scholarly journals Leaf Phosphorus Concentration Regulates the Development of Cluster Roots and Exudation of Carboxylates in Macadamia integrifolia

2021 ◽  
Vol 11 ◽  
Author(s):  
Xin Zhao ◽  
Yang Lyu ◽  
Kemo Jin ◽  
Hans Lambers ◽  
Jianbo Shen
Keyword(s):  
Critical Value ◽  
Cluster Roots ◽  
Phosphorus Concentration ◽  
Acid Phosphatases ◽  
P Deficiency ◽  
Cluster Root ◽  
Macadamia Integrifolia ◽  
P Concentration ◽  
Leaf P ◽  
P Supply

Phosphorus (P) deficiency induces cluster-root formation and carboxylate exudation in most Proteaceae. However, how external P supply regulates these root traits in Macadamia integrifolia remains unclear. Macadamia plants were grown hydroponically with seven P levels to characterize biomass allocation, cluster-root development, and exudation of carboxylates and acid phosphatases. Plant biomass increased with increasing P supply, peaking at 5 μM P, was the same at 5–25 μM P, and declined at 50–100 μM P. Leaf P concentration increased with increasing P supply, but shoot biomass was positively correlated with leaf P concentration up to 0.7–0.8 mg P g–1 dry weight (DW), and declined with further increasing leaf P concentration. The number of cluster roots declined with increasing P supply, with a critical value of leaf P concentration at 0.7–0.8 mg P g–1 DW. We found a similar trend for carboxylate release, with a critical value of leaf P concentration at 0.5 mg g–1 DW, but the activity of acid phosphatases showed a gradually-decreasing trend with increasing P supply. Our results suggest that leaf P concentration regulates the development and functioning of cluster roots, with a critical P concentration of 0.5–0.8 mg g–1, above which macadamia growth is inhibited.

Wheat and white lupin differ in root proliferation and phosphorus use efficiency under heterogeneous soil P supply

2011 ◽  
Vol 62 (6) ◽  
pp. 467 ◽  
Author(s):  
Qifu Ma ◽  
Zed Rengel ◽  
Kadambot H. M. Siddique
Keyword(s):  
Root Zone ◽  
White Lupin ◽  
Cluster Roots ◽  
Phosphorus Use Efficiency ◽  
P Deficiency ◽  
Soil P ◽  
P Use Efficiency ◽  
P Concentration ◽  
Use Efficiency ◽  
P Supply

Heterogeneity of soil nutrients, particularly phosphorus (P), is widespread in modern agriculture due to increased adoption of no-till farming, but P-use efficiency and related physiological processes in plants grown in soils with variable distribution of nutrients are not well documented. In a glasshouse column experiment, wheat (Triticum aestivum L.) and white lupin (Lupinus albus L.) were subjected to 50 mg P/kg at 7–10 cm depth (hotspot P) or 5 mg P/kg in the whole profile (uniform P), with both treatments receiving the same amount of P. Measurements were made of plant growth, gas exchange, P uptake, and root distribution. Plants with hotspot P supply had more biomass and P content than those with uniform P supply. The ratios of hotspot to uniform P supply for shoot parameters, but not for root parameters, were lower in L. albus than wheat, indicating that L. albus was better able than wheat to acquire and utilise P from low-P soil. Cluster roots in L. albus were enhanced by low shoot P concentration but suppressed by high shoot P concentration. Soil P supply decreased root thickness and the root-to-shoot ratio in wheat but had little effect on L. albus. The formation of cluster roots in low-P soil and greater proliferation and surface area of roots in the localised, P-enriched zone in L. albus than in wheat would increase plant P use in heterogeneous soils. L. albus also used proportionally less assimilated carbon than wheat for root growth in response to soil P deficiency. The comparative advantage of each strategy by wheat and L. albus for P-use efficiency under heterogeneous P supply may depend on the levels of P in the enriched v. low-P portions of the root-zone and other soil constraints such as water, nitrogen, or potassium supply.

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.

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.

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%.

Significance of intracellular and secreted acid phosphatase enzyme activities, and zinc and calcium interactions, on phosphorus efficiency in wheat, sunflower, chickpea, and lentil cultivars

2008 ◽  
Vol 59 (4) ◽  
pp. 339 ◽  
Author(s):  
Aydin Gunes ◽  
Ali Inal
Keyword(s):  
Acid Phosphatase ◽  
Dry Weight ◽  
Phosphorus Efficiency ◽  
Acid Phosphatases ◽  
Root Dry Weight ◽  
P Concentration ◽  
Significant Difference ◽  
P Supply ◽  
Chickpea Cultivars ◽  
Apase Activity

Phosphorus efficiency (PE), and its relationship with intracellular (APase) and secreted (S-APase) acid phosphatases, anthocyanin accumulation, and calcium and zinc nutrition, were compared among 8 cultivars of each of wheat, sunflower, chickpea, and lentil grown under greenhouse conditions with low and high rates of P supply in a P-deficient calcareous soil. Except for the chickpea cultivars, deficiency of P resulted in significant decreases in shoot dry weight of all the crop cultivars and led to significant decreases in root dry weight in wheat and sunflower, significant increases in root dry weight in chickpea, and no significant difference in root dry weight in lentil. PE differed greatly among species and their cultivars. On average, shoot P concentration in cultivars of wheat, sunflower, chickpea, and lentil increased by 44%, 54%, 47%, and 8%, respectively, with P supply, and the increases in P concentration differed greatly among cultivars of all species. Intracellular leaf APase activity of wheat and lentil cultivars was slightly decreased by P supply, while it was unchanged in sunflower and chickpea cultivars. However, root-secreted acid phosphatase (S-APase) activity was significantly reduced by P supply in wheat, sunflower, and chickpea cultivars. Under low-P conditions, S-APase activities of all species except sunflower were negatively correlated with PE. Phosphorus deficiency increased the anthocyanin concentration of the cultivars of wheat and sunflower, whereas it was usually decreased in cultivars of the P-efficient species chickpea and lentil. In general, concentration of Ca was found to be lower, but Zn concentration was higher, in P-efficient cultivars than in P-inefficient cultivars. The results demonstrated that PE of the cultivars clearly depends on their ability to take up P and Zn, and on secretion of acid phosphatases from their roots under P deficiency. The results also suggest that characteristics of Zn and Ca nutrition should be taken into consideration when screening cultivars of crop species for their P efficiency.

Is there a critical level of shoot phosphorus concentration for cluster-root formation in Lupinus albus?

2008 ◽  
Vol 35 (4) ◽  
pp. 328 ◽  
Author(s):  
Haigang Li ◽  
Jianbo Shen ◽  
Fusuo Zhang ◽  
Caixian Tang ◽  
Hans Lambers
Keyword(s):  
Organic Matter ◽  
Root Formation ◽  
Critical Level ◽  
Lupinus Albus ◽  
White Lupin ◽  
Cluster Roots ◽  
Proton Release ◽  
P Concentration ◽  
Citrate Exudation ◽  
P Supply

This study examined the effects of localised phosphorus (P) supply on cluster-root formation and citrate exudation in white lupin (Lupinus albus L. cv. Kiev Mutant). White lupin plants were grown in nutrient solutions with a range of P supplies in a split-root system with one root half deprived of P and the other root supplied with 0, 2, 5, 8, 10 or 75 μm P. Plants were also grown in soil with or without organic matter added to the top layer. The proportion of cluster roots as a percentage of the total root biomass decreased similarly on both root halves with increasing P supply in the hydroponic experiments. More than 18% of the P taken up by the P-supplied root halves was incorporated into the P-deprived halves. Irrespective of the P supply or organic matter addition in the experiments, the proportion of cluster roots and the rate of citrate exudation decreased sharply with increasing P concentration in the shoots up to a critical level of 2–3 mg P g–1 dry weight. In contrast, the rate of proton release was higher in P-deprived root halves than in P-supplied ones. The formation of cluster roots is regulated by shoot P concentration with a critical level of 2–3 mg g–1. Citrate exudation is predominantly governed by shoot P status, whereas proton release strongly responds to local P supply.

The phosphorus requirement of lettuce

1973 ◽  
Vol 80 (1) ◽  
pp. 111-117 ◽  
Author(s):  
R. Smith ◽  
M. A. Scaife
Keyword(s):  
Adsorption Isotherm ◽  
Sandy Soil ◽  
Maximum Growth ◽  
P Adsorption ◽  
P Concentration ◽  
Phosphorus Requirement ◽  
Optimal Intensity ◽  
P Application ◽  
Leaf P ◽  
P Supply

SummaryThe optimal intensity of P supply for lettuce was investigated in a pot experiment with five soils, six levels of P application (0, 15, 30, 60, 120, 240 ppm) and three times of harvest (2, 3 and 4 weeks after emergence). The P adsorption isotherm for each soil was measured in 0.01 M CaCl2.All soils responded strongly to P application, the amounts required for maximum growth varying from 120 ppm on a sandy soil to 300 ppm on a moss peat. The differences in requirement were related to the P adsorption by the soil, and on all soils a solution P concentration of about 1 ppm resulted in maximum growth.The Optimal leaf P concentration in young lettuce was about 0·6%.

scholarly journals Above- and below-ground resource acquisition strategies determine plant species responses to nitrogen enrichment

2021 ◽  
Author(s):  
Dianye Zhang ◽  
Yunfeng Peng ◽  
Fei Li ◽  
Guibiao Yang ◽  
Jun Wang ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Nutrient Acquisition ◽  
Resource Acquisition ◽  
Cluster Roots ◽  
P Concentration ◽  
Acquisition Strategies ◽  
N Input ◽  
Below Ground ◽  
N Enrichment ◽  
Leaf P

Abstract Background and Aims Knowledge of plant resource acquisition strategies is crucial for understanding the mechanisms mediating the responses of ecosystems to external nitrogen (N) input. However, few studies have considered the joint effects of above-ground (light) and below-ground (nutrient) resource acquisition strategies in regulating plant species responses to N enrichment. Here, we quantified the effects of light and non-N nutrient acquisition capacities on species relative abundance in the case of extra N input. Methods Based on an N-manipulation experiment in a Tibetan alpine steppe, we determined the responses of species relative abundances and light and nutrient acquisition capacities to N enrichment for two species with different resource acquisition strategies (the taller Stipa purpurea, which is colonized by arbuscular mycorrhizal fungi, and the shorter Carex stenophylloides, which has cluster roots). Structural equation models were developed to explore the relative effects of light and nutrient acquisition on species relative abundance along the N addition gradient. Key Results We found that the relative abundance of taller S. purpurea increased with the improved light acquisition along the N addition gradient. In contrast, the shorter C. stenophylloides, with cluster roots, excelled in acquiring phosphorus (P) so as to elevate its leaf P concentration under N enrichment by producing large amounts of carboxylate exudates that mobilized moderately labile and recalcitrant soil P forms. The increased leaf P concentration of C. stenophylloides enhanced its light use efficiency and promoted its relative abundance even in the shade of taller competitors. Conclusions Our findings highlight that the combined effects of above-ground (light) and below-ground (nutrient) resources rather than light alone (the prevailing perspective) determine the responses of grassland community structure to N enrichment.

Relationships of phosphorus concentration in reproductive organs with soil phosphorus availability for tropical rain-forest trees on Mount Kinabalu, Borneo

2018 ◽  
Vol 34 (6) ◽  
pp. 351-363
Author(s):  
Yuki Tsujii ◽  
Kanehiro Kitayama
Keyword(s):  
Reproductive Organs ◽  
Reproductive Organ ◽  
Phosphorus Concentration ◽  
P Availability ◽  
P Deficiency ◽  
P Use Efficiency ◽  
Tree Community ◽  
P Concentration ◽  
Mount Kinabalu ◽  
Use Efficiency

Abstract:Bornean rain forests on phosphorus (P)-poor soils exhibit a high P-use efficiency in the production of reproductive organs (i.e. the inverse of P concentration in reproductive-organ litter). The mechanism underpinning this high P-use efficiency is not known, but is hypothesized to result from dilution of P in a given type of reproductive organ and/or a shift of the community composition of flower/fruit types with decreasing P availability. These hypotheses were tested using eight forests with different soil P availabilities on Mount Kinabalu, Borneo. Mean P concentration per forest by genus in inflorescences was significantly positively correlated with P availability, while that in seeds or pericarps was not significantly correlated. This trend was consistent across 21 genera that we analysed, suggesting that P concentration in seeds is maintained in exchange with the dilution of P in inflorescences. The composition of fruit types in tree community was estimated based on the relative abundances of genera in each forest. The relative abundance of capsulate species, which required less P in pericarps, tended to increase in tree community with decreasing P availability. Therefore, both mechanisms were involved in P-use efficiency. This work provides an insight into the reproductive adaptation of trees to P deficiency.

Acclimation of Photosynthesis and Growth by Cotton to Elevated CO2: Interactions With Severe Phosphate Deficiency and Restricted Rooting Volume

1995 ◽  
Vol 22 (6) ◽  
pp. 955 ◽  
Author(s):  
DJ Barrett ◽  
RM Gifford
Keyword(s):  
Elevated Co2 ◽  
Phosphate Deficiency ◽  
Carbon Gain ◽  
Simple Relationship ◽  
P Concentration ◽  
Co2 Concentrations ◽  
Pot Size ◽  
Leaf P ◽  
Ambient Co2 ◽  
P Supply

Acclimation of photosynthesis and growth at three CO2 concentrations (376, 652 and 935 μmol mol-1) was examined in cotton grown under three growth-limiting phosphate (P) supplies (2.1, 6.1 and 18.2 mg P plant-1) and where biomass allocation between roots and shoots was altered by pots of three different sizes (0.32 × 10-3, 0.72 × 10-3 and 1.56 × 10-3 m3 pot-1). Phosphate supplies were chosen such that carbon gain at ambient CO2 increased linearly with P supply. Relative growth rates of these plants were 5-10-times less and photosynthetic rates 3-16-times less than for cotton supplied with abundant nutrients. Pot sizes were chosen so that root biomass and root:shoot ratios decreased with a decrease in rooting volume. Maximum carboxylation rates per unit leaf area (Vcmax) were lower in leaves grown at two elevated CO2 concentrations, compared with ambient CO2 concentrations, under all P and pot size treatments indicating that acclimation of photosynthesis had occurred. The degree of photosynthetic acclimation to elevated CO2 was not related to the degree by which whole plant carbon gain was stimulated by elevated CO2 concentration at the different P supplies, or to the degree by which allocation to root and shoots was altered by pot size. Thus there is no simple relationship between photosynthetic and growth acclimation by cotton to elevated CO2. At ambient CO2, the maximum carboxylation rate increased linearly with an increase in leaf P per unit area (mg P m-2), but rates were lower at elevated CO2 for a given P content m-2. Vcmax also increased linearly with an increase in leaf P concentration (mg P g-1 structural dry weight). However, values of Vcmax were similar for plants grown at ambient and elevated CO2, for a given P concentration. Acclimation of photosynthesis at elevated CO2 was associated with an increase in leaf starch determined 5 h into the light period. However, increased starch concentration with an increase in P supply was not associated with any decline in Vcmax.

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