Plant phosphorus status has a limited influence on the concentration of phosphorus-mobilising carboxylates in the rhizosphere of chickpea

2005 ◽  
Vol 32 (2) ◽  
pp. 153 ◽  
Author(s):  
Madeleine Wouterlood ◽  
Hans Lambers ◽  
Erik J. Veneklaas
Keyword(s):  
Root Systems ◽  
External Factors ◽  
Sand Culture ◽  
P Deficiency ◽  
Cicer Arietinum L ◽  
Split Root ◽  
Chickpea Cultivar ◽  
Phosphorus Status ◽  
Carboxylate Exudation ◽  
P Supply

Two experiments were conducted to investigate whether carboxylate exudation by chickpea (Cicer arietinum L.) is a response to phosphorus (P) deficiency or a constitutive trait. The effect of P supply on carboxylate concentrations in the plant and in the rhizosphere of chickpea cultivar Heera was studied in a sand culture. Plants were grown in pots supplied with 200 mL of solution containing 0–500 μm P every 3 d. Malonate was the main carboxylate exuded, and the main carboxylate in roots; shoots contained mainly citrate and malate. Contrary to what has been reported for other species, carboxylate concentrations in the rhizosphere decreased only slightly at high P supply, but they were still substantial. The effect of P supply on the rate of exudation was studied in a split-root sand culture. Root systems were split into two pots, one root half received no P and the other half received 200 mL of solution containing 0–500 μm P. The rhizosphere of both root halves contained similar concentrations of carboxylates, even when the plants received a different supply of P. Our results indicate that carboxylate exudation is determined by internal P rather than external factors. The fact that chickpea roots always exude carboxylates indicates that exudation in this species is largely constitutive.

Assessment of the phosphorus status of oilseed rape by plant analysis

1989 ◽  
Vol 29 (6) ◽  
pp. 861 ◽  
Author(s):  
A Pinkerton ◽  
K Spencer ◽  
AG Govaars
Keyword(s):  
Field Experiments ◽  
Maximum Yield ◽  
Plant Part ◽  
Plant Analysis ◽  
Triple Superphosphate ◽  
P Deficiency ◽  
P Concentration ◽  
Critical P Concentration ◽  
Phosphorus Status ◽  
P Supply

Phosphorus (P) concentrations in young plants of rapeseed (Brassica napus cv. Wesway) were related to seed and oil yields to develop a tissue test for the diagnosis of P deficiency. Critical P concentrations were defined as those concentrations required to sustain 90% of maximum yield. In 2 field experiments in successive seasons on a P-deficient soil, rates of triple superphosphate from 2.5 to 120 kg/ha were banded with the seed. The lowest P concentration in young shoots (17-19 weeks from sowing) associated with a P supply that was adequate for plant growth was approximately 0.31%. The youngest fully-expanded leaf was a reliable plant part to sample, its P concentration being about 0.05% lower than the concentration of the whole shoot. Critical P concentrations in young plants for sustaining 90% of maximum seed and oil yields were higher, namely 0.33 and 0.28% for whole shoots and youngest fully-expanded leaves respectively. The critical P concentration in seeds was about 0.35%.

Root morphological plasticity and biomass production of two Chinese fir clones with high phosphorus efficiency under low phosphorus stress

2011 ◽  
Vol 41 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Pengfei Wu ◽  
Xiangqing Ma ◽  
Mulualem Tigabu ◽  
Chen Wang ◽  
Aiqin Liu ◽  
...  
Keyword(s):  
Biomass Production ◽  
Morphological Traits ◽  
Southern China ◽  
Chinese Fir ◽  
Phosphorus Efficiency ◽  
Sand Culture ◽  
Root Surface Area ◽  
Limiting Factor ◽  
P Deficiency ◽  
P Supply

Available P is the major growth-limiting factor in southern China where Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook.) plantations are increasingly established. Planting P-efficient clones is a viable option to enhance productivity of Chinese fir plantations. Two Chinese fir clones with high P efficiency (M1 and M4) were chosen as the research materials and their adaptive responses to low P stress were examined. The increment in root morphological traits and biomass production of these clones was measured by a sand culture experiment with a heterogeneous P supply. For both clones, P starvation resulted in significantly higher root surface area and root volume but not root length. For clone M4, the mean root diameter was also larger under P deficiency than under normal P supply. Interestingly, the root morphological traits varied substantially within the same root system where the starved roots had higher values for all morphological traits than the nonstarved ones. Phosphorus starvation did not affect shoot and root biomass or the root to shoot ratio, but the whole-plant biomass increment was large under P deficiency for clone M4. In conclusion, the adaptation to low P stress in these clones is attributed to increased P acquisition and utilization efficiencies.

Effect of phosphorus deficiency in wheat on the infection of roots by Gaeumannomyces graminis var. tritici

1988 ◽  
Vol 39 (4) ◽  
pp. 541 ◽  
Author(s):  
RF Brennan
Keyword(s):  
Phosphorus Deficiency ◽  
Root Systems ◽  
Gaeumannomyces Graminis ◽  
Nodal Roots ◽  
Nodal Root ◽  
Seminal Roots ◽  
Phosphorus Status ◽  
Gaeumannomyces Graminis Var Tritici ◽  
P Supply ◽  
Take All

Wheat was grown in a slightly acidic grey sand at six levels of phosphorus, in the presence or absence of take-all inoculum in a glasshouse experiment. The incidence and severity of take-all was related to the phosphorus supply and the phosphorus status of wheat.Plants grown without P were more severely infected by take-all than those grown at adequate levels of phosphorus. The percentage of both nodal and seminal roots infected by take-all declined as the level of P was increased. The percentage of seminal roots infected was reduced from 35% to 13.7% by increasing the supply of phosphorus from levels severely deficient to those adequate for plant growth. Infection in nodal roots was reduced from 24% to 2.3% as the P supply increased. In both the seminal and nodal root systems, increasing the P supply decreased the length of proximal lesions (closest to seed) and increased the length of root between the crown and the proximal lesions.

scholarly journals Relationships of Gibberellic Acid to Water and Phosphorus in the Growth, Sugar Production, and Enzyme Behavior of Sugarcane

1969 ◽  
Vol 53 (3) ◽  
pp. 149-166
Author(s):  
Alex G. Alexander
Keyword(s):  
Gibberellic Acid ◽  
Water Supply ◽  
Field Experiments ◽  
Maximum Growth ◽  
Sand Culture ◽  
Growth Responses ◽  
P Deficiency ◽  
P Content ◽  
Variable Water ◽  
P Supply

Immature sugarcane was subjected to variable water and phosphorus (P) supply and then treated with foliar gibberellic acid (GA). All plants were grown in sand culture and received initial water and P treatments at 88 days of age. Water regimes of inadequate, adequate, and abundant supply were established with 1, 2, and 4 liters of water per day, respectively. Variable P included 0, 6, and 30 meq./liter. Foliar GA was given as 0-, 0.01-, and 0.10-percent solutions. There were three objectives: 1 To determine the effectiveness of GA as a growth stimulant and regulator of sugar-enzyme relationships under conditions of water and P stress; 2, to explore physiological limits within which GA-enzyme relationships persist; and 3, to explore the enzyme basis of water and P performance under extreme conditions of GA-stimulated growth. The following results were recorded: 1. Both water and GA had greatly increased stalk weight and intemode length 5 weeks after GA treatment. 2. Water supply strongly affected GA-growth responses. Water-deficient plants were proportionately more stimulated by GA than water-rich plants. However, maximum growth required both GA and abundant water. 3. GA appeared to increase the efficiency of water utilization, regardless of the amount of water supplied. 4. Variable water supply severely transformed the behavior patterns of ATP-ase, amylase, invertase and polyphenol oxidase. 5. GA treatment of low-water plants appeared to increase the severity of water shortage. Hydrolytic enzymes were severely retarded by GA when water supply was low, but not when adequate or abundant water was available. On the basis of growth and enzyme data it was proposed that GA caused an internal redeployment of water so that the net quantity available for enzymatic functions was reduced. It was also proposed that GA might decrease the internal water supply while increasing growth, in contrast to the commercial practice of externally withholding water which decreases growth. 6. Low P was inadequate for maximum growth, but severe P deficiency was not achieved. GA was proportionally more effective in promoting fresh weights and internode elongation when P supply was low. 7. GA moderately increased leaf P content when P supply was low. The increase was primarily organic P (PO) and this was attributed to GA suppression of phosphatase and ATP-ase. The significance of GA alteration of PO is discussed. 8. Evidence was found of a GA-induced PO decline mediated by increased amylase activity. 9. Leaf peroxidase was extremely sensitive to P supply, and to GA in P-hungry plants. The enzyme was excessively active in low-P X low-GA plants. 10. It is shown that cane growth and enzymology is far more sensitive to P than field experiments have indicated. The importance of PO, phosphatases and phosphorylase, as contrasted to total P content, is stressed.

Sex-specifically responsive strategies to phosphorus availability combined with different soil nitrogen forms in dioecious Populus cathayana

2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Specific Root Length ◽  
P Uptake ◽  
Root Tip ◽  
P Availability ◽  
P Deficiency ◽  
Populus Cathayana ◽  
Leaf P ◽  
P Supply

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.

scholarly journals Water and phosphorus uptake by upland rice root systems unraveled under multiple scenarios: linking a 3D soil-root model and data

2020 ◽  
Author(s):  
Trung Hieu Mai ◽  
Pieterjan De Bauw ◽  
Andrea Schnepf ◽  
Roel Merckx ◽  
Erik Smolders ◽  
...  
Keyword(s):  
Upland Rice ◽  
Phosphorus Uptake ◽  
Root Systems ◽  
Multiscale Model ◽  
P Uptake ◽  
Water Dynamics ◽  
Small Scale ◽  
P Availability ◽  
P Deficiency ◽  
Plant P Uptake

AbstractBackground and aimsUpland rice is often grown where water and phosphorus (P) are limited and these two factors interact on P bioavailability. To better understand this interaction, mechanistic models representing small-scale nutrient gradients and water dynamics in the rhizosphere of full-grown root systems are needed.MethodsRice was grown in large columns using a P-deficient soil at three different P supplies in the topsoil (deficient, suboptimal, non-limiting) in combination with two water regimes (field capacity versus drying periods). Root architectural parameters and P uptake were determined. Using a multiscale model of water and nutrient uptake, in-silico experiments were conducted by mimicking similar P and water treatments. First, 3D root systems were reconstructed by calibrating an architecure model with observed phenological root data, such as nodal root number, lateral types, interbranch distance, root diameters, and root biomass allocation along depth. Secondly, the multiscale model was informed with these 3D root architectures and the actual transpiration rates. Finally, water and P uptake were simulated.Key resultsThe plant P uptake increased over threefold by increasing P and water supply, and drying periods reduced P uptake at high but not at low P supply. Root architecture was significantly affected by the treatments. Without calibration, simulation results adequately predicted P uptake, including the different effects of drying periods on P uptake at different P levels. However, P uptake was underestimated under P deficiency, a process likely related to an underestimated affinity of P uptake transporters in the roots. Both types of laterals (i.e. S- and L-type) are shown to be highly important for both water and P uptake, and the relative contribution of each type depend on both soil P availability and water dynamics. Key drivers in P uptake are growing root tips and the distribution of laterals.ConclusionsThis model-data integration demonstrates how multiple co-occurring single root phene responses to environmental stressors contribute to the development of a more efficient root system. Further model improvements such as the use of Michaelis constants from buffered systems and the inclusion of mycorrhizal infections and exudates are proposed.

Partitioning of carbon in split root systems of barley: effect of temperature of the root

1994 ◽  
Vol 45 (8) ◽  
pp. 1103-1109 ◽  
Author(s):  
P.E.H. Minchin ◽  
J.F. Farrar ◽  
M.R. Thorpe
Keyword(s):  
Root Systems ◽  
Effect Of Temperature ◽  
Split Root

scholarly journals Estimating the importance of maize root hairs in low phosphorus conditions and under drought

2019 ◽  
Vol 124 (6) ◽  
pp. 961-968 ◽  
Author(s):  
Florian Klamer ◽  
Florian Vogel ◽  
Xuelian Li ◽  
Hinrich Bremer ◽  
Günter Neumann ◽  
...  
Keyword(s):  
Root Hairs ◽  
Specific Root Length ◽  
P Uptake ◽  
Alkaline Soil ◽  
Secondary Effects ◽  
Short Root ◽  
P Deficiency ◽  
P Content ◽  
Low Phosphorus ◽  
P Supply

Abstract Background and Aims Root hairs are single-cell extensions of the epidermis that face into the soil and increase the root–soil contact surface. Root hairs enlarge the rhizosphere radially and are very important for taking up water and sparingly soluble nutrients, such as the poorly soil-mobile phosphate. In order to quantify the importance of root hairs for maize, a mutant and the corresponding wild type were compared. Methods The rth2 maize mutant with very short root hairs was assayed for growth and phosphorus (P) acquisition in a slightly alkaline soil with low P and limited water supply in the absence of mycorrhization and with ample P supply. Key Results Root and shoot growth was additively impaired under P deficiency and drought. Internal P concentrations declined with reduced water and P supply, whereas micronutrients (iron, zinc) were little affected. The very short root hairs in rth2 did not affect internal P concentrations, but the P content of juvenile plants was halved under combined stress. The rth2 plants had more fine roots and increased specific root length, but P mobilization traits (root organic carbon and phosphatase exudation) differed little. Conclusions The results confirm the importance of root hairs for maize P uptake and content, but not for internal P concentrations. Furthermore, the performance of root hair mutants may be biased by secondary effects, such as altered root growth.

Growth and the distribution of phosphorus in wheat developed under various phosphorus and temperature regimes

1986 ◽  
Vol 37 (5) ◽  
pp. 459 ◽  
Author(s):  
GD Batten ◽  
IF Wardlaw ◽  
MJ Aston
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Flag Leaf ◽  
Standard Condition ◽  
Growth Period ◽  
Phosphorus Concentration ◽  
Floral Initiation ◽  
Stages Of Development ◽  
P Deficiency ◽  
P Supply

Experiments were designed to examine the effect of the level and duration of application of phosphorus (P) on yield in wheat and the effect of growth conditions prior to anthesis on the utilisation of P taken up during the early stages of development. In the first experiment, wheat (Triticum aestivum cv. Kite) was grown in sand and supplied with a complete nutrient solution containing either 1 mM phosphate or 0.25 mM phosphate. The supply of P was maintained until grain maturity, or stopped at different stages of development (floral initiation, flag leaf emergence, anthesis). The increase in total plant dry matter over this period ranged from 8.8 to 17.6 g/plant, with the 1.0 mM P supply and from 4.1 to 9.5 g/plant with the 0.25 mM P supply. Supply of P beyond anthesis resulted in more tiller dry matter and increased the P content of the grain, but did not increase grain yield at either level. With 1 mM P to maturity, up to 21% P of the grain P could be attributed to retranslocation of P within the plant after anthesis. With 0.25 mM P to floral initiation, 58% of the grain P could be attributed to such retranslocation. In a second experiment plants (cv. Kite) were grown initially at 18/13�C with 0.25 mM P until floral initiation and thereafter with a P-free solution until maturity. Between floral initiation and anthesis plants were placed in six dayhight temperatures, extending (in 3�C steps) from 15/10�C to 30/25OC, and then returned to the standard condition of 18/13�C. Higher pre-anthesis temperatures reduced the pre-anthesis growth period and the plant height, but increased the leaf phosphorus concentration and uptake of phosphorus per plant in both the pre- and post-anthesis periods. Net CO2 exchange indicated that leaf senescence in P-deficient plants was closely associated with the export of nitrogen as well as the export of P. Grain P increased from 0.15% to 0.3% when the preanthesis temperature was increased from 15/10 to 30/25�C, although grain yield per main culm did not vary greatly. These findings highlight the importance of environmental conditions in determining the level of P deficiency in wheat, and show that grain yield is not limited by the amount of P in the grain.

Reprint of “Contrasting stomatal regulation and leaf ABA concentrations in wheat genotypes when split root systems were exposed to terminal drought”

2014 ◽  
Vol 165 ◽  
pp. 5-14 ◽  
Author(s):  
Renu Saradadevi ◽  
Helen Bramley ◽  
Kadambot H.M. Siddique ◽  
Everard Edwards ◽  
Jairo A. Palta
Keyword(s):  
Root Systems ◽  
Wheat Genotypes ◽  
Stomatal Regulation ◽  
Terminal Drought ◽  
Split Root
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