a dramatically altered symbiotic phenotype.

Legume plants carefully control the extent of nodulation in response to rhizobial infection. To examine the mechanism underlying this process we conducted a detailed analysis of the Lotus japonicus hypernodulating mutants, har1-1, 2 and 3 that define a new locus, HYPERNODULATION ABERRANT ROOT FORMATION (Har1), involved in root and symbiotic development. Mutations in the Har1 locus alter root architecture by inhibiting root elongation, diminishing root diameter and stimulating lateral root initiation. At the cellular level these developmental alterations are associated with changes in the position and duration of root cell growth and result in a premature differentiation of har1-1 mutant root. No significant differences between har1-1 mutant and wild-type plants were detected with respect to root growth responses to 1-aminocyclopropane1-carboxylic acid, the immediate precursor of ethylene, and auxin; however, cytokinin in the presence of AVG (aminoetoxyvinylglycine) was found to stimulate root elongation of the har1-1 mutant but not the wild-type. After inoculation with Mesorhizobium loti, the har1 mutant lines display an unusual hypernodulation (HNR) response, characterized by unrestricted nodulation (hypernodulation), and a concomitant drastic inhibition of root and shoot growth. These observations implicate a role for the Har1 locus in both symbiotic and non-symbiotic development of L. japonicus, and suggest that regulatory processes controlling nodule organogenesis and nodule number are integrated in an overall mechanism governing root growth and development.

Mutation↗
PubMed1999

Dual pathways for regulation of root branching by nitrate.

Root development is extremely sensitive to variations in nutrient supply, but the mechanisms are poorly understood. We have investigated the processes by which nitrate (NO3-), depending on its availability and distribution, can have both positive and negative effects on the development and growth of lateral roots. When Arabidopsis roots were exposed to a locally concentrated supply of NO3- there was no increase in lateral root numbers within the NO3--rich zone, but there was a localized 2-fold increase in the mean rate of lateral root elongation, which was attributable to a corresponding increase in the rate of cell production in the lateral root meristem. Localized applications of other N sources did not stimulate lateral root elongation, consistent with previous evidence that the NO3- ion is acting as a signal rather than a nutrient. The axr4 auxin-resistant mutant was insensitive to the stimulatory effect of NO3-, suggesting an overlap between the NO3- and auxin response pathways. High rates of NO3- supply to the roots had a systemic inhibitory effect on lateral root development that acted specifically at the stage when the laterals had just emerged from the primary root, apparently delaying final activation of the lateral root meristem. A nitrate reductase-deficient mutant showed increased sensitivity to this systemic inhibitory effect, suggesting that tissue NO3- levels may play a role in generating the inhibitory signal. We present a model in which root branching is modulated by opposing signals from the plant's internal N status and the external supply of NO3-.

Ammonium Chloride↗
PubMed2006

Response of rice (Oryza sativa) with root surface iron plaque under aluminium stress.

BACKGROUND AND AIMS: Rice (Oryza sativa) is an aquatic plant with a characteristic of forming iron plaque on its root surfaces. It is considered to be the most Al-tolerant species among the cereal crops. The objective of this study was to determine the effects of root surface iron plaque on Al translocation, accumulation and the change of physiological responses under Al stress in rice in the presence of iron plaque. METHODS: The japonica variety rice, Koshihikari, was used in this study and was grown hydroponically in a growth chamber. Iron plaque was induced by exposing the rice roots to 30 mg L(-1) ferrous iron either as Fe(II)-EDTA in nutrient solution (6 d, Method I) or as FeSO(4) in water solution (12 h, Method II). Organic acid in root exudates was retained in the anion-exchange resin and eluted with 2 m HCl, then analysed by high-performance liquid chromatography (HPLC) after proper pre-treatment. Fe and Al in iron plaque were extracted with DCB (dithionite-citrate-bicarbonate) solution. KEY RESULTS AND CONCLUSIONS: Both methods (I and II) could induce the formation of iron plaque on rice root surfaces. The amounts of DCB-extractable Fe and Al on root surfaces were much higher in the presence of iron plaque than in the absence of iron plaque. Al contents in root tips were significantly decreased with iron plaque; translocation of Al from roots to shoots was significantly reduced with iron plaque. Al-induced secretion of citrate was observed and iron plaque could greatly depress this citrate secretion. These results suggested that iron plaque on rice root surfaces can be a sink to sequester Al onto the root surfaces and Fe ions can pre-saturate Al-binding sites in root tips, which protects the rice root tips from suffering Al stress to a certain extent.

Adsorption↗
PubMed2002

Aluminium-induced growth inhibition is associated with impaired efflux and influx of H+ across the plasma membrane in root apices of squash (Cucurbita pepo).

It is generally understood that the inhibition of growth of root apices is the initial effect caused by aluminium (Al) toxicity. The correlation between impaired H+-fluxes across the plasma membrane (PM) and Al-induced growth inhibition, Al accumulation and callose formation in root apices of squash (Cucurbita pepo L. cv. Tetsukabuto) is reported here. The root inhibition was dependent on Al concentration, and the duration of exposure, with the damage occurring preferentially in regions with high Al accumulation and callose formation. Using the fluorescent Al indicator (Morin), Al was localized in the cell walls of the root-tip cells after 3 h and in the whole root-tip cells after 6 h of the Al treatment (50 micro M). The inhibition of H+-pumping rate in the highly purified PM vesicles obtained from the Al-treated apical root portions (1 cm) coincided with the inhibition of root growth under Al stress. Furthermore, H+-ATPase activity of PM vesicles prepared from the control root apices was strongly inhibited by Al in vitro in a dose-dependent manner. Approximately 50% inhibition was observed when PM vesicles were preincubated at Al concentration as low as 10 micro M followed by the enzyme assay in the medium without Al. Using the pH indicator (bromocresol purple), it is shown that surface pH of the control (0 Al) root apices was strongly alkalized from the starting pH of 4.5 in a time-dependent manner. By contrast, the surface pH changed only slightly in the Al-treated root apices. The changes in surface pH mediated by altered dynamics of H+ efflux and influx across the root tip PM play an important role in root growth as affected by Al.

Aluminum↗
PubMed2003

Nitrate-independent expression of plant nitrate reductase in Lotus japonicus root nodules.

Nitrate-independent nitrate reductase (NR) activity is generally found in legume root nodules. Therefore, the effects of nitrate on plant NR activity and mRNA were investigated in the root nodules of Lotus japonicus (L. japonicus). Both NR activity and mRNA levels in roots and root nodules were up-regulated by the addition of nitrate. In the absence of nitrate, NR activity and mRNA were detected in root nodules but not in roots. Southern blotting analysis indicates that NR is encoded by a single gene in L. japonicus. No nitrate was detected in the root nodules or roots of plants grown in the absence of nitrate, while its accumulation was observed in plants supplied with exogenous nitrate. These results indicate that inducible-type NR can be expressed in root nodules in the absence of nitrate. The activation state of the nitrate-independent activity of NR was as high as that of NR activity induced by nitrate. NR mRNA expressed independently of nitrate in root nodules without nitrate was localized in the infected regions of the root nodules. Thus, the expression could be related to the specific structure and environment of root nodules.

Amino Acid Sequence↗
PubMed2003

Investigation into the ability of roots of the poikilohydric plant Craterostigma plantagineum to survive dehydration stress.

The ability of the root system of the poikilohydric plant Craterostigma plantagineum to survive dehydration was investigated. The data presented here reveal that the root system is capable of surviving dehydration, but shortly after rehydration the root system senesces. Two weeks after rehydration the growth of a complete new root system is initiated. During dehydration sucrose accumulates from 36 to a maximum of 111 micromol g-1 DW in the roots. It is suggested that the accumulation of sucrose protects the root system during dehydration. There are major stores of stachyose in the roots of Craterostigma (making up over 40% of the dry weight of the tissue) and during dehydration these stores are metabolized. It is suggested that these stachyose stores act as carbohydrate reserves for the synthesis of sucrose. However, over 350 micromol g-1 DW stachyose is metabolized in the roots, which is well in excess of that required for the accumulation of sucrose observed. It is likely that the stachyose reserves in the root system are translocated to other regions of the plant to support carbohydrate metabolism during dehydration of the tissue. During rehydration, the stachyose reserves return to their original level within 96 h. There is no change in the elevated sucrose content of the roots over this period. Thus the roots maintain the protective properties of sucrose much longer than they are needed. The maintenance of high sucrose contents in rehydrating roots is discussed as a possible survival strategy against recurrent desiccation events.

Carbohydrate Metabolism↗
PubMed2004

Internal axial light conduction in the stems and roots of herbaceous plants.

In order to reveal any roles played by stems and roots of herbaceous plants in responding to the surrounding light environment, the optical properties of the stem and root tissues of 18 herbaceous species were investigated. It was found that light was able to penetrate through to the interior of the stem and was then conducted towards the roots. Light conduction was carried out within the internodes and across the nodes of the stem, and then in the roots from the tap root to lateral roots. Light conduction in both the stem and root occurred in the vascular tissue, usually with fibres and vessels serving as the most efficient axial light conductors. The pith and cortex in many cases were also involved in axial light conduction. Investigation of the spectral properties of the conducted light made it clear that only the spectral region between 710 nm and 940 nm (i.e. far-red and near infra-red light) was the most efficiently conducted in both the stem and the root. It was also found that there were light gradients in the axial direction of the stem or root, and the light intensity generally exhibited a linear attenuation in accord with the distance of conduction. These results revealed that tissues of the stem and root are bathed in an internal light environment enriched in far-red light, which may be involved in phytochrome-mediated metabolic activities. Thus, it appears that light signals from above-ground directly contribute to the regulation of the growth and development of underground roots via an internal light-conducting system from the stem to the roots.

Light↗
PubMed2005

Systemic suppression of cluster-root formation and net P-uptake rates in Grevillea crithmifolia at elevated P supply: a proteacean with resistance for developing symptoms of 'P toxicity'.

Grevillea crithmifolia R. Br. is a species of Proteaceae that is resistant to developing P-toxicity symptoms at phosphorus supplies in the root environment that induce P-toxicity symptoms in the closely related Hakea prostrata (Proteaceae). It was discovered previously that development of P-toxicity symptoms in H. prostrata is related to its low capacity to down-regulate net P-uptake rates (i.e. its low plasticity). The plasticity of net P-uptake rates and whole-plant growth responses in G. crithmifolia has now been assessed in two separate experiments: (i) a range of P, from 0 to 200 micromol P d-1, was supplied to whole root systems; (ii) using a split-root design, one root half was supplied with 0, 3, 75, or 225 micromol P d-1, while the other root half invariably received 3 micromol P d-1. Fresh mass was significantly greater in G. crithmifolia plants that had received a greater daily P supply during the pretreatments, but symptoms of P toxicity were never observed. Cluster-root growth decreased from about half the total root fresh mass when the leaf [P] was lowest (c. 0.1 mg P g-1 DM) to complete suppression of cluster-root growth when leaf [P] was 1-2 mg P g-1 DM. Split-root studies revealed that cluster-root initiation and growth, and net P-uptake rates by roots were regulated systemically, possibly by shoot P concentration. It is concluded that, in response to higher P supply, G. crithmifolia does not develop symptoms of P toxicity because of (i) greater plasticity of its net P-uptake capacity, and (ii) its greater plasticity for allocating P to growth and P storage in roots. This ecologically important difference in plasticity is most probably related to a slightly higher nutrient availability in the natural habitat of G. crithmifolia when compared with that of H. prostrata.

Acclimatization↗