scholarly journals Increasing nitrogen supply to phosphorus-deficient Medicago sativa decreases shoot growth and enhances root exudation of tartrate to discharge surplus carbon dependent on nitrogen form

2021 ◽  
Author(s):  
Honghua He ◽  
Zekun Zhang ◽  
Qi Peng ◽  
Chao Chang ◽  
Rui Su ◽  
...  
Keyword(s):  
Plant Growth ◽  
Shoot Growth ◽  
Root Exudation ◽  
N:P Ratio ◽  
Nitrogen Addition ◽  
Shoot Biomass ◽  
Plant Nitrogen ◽  
N Form ◽  
P Addition ◽  
N Status

Abstract Aims Carboxylate release by roots has been considered a strategy for mobilization and acquisition of phosphorus (P). However, recently, it was argued that carboxylate release may be a way to discharge surplus carbon produced under conditions that limit plant growth. Plant P status may not be the main factor driving carboxylate release by roots. Instead, plant nitrogen (N) status and/or N:P ratio of the soil or plant may play a more important role in enhancing carboxylate release. Methods A greenhouse pot experiment was performed to grow alfalfa in a P-deficient soil, supplied with two rates of P (0 and 20 mg kg− 1) in combination with four forms of nitrogen (N) at five rates (0, 25, 50, 75, and 100 mg kg− 1), to explore the effects of P rate, N form, N rate, and their interactions on plant growth, P and N status, and carboxylate release, and to determine the factors driving carboxylate release. Results Nitrogen addition weakened the positive effect of P addition on plant growth, and increased plant N ([N]) and P concentrations ([P]); P addition increased plant [P], but weakened the effect of N addition on plant [N]. The amount of tartrate increased dramatically with increasing N rate, which decreased shoot growth, depending on N form. At high P supply, tartrate exudation correlated negatively with shoot biomass. Conclusions Nitrogen addition to P-deficient alfalfa decreased shoot growth and enhanced the release of tartrate, likely to discharge surplus carbon; and the effects varied with N form.

Canopy development and hydraulic function in Eucalyptus tereticornis grown in drought in CO2-enriched atmospheres

2007 ◽  
Vol 34 (12) ◽  
pp. 1137 ◽  
Author(s):  
Brian J. Atwell ◽  
Martin L. Henery ◽  
Gordon S. Rogers ◽  
Saman P. Seneweera ◽  
Marie Treadwell ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Shoot Growth ◽  
Co2 Enrichment ◽  
Atmospheric Co2 ◽  
Shoot Biomass ◽  
Eucalyptus Tereticornis ◽  
Growth Responses ◽  
Ambient Conditions ◽  
Long Distance ◽  
Pipe Model

We report on the relationship between growth, partitioning of shoot biomass and hydraulic development of Eucalyptus tereticornis Sm. grown in glasshouses for six months. Close coordination of stem vascular capacity and shoot architecture is vital for survival of eucalypts, especially as developing trees are increasingly subjected to spasmodic droughts and rising atmospheric CO2 levels. Trees were exposed to constant soil moisture deficits in 45 L pots (30–50% below field capacity), while atmospheric CO2 was raised to 700 μL CO2 L–1 in matched glasshouses using a hierarchical, multi-factorial design. Enrichment with CO2 stimulated shoot growth rates for 12–15 weeks in well-watered trees but after six months of CO2 enrichment, shoot biomasses were not significantly heavier (30% stimulation) in ambient conditions. By contrast, constant drought arrested shoot growth after 20 weeks under ambient conditions, whereas elevated CO2 sustained growth in drought and ultimately doubled the shoot biomass relative to ambient conditions. These growth responses were achieved through an enhancement of lateral branching up to 8-fold due to CO2 enrichment. In spite of larger transpiring canopies, CO2 enrichment also improved the daytime water status of leaves of droughted trees. Stem xylem development was highly regulated, with vessels per unit area and cross sectional area of xylem vessels in stems correlated inversely across all treatments. Furthermore, vessel numbers related to the numbers of leaves on lateral branches, broadly supporting predictions arising from Pipe Model Theory that the area of conducting tissue should correlate with leaf area. Diminished water use of trees in drought coincided with a population of narrower xylem vessels, constraining hydraulic capacity of stems. Commensurate with the positive effects of elevated CO2 on growth, development and leaf water relations of droughted trees, the capacity for long-distance water transport also increased.

scholarly journals Morphological and Metabolite Responses of Potatoes under Various Phosphorus Levels and Their Amelioration by Plant Growth-Promoting Rhizobacteria

2021 ◽  
Vol 22 (10) ◽  
pp. 5162
Author(s):  
Leangsrun Chea ◽  
Birgit Pfeiffer ◽  
Dominik Schneider ◽  
Rolf Daniel ◽  
Elke Pawelzik ◽  
...  
Keyword(s):  
Amino Acids ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Shoot Biomass ◽  
Root Surface Area ◽  
Limiting Factor ◽  
P Availability ◽  
P Deficiency ◽  
Plant Growth Promoting ◽  
Growth Promoting

Low phosphorus (P) availability is a major limiting factor for potatoes. P fertilizer is applied to enhance P availability; however, it may become toxic when plants accumulate at high concentrations. Therefore, it is necessary to gain more knowledge of the morphological and biochemical processes associated with P deficiency and toxicity for potatoes, as well as to explore an alternative approach to ameliorate the P deficiency condition. A comprehensive study was conducted (I) to assess plant morphology, mineral allocation, and metabolites of potatoes in response to P deficiency and toxicity; and (II) to evaluate the potency of plant growth-promoting rhizobacteria (PGPR) in improving plant biomass, P uptake, and metabolites at low P levels. The results revealed a reduction in plant height and biomass 60–80% under P deficiency compared to P optimum. P deficiency and toxicity conditions also altered the mineral concentration and allocation in plants due to nutrient imbalance. The stress induced by both P deficiency and toxicity was evident from an accumulation of proline and total free amino acids in young leaves and roots. Furthermore, root metabolite profiling revealed that P deficiency reduced sugars by 50–80% and organic acids by 20–90%, but increased amino acids by 1.5–14.8 times. However, the effect of P toxicity on metabolic changes in roots was less pronounced. Under P deficiency, PGPR significantly improved the root and shoot biomass, total root length, and root surface area by 32–45%. This finding suggests the potency of PGPR inoculation to increase potato plant tolerance under P deficiency.

Nitrogen fertiliser alleviates the disorder straighthead in Australian rice

2006 ◽  
Vol 46 (8) ◽  
pp. 1077 ◽  
Author(s):  
B. W. Dunn ◽  
G. D. Batten ◽  
T. S. Dunn ◽  
R. Subasinghe ◽  
R. L. Williams
Keyword(s):  
Plant Growth ◽  
Growth And Yield ◽  
High Nitrogen ◽  
Physiological Disorder ◽  
N Application ◽  
Nitrogen Fertiliser ◽  
Eastern Australia ◽  
Growing Environment ◽  
Nitrogen Rates ◽  
N Status

Straighthead is a ‘physiological’ disorder of rice, the symptoms being floret sterility, deformed florets and panicles and reduced grain yield. Straighthead in rice is difficult to investigate because of its unpredictable occurrence under field conditions. An experiment was conducted in south-eastern Australia in 1996 to investigate the effect of rate and timing of N fertilisation on growth and yield of rice. The presence of straighthead at this location gave a unique opportunity to study the influence of crop N status. This paper reports the influence of N application on straighthead symptoms during this experiment. A significant reduction of straighthead occurred with higher rates of N application. Application of 250 kg N/ha pre-flood, improved plant growth and vigour with subsequent increased uptake and accumulation of S, P, K, Mg, Cu, Mn and Zn in the plant at panicle initiation. The reduction of straighthead at high nitrogen rates may be due to improved uptake of several essential nutrients, and Cu may be a critical nutrient. This study and earlier observations have shown the application of optimal levels of pre-flood nitrogen to achieve grain yields greater than 10 t/ha may reduce straighthead severity in the Australian rice-growing environment. The results in this paper are not presented as recommendations to growers but a contribution to the currently limited literature on straighthead in Australia.

scholarly journals Nematodes in relation to plant growth, IV. Pratylenchus penetrans (Cobb) on orchard trees.

1962 ◽  
Vol 10 (4) ◽  
pp. 286-296 ◽  
Author(s):  
H. Hoestra ◽  
M. Oostenbrink
Keyword(s):  
Plant Growth ◽  
Shoot Growth ◽  
Sandy Soils ◽  
Good Evidence ◽  
Small Populations ◽  
Pratylenchus Penetrans ◽  
Experimental Conditions ◽  
Nematode Density ◽  
Large Populations ◽  
Considerable Damage

The damage caused by Pratylenchus penetrans in orchards is discussed. In 2 experimental fields containing 4 varieties of apple, there was good evidence of a decrease in yield with increased nematode density before apple seedlings were planted. Heavy nematode infestations reduced shoot growth by more than 50%. A concentration of 100 nematodes per 300 ml. of soil may cause considerable damage. The process of infestation and symptoms of nematode attack under field and experimental conditions are discussed. In clean cultivated orchards on light sandy soils there are often large populations in the roots and very small populations in the soil but on heavier soils, the converse is true. Hoestra & Oostenbrink conclude without doubt that P. penetrans is an important cause of replant problems in orchards. H.R. W. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Effect of Plant Growth Regulators on Shoot Growth of a Columnar Type Apple Tree

2003 ◽  
Vol 2 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Manabu Watanabe ◽  
Akira Suzuki ◽  
Sadao Komori ◽  
Hidetugu Sato
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Shoot Growth ◽  
Apple Tree

scholarly journals Dissecting the genetic architecture of shoot growth in carrot (Daucus carota L.) using a diallel mating design

2017 ◽  
Author(s):  
Sarah D. Turner ◽  
Paul L. Maurizio ◽  
William Valdar ◽  
Brian S. Yandell ◽  
Philipp W. Simon
Keyword(s):  
Weed Control ◽  
Genetic Architecture ◽  
Competitive Ability ◽  
Shoot Growth ◽  
Mixed Model ◽  
Shoot Biomass ◽  
Additive Effects ◽  
Mating Design ◽  
Diallel Mating Design ◽  
Diallel Mating

ABSTRACTCrop establishment in carrot (Daucus carota L.) is limited by slow seedling growth and delayed canopy closure, resulting in high management costs for weed control. Varieties with improved growth habit (i.e. larger canopy and increased shoot biomass) may help mitigate weed control, but the underlying genetics of these traits in carrot is unknown. This project used a diallel mating design coupled with recent Bayesian analytical methods to determine the genetic basis of carrot shoot growth. Six diverse carrot inbred lines with variable shoot size were crossed in WI in 2014. F1 hybrids, reciprocal crosses, and parental selfs were grown in a randomized complete block design (RCBD) with two blocks in CA (2015, 2016) and in WI (2015). Measurements included canopy height, canopy width, shoot biomass, and root biomass. General and specific combining abilities were estimated using Griffing’s Model I. In parallel, additive, inbreeding, epistatic, and maternal effects were estimated from a Bayesian linear mixed model, which is more robust to dealing with missing data, outliers, and theoretical constraints than traditional biometric methods. Both additive and non-additive effects significantly influenced shoot traits, with non-additive effects playing a larger role early in the growing season, when weed control is most critical. Results suggest that early season canopy growth and root size express hybrid vigor and can be improved through reciprocal recurrent selection.Article SummaryBreeding for improved competitive ability is a priority in carrot, which suffers yield losses under weed pressure. However, improvement and in-depth genetic studies for these traits relies on knowledge of the underlying genetic architecture. This study estimated heritable and non-heritable components of carrot shoot growth from a diallel mating design using a Bayesian mixed model. Results directly contribute to improvement efforts by providing estimates of combining ability, identifying a useful tester line, and characterizing the genetic and non-genetic influences on traits for improved competitive ability in carrot.

scholarly journals Microbial Consortium of PGPR, Rhizobia and Arbuscular Mycorrhizal Fungus Makes Pea Mutant SGECdt Comparable with Indian Mustard in Cadmium Tolerance and Accumulation

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 975 ◽  
Author(s):  
Andrey A. Belimov ◽  
Alexander I. Shaposhnikov ◽  
Tatiana S. Azarova ◽  
Natalia M. Makarova ◽  
Vera I. Safronova ◽  
...  
Keyword(s):  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Microbial Consortium ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Indian Mustard ◽  
Arbuscular Mycorrhizal ◽  
Shoot Biomass ◽  
Acetylene Reduction Activity ◽  
Nodule Bacterium

Cadmium (Cd) is one of the most widespread and toxic soil pollutants that inhibits plant growth and microbial activity. Polluted soils can be remediated using plants that either accumulate metals (phytoextraction) or convert them to biologically inaccessible forms (phytostabilization). The phytoremediation potential of a symbiotic system comprising the Cd-tolerant pea (Pisum sativum L.) mutant SGECdt and selected Cd-tolerant microorganisms, such as plant growth-promoting rhizobacterium Variovorax paradoxus 5C-2, nodule bacterium Rhizobium leguminosarum bv. viciae RCAM1066, and arbuscular mycorrhizal fungus Glomus sp. 1Fo, was evaluated in comparison with wild-type pea SGE and the Cd-accumulating plant Indian mustard (Brassica juncea L. Czern.) VIR263. Plants were grown in pots in sterilized uncontaminated or Cd-supplemented (15 mg Cd kg−1) soil and inoculated or not with the microbial consortium. Cadmium significantly inhibited growth of uninoculated and particularly inoculated SGE plants, but had no effect on SGECdt and decreased shoot biomass of B. juncea. Inoculation with the microbial consortium more than doubled pea biomass (both genotypes) irrespective of Cd contamination, but had little effect on B. juncea biomass. Cadmium decreased nodule number and acetylene reduction activity of SGE by 5.6 and 10.8 times, whereas this decrease in SGECdt was 2.1 and 2.8 times only, and the frequency of mycorrhizal structures decreased only in SGE roots. Inoculation decreased shoot Cd concentration and increased seed Cd concentration of both pea genotypes, but had little effect on Cd concentration of B. juncea. Inoculation also significantly increased concentration and/or accumulation of nutrients (Ca, Fe, K, Mg, Mn, N, P, S, and Zn) by Cd-treated pea plants, particularly by the SGECdt mutant. Shoot Cd concentration of SGECdt was twice that of SGE, and the inoculated SGECdt had approximately similar Cd accumulation capacity as compared with B. juncea. Thus, plant–microbe systems based on Cd-tolerant micro-symbionts and plant genotypes offer considerable opportunities to increase plant HM tolerance and accumulation.

scholarly journals The effect of chloride and sulphate application to soil on changes in nutrient content in barley shoot biomass at an early phase of growth

2011 ◽  
Vol 50 (No. 7) ◽  
pp. 295-302 ◽  
Author(s):  
J. Matula
Keyword(s):  
Nitrate Concentration ◽  
Phosphorus Uptake ◽  
Nutrient Status ◽  
Nutrient Content ◽  
Shoot Biomass ◽  
Phosphorus Concentration ◽  
Barley Plant ◽  
Plant Nitrogen ◽  
Labile Phosphorus ◽  
The Impact

In this study experiments primarily aimed at the needs of specification of an adequate soil reserve of labile sulphur were extended by investigations of the impact on interactions in nutrient uptake by a test barley plant. Vegetation (18-day) experiments under controlled conditions of cultivation were conducted on a diverse set of 48 soils from agricultural lands. Before barley sowing the experimental set of soils was divided into two variants: A &ndash; control (with NH<sub>4</sub>Cl application) and B &ndash; response variant [with (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> application], and a uniform dose of 26 mg N/kg soil was used. After the experiment terminated, concentrations of N, N-NO<sub>3</sub><sup>&ndash;</sup>, S, S-SO<sub>4</sub><sup>2&ndash;</sup>, P, K, Mg, Ca, Na, Mn and B were determined. Paired t-test revealed significant differences between the sets of data on variants A and B in barley yield and concentrations of sulphur, sulphate, nitrate, phosphorus and boron in barley plants. Sulphate variant (B) had higher yield of barley, higher concentrations of sulphur, sulphate and boron and lower concentrations of nitrate and phosphorus compared to variant A. The lower concentrations of nitrate and phosphorus could not be reasoned by the effect of dilution resulting from the higher barley yield. A substantial decrease in nitrate concentration was related to better utilisation of plant nitrogen after the nutrient status of soil was adjusted with sulphur. Phosphorus concentration in barley adequately corresponded to the soil reserve of labile phosphorus, but only after the phosphorus concentration in barley markedly decreased to the lower level in (sulphate) variant B. Higher concentration of boron in barley could potentially be related to the depression of phosphorus uptake after sulphate application.

scholarly journals Burkholderia Phytofirmans PsJN Stimulate Growth and Yield of Quinoa under Salinity Stress

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 672 ◽  
Author(s):  
Aizheng Yang ◽  
Saqib Saleem Akhtar ◽  
Qiang Fu ◽  
Muhammad Naveed ◽  
Shahid Iqbal ◽  
...  
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Endophytic Bacteria ◽  
Ion Homeostasis ◽  
Growth And Yield ◽  
Shoot Biomass ◽  
World Population ◽  
Plant Growth Promoting Bacteria ◽  
Ros Scavenging ◽  
Burkholderia Phytofirmans Psjn

One of the major challenges in agriculture is to ensure sufficient and healthy food availability for the increasing world population in near future. This requires maintaining sustainable cultivation of crop plants under varying environmental stresses. Among these stresses, salinity is the second most abundant threat worldwide after drought. One of the promising strategies to mitigate salinity stress is to cultivate halotolerant crops such as quinoa. Under high salinity, performance can be improved by plant growth promoting bacteria (PGPB). Among PGPB, endophytic bacteria are considered better in stimulating plant growth compared to rhizosphere bacteria because of their ability to colonize both in plant rhizosphere and plant interior. Therefore, in the current study, a pot experiment was conducted in a controlled greenhouse to investigate the effects of endophytic bacteria i.e., Burkholderia phytofirmans PsJN on improving growth, physiology and yield of quinoa under salinity stress. At six leaves stage, plants were irrigated with saline water having either 0 (control) or 400 mM NaCl. The results indicated that plants inoculated with PsJN mitigated the negative effects of salinity on quinoa resulting in increased shoot biomass, grain weight and grain yield by 12%, 18% and 41% respectively, over un-inoculated control. Moreover, inoculation with PsJN improved osmotic adjustment and ion homeostasis ability. In addition, leaves were also characterized for five key reactive oxygen species (ROS) scavenging enzyme in response to PsJN treatment. This showed higher activity of catalase (CAT) and dehydroascobate reductase (DHAR) in PsJN-treated plants. These findings suggest that inoculation of quinoa seeds with Burkholderia phytofirmans PsJN could be used for stimulating growth and yield of quinoa in highly salt-affected soils.

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