Exudation of organic acid anions by tropical grasses in response to low phosphorus availability

Abstract It has been suggested that some tropical grasses can acquire phosphorus (P) from hematite and gypsite by exuding organic acid anions (OAs). However, it remains to be determined exactly which OAs could be involved in each case. The objective of this study was to verify the exudation OAs by ruzigrass (Urochloa ruziziensis), palisade grass (U. brizantha), and Guinea grass (Megathyrsus maximus) as a response to P deficiency. The grasses were grown in leachate columns with adequate and deficient P nutrient solutions. The concentration of OAs in the leacheate and root surface, as well as shoot and root dry matter, and P uptake were determined. Citrate, isocitrate, and malate concentration in leachates and root surfaces increased with P starvation, mainly for the Urochloa grasses. Oxalate exudation was similar for the grasses under adequate P supply, but was lower in Guinea grass under P starvation. Palisade grass showed a higher concentration of total OAs in the root surface than the other species due to a great production of oxalate and isocitrate. Palisade grass showed greater dry matter yields regardless of P deficiency, and Guinea grass always had the higher shoot:root ratio. Urochloa grasses have a higher capacity to cope with low P availability by exuding OAs along with a lower shoot:root ratio than Guinea grass.

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

Journal of Plant Ecology ◽

10.1093/jpe/rtab025 ◽

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.

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Cultivar-Dependent Responses in Plant Growth, Leaf Physiology, Phosphorus Use Efficiency, and Tuber Quality of Potatoes Under Limited Phosphorus Availability Conditions

Frontiers in Plant Science ◽

10.3389/fpls.2021.723862 ◽

2021 ◽

Vol 12 ◽

Author(s):

Leangsrun Chea ◽

Ana Meijide ◽

Catharina Meinen ◽

Elke Pawelzik ◽

Marcel Naumann

Keyword(s):

Tuber Yield ◽

Plant Biomass ◽

P Uptake ◽

Tuber Quality ◽

P Availability ◽

Plant Tolerance ◽

P Deficiency ◽

Leaf Physiology ◽

Use Efficiency

The limited availability of phosphorus (P) in soils causes a major constraint in the productivity of potatoes, which requires increased knowledge of plant adaptation responses in this condition. In this study, six potato cultivars, namely, Agria, Lady Claire, Milva, Lilly, Sieglinde, and Verdi, were assessed for their responses on plant growth, leaf physiology, P use efficiency (PUE), and tuber quality with three P levels (Plow, Pmed, and Phigh). The results reveal a significant variation in the cultivars in response to different P availabilities. P-efficient cultivars, Agria, Milva, and Lilly, possessed substantial plant biomass, tuber yield, and high P uptake efficiency (PUpE) under low P supply conditions. The P-inefficient cultivars, Lady Claire, Sieglinde, and Verdi, could not produce tubers under P deprivation conditions, as well as the ability to efficiently uptake P under low-level conditions, but they were efficient in P uptake under high soil P conditions. Improved PUpE is important for plant tolerance with limited P availability, which results in the efficient use of the applied P. At the leaf level, increased accumulations of nitrate, sulfate, sucrose, and proline are necessary for a plant to acclimate to P deficiency-induced stress and to mobilize leaf inorganic phosphate to increase internal PUE and photosynthesis. The reduction in plant biomass and tuber yield under P-deficient conditions could be caused by reduced CO2 assimilation. Furthermore, P deficiency significantly reduced tuber yield, dry matter, and starch concentration in Agria, Milva, and Lilly. However, contents of tuber protein, sugars, and minerals, as well as antioxidant capacity, were enhanced under these conditions in these cultivars. These results highlight the important traits contributing to potato plant tolerance under P-deficient conditions and indicate an opportunity to improve the P efficiency and tuber quality of potatoes under deficient conditions using more efficient cultivars. Future research to evaluate molecular mechanisms related to P and sucrose translocation, and minimize tuber yield reduction under limited P availability conditions is necessary.

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

10.1101/2020.01.27.921247 ◽

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.

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

Annals of Botany ◽

10.1093/aob/mcz011 ◽

2019 ◽

Vol 124 (6) ◽

pp. 961-968 ◽

Cited By ~ 6

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.

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Modelling nutrient uptake: a possible indicator of phosphorus deficiency

Soil Research ◽

10.1071/s96046 ◽

1997 ◽

Vol 35 (2) ◽

pp. 313 ◽

Cited By ~ 5

Author(s):

D. S. Mendham ◽

P. J. Smethurst ◽

P. W. Moody ◽

R. L. Aitken

Keyword(s):

Nutrient Uptake ◽

Phosphorus Deficiency ◽

Soil Phosphorus ◽

Soil Nutrient ◽

Growth Period ◽

Dry Weight ◽

Root Surface ◽

P Uptake ◽

P Deficiency ◽

Highly Correlated

An understanding of the processes controlling soil nutrient supply and plant uptake has led to process-based models that can predict nutrient uptake and the concentration gradient that develops at the root surface. By using this information, it may be possible to develop an indicator of soil phosphorus status based on the predicted uptake and/or concentration of phosphorus (P) at the root surface. To identify the potential for such a test, the relationships between model output and observed plant growth were examined using data from a published experiment. The experiment was initially designed to investigate the relationship between common indices of soil-available P and the growth of maize (Zea mays) in 26 surface soils from Queensland. There was a high correlation between observed and predicted P uptake, and between relative dry matter yield and predicted P uptake. The predicted concentration of P at the root surface was also highly correlated with P uptake and dry weight increase. It is hypothesised that the short growth period (25 days) was responsible for the high correlation between P uptake and measured soil solution P. The hypothesis that a predicted concentration of P at the root surface or predicted P uptake may be valuable indicators of P deficiency in the longer term still remains to be tested.

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Evaluation of common bean genotypes for phosphorus use efficiency in Eutrophic Oxisol

Bragantia ◽

10.1590/1678-4499.454 ◽

2016 ◽

Vol 75 (2) ◽

pp. 152-163 ◽

Cited By ~ 4

Author(s):

Daiana Alves da Silva ◽

Jose Antonio de Fatima Esteves ◽

João Guilherme Ribeiro Gonçalves ◽

Cleber Vinícius Giaretta Azevedo ◽

Tamires Ribeiro ◽

...

Keyword(s):

Common Bean ◽

Nutrient Deficiency ◽

P Availability ◽

Phosphorus Use Efficiency ◽

P Deficiency ◽

Randomized Design ◽

Low Phosphorus ◽

Use Efficiency ◽

P Application ◽

And Control

ABSTRACT Common bean is one of the most important legumes in Latin America, mostly grown in soils with low phosphorus (P) availability. Thus, this study aimed to evaluate the responses of 20 bean genotypes to P deficiency. The experiment was a completely randomized design in a 2 × 20 factorial arrangement; the first factor consisted of P levels and the second factor, of 20 bean genotypes, with six replications. The substrate was a Red Eutrophic Oxisol with low P content. For application of the P treatments, it was applied simple superphosphate, consisting of two levels: restrictive and control, with the application of 45 and 90 kg∙ha–1 of P2O5, respectively. At 28 days, we observed the first symptoms of nutrient deficiency, with the decrease in the relative chlorophyll index in the restrictive level treatment. In addition, the treatments were effective in differentiating effects of both factors levels of P and genotypes for most traits evaluated relative to shoot, root and grain yield. It was possible to classify the genotypes in relation to use efficiency and responsiveness to P application, according to their average yield performances. Seven genotypes presented better performances for both P levels, being classified as Efficient and Responsive: G 2333, IAC Carioca Tybatã, IAPAR 81, IAC Imperador, IAC Formoso, BRS Esplendor and IPR Tangará; the first four genotypes were also classified as Efficient and Responsive under hydroponic conditions.

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PHOSPHORUS DEFICIENCY IMPAIRS SHOOT REGROWTH OF SUGARCANE VARIETIES

Experimental Agriculture ◽

10.1017/s0014479715000290 ◽

2016 ◽

Vol 53 (1) ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

FERNANDO C. BACHIEGA ZAMBROSI ◽

RAFAEL VASCONCELOS RIBEIRO ◽

EDUARDO CARUSO MACHADO ◽

JÚLIO CÉSAR GARCIA

Keyword(s):

Leaf Area ◽

Biomass Production ◽

Critical Role ◽

P Uptake ◽

Utilization Efficiency ◽

P Availability ◽

P Deficiency ◽

Soil P ◽

Sugarcane Varieties ◽

P Supply

SUMMARYThe shoot regrowth vigour of sugarcane varieties having contrasting phosphorus (P) efficiency was evaluated under varying soil P availability. The P-inefficient (IAC91–1099 and IACSP94–2101) and -efficient (IACSP94–2094 and IACSP95–5000) sugarcane varieties were grown under low (25 mg P kg−1 soil) or high (400 mg P kg−1 soil) P supply at planting. After 90 days (first cycle of growth), the shoots were harvested and regrowth was studied 70–75 days later by evaluating photosynthesis, leaf area formation, biomass production and P uptake. The shoot dry matter (DM) of sugarcane regrowth subjected to a low P supply was genotype-dependent, with the P-efficient varieties exhibiting greater values than the inefficient ones. This result was explained by the greater efficiency of IACSP94–2094 and IACSP95–5000 in acquiring P rather than P utilization efficiency for shoot biomass production. The root P stored during the first cycle of growth would represent only a minor fraction (< 20%) of the total P content in the shoots at the end of the regrowth period. Thus, we argue that the improved shoot P uptake of the P-efficient varieties was related to their ability to sustain P acquisition after harvesting rather than to the remobilization of root P reserves. Moreover, our data revealed that net CO2 assimilation per leaf area was not associated with differential performance among varieties under P deficiency, suggesting a more critical role of total leaf area in photosynthate supply for sugarcane regrowth. In conclusion, sugarcane regrowth is improved in P-efficient varieties under P deficiency conditions, a finding of practical relevance as such ability might benefit the productivity and the longevity of sugarcane ratoons in low P tropical soils.

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Diffusive gradients in thin films predicts crop response better than calcium-acetate-lactate extraction

Nutrient Cycling in Agroecosystems ◽

10.1007/s10705-021-10173-2 ◽

2021 ◽

Author(s):

Benjamin Hill ◽

Jakob Santner ◽

Heide Spiegel ◽

Markus Puschenreiter ◽

Walter W. Wenzel

Keyword(s):

Thin Films ◽

Spring Barley ◽

P Uptake ◽

Calcium Acetate ◽

P Availability ◽

P Deficiency ◽

Soil P ◽

Eastern Austria ◽

Diffusive Gradients ◽

Better Than

AbstractSoil P testing has been widely used to predict crop yields, P uptake, and fertilizer demands in agriculture. Diffusive gradients in thin films (DGT) provides a zero-sink soil P test which mimics diffusion-controlled plant uptake and has previously been found to predict P availability to crops better than conventional quantity-based P tests in highly weathered Australian, though not in European soils. Here we tested the performance of DGT and the Austrian and German standard P quantity test calcium acetate lactate (CAL) to explain the variation of crop yield and P uptake response of winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.) in long-term P fertilization experiments at four different sites in eastern Austria. Phosphorus extracted with DGT (P-DGT) and CAL (P-CAL) correlated well in similar soils but not across sites with large variation in soil and site properties such as carbonate equivalent and water availability. The predictive power of DGT for barley (R2 = 0.42) and wheat grain yield (R2 = 0.32), and P uptake in wheat grains (R2 = 0.36) was clearly superior to that of the CAL, and less dependent on soil properties. The better performance of DGT compared to the quantity test is consistent with diffusion-limited P uptake in the water-limited cultivated soils of eastern Austria. The critical values of P deficiency derived from the Mitscherlich-type fits for barley and wheat at 80% relative yield are 64.9 and 26.2 µg L−1, respectively, consistent with differential P demands of the crops.

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Phosphorus Use Efficiency in Canola Genotypes

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v4i6.424-430.726 ◽

2016 ◽

Vol 4 (6) ◽

pp. 424

Author(s):

Kürşat Korkmaz ◽

Çağatay Altıntaş

Keyword(s):

Dry Matter ◽

Growth Stage ◽

Nutrient Use Efficiency ◽

Dry Weight ◽

Early Growth ◽

Genotypic Differences ◽

P Availability ◽

P Deficiency ◽

Early Growth Stage ◽

Use Efficiency

Phosphorus (P) deficiency is a widespread macronutrient deficiency and is one of the major constraints limiting canola production. Efficient P fertilizer method’s is important for economic production of canola and sustaining of environmental quality. The aim of this research is to investigate P use efficiency (PUE) of canola genotypes at an early growth stage. The experiment was set up as a completely randomized design in a factorial scheme. The factors were ten canola genotypes (Excalibur, Nelson, Vectra, Orkan, Triangel, TKK08-5, Oase, Elvis, Es Hydromel and Licord) and three P rates (0, 50 and 100 mg kg-1). The plant parameters, dry weight of shoot and root varies significantly with P levels in all applications. In general, P concentrations and dry weight of the genotypes are linearly raised by P treatments. The genotype Elvis produced significantly higher shoot dry matter 9.24 g pot-1 at 100 mg kg-1 P rate compared to the other applications. However, without P, dry matter (DM) of genotypes varied between 1.67 to 6.96 g pot-1. Cultivars classified as efficient responsive are: Elvis, inefficient responsive: Nelson, Orkan, Oase, Licord, and efficient nonresponsive: Excalibur, Vectra, Triangel, TKK08-5, Es Hydromel. Plant dry matter can be used for identification of the genotypes which could be adapted to low or high soil P availability conditions at an early growth stage. Nutrient use efficiency and genotypic differences in plants should be considered in order to create an accurate and a balanced fertilizer program as well as improving crop yield in agricultural production system.

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Determination of Increase in Yield of Tropical Grasses Inoculated with Spirillum lipoferum

Journal of Advances in Microbiology ◽

10.9734/jamb/2020/v20i1130296 ◽

2020 ◽

pp. 17-21

Author(s):

N. N. Ngerebara ◽

L. O. Amadi ◽

G. C. Vincent

Keyword(s):

Protein Content ◽

Pearl Millet ◽

Dry Matter ◽

Panicum Maximum ◽

Nitrogen Fixing ◽

Tropical Grasses ◽

Digitaria Decumbens ◽

Guinea Grass ◽

Yield Responses

Increase in yield of tropical grasses viz. digit grass (Digitaria decumbens), guinea grass (Panicum maximum) and pearl millet (Penisetum americanum) inoculated with tropical nitrogen-fixing bacterium, Spirillum lipoferum was investigated. The study was carried out for three consecutive years (2016-2018). Dry matter yields and protein content of the three tropical grasses were used for the assessment. In 2017, pearl millet (Penisetum americanum) and guinea grass (Panicum maximum) produced significantly higher protein content and dry matter yields. Projected yields using regression analysis of both pearl millet and guinea grass indicated that about 40kgN ha-1 yr-1 were replaced by inoculation. Although, protein production of guinea grass was lower during 2018, dry matter yield responses were similar to those of 2017. This research has shown that inoculation with Spirillum lipoferum, a tropical nitrogen-fixing bacterium reduced acetylene and increased yields or reduced nitrogen fertilizer requirement of the tropical grasses as well as replacement of up to 40KgN ha-1. This amount is agro-economically important and suggests the viability and potential for grass-bacteria systems.

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