Nitrate Transport and Distribution in Soybean Plants With Dual-Root Systems

Nitrate absorbed by soybean (Glycine max L. Merr.) roots from the soil can promote plant growth, while nitrate transported to nodules inhibits nodulation and nodule nitrogen fixation activity. The aim of this study was to provide new insights into the inhibition of nodule nitrogen (N) fixation by characterizing the transport and distribution of nitrate in soybean plants. In this research, pot culture experiments were conducted using a dual root system of soybeans. In the first experiment, the distribution of 15N derived from nitrate was observed. In the second experiment, nitrate was supplied–withdrawal–resupplied to one side of dual-root system for nine consecutive days, and the other side was supplied with N-free solution. Nitrate contents in leaves, stems, petioles, the basal root of pealed skin and woody part at the grafting site were measured. Nitrate transport and distribution in soybean were analyzed combining the results of two experiments. The results showed that nitrate supplied to the N-supply side of the dual-root system was transported to the shoots immediately through the basal root pealed skin (the main transport route was via the phloem) and woody part (transport was chiefly related to the xylem). There was a transient storage of nitrate in the stems. After the distribution of nitrate, a proportion of the nitrate absorbed by the roots on the N-supply side was translocated to the roots and nodules on the N-free side with a combination of the basal root pealed skin and woody part. In conclusion, the basal root pealed skin and woody part are the main transport routes for nitrate up and down in soybean plants. Nitrate absorbed by roots can be transported to the shoots and then retranslocated to the roots again. The transport flux of nitrate to the N-free side was regulated by transient storage of nitrate in the stems.

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A Minirhizotron Method for Measuring Root System of Soybean Plants Growing in the Field.

Japanese Journal of Crop Science ◽

10.1626/jcs.64.78 ◽

1995 ◽

Vol 64 (1) ◽

pp. 78-85 ◽

Cited By ~ 4

Author(s):

Tadashi HIRASAWA ◽

Masahide TAKEI ◽

Kuni ISHIHARA

Keyword(s):

Root System ◽

Soybean Plants

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Accumulation and Distribution of Fertilizer Nitrogen and Nodule-Fixed Nitrogen in Soybeans with Dual Root Systems

Agronomy ◽

10.3390/agronomy10030397 ◽

2020 ◽

Vol 10 (3) ◽

pp. 397 ◽

Cited By ~ 3

Author(s):

Rui Zhang ◽

Cong Wang ◽

Wenzhi Teng ◽

Jing Wang ◽

Xiaochen Lyu ◽

...

Keyword(s):

Root System ◽

Root Nodules ◽

Culture Conditions ◽

Sand Culture ◽

Nodule Formation ◽

N Fixation ◽

Fertilizer N ◽

N Accumulation ◽

Biological N Fixation ◽

Nodule Growth

The soybean (Glycine max L. Merr.) is a crop with a high demand for nitrogen (N). The root nodules that form in soybeans can fix atmospheric N effectively, yet the goal of achieving high yields cannot be met by relying solely on nodule-fixed N. Nonetheless, the application of N fertilizer may inhibit nodule formation and biological N fixation (BNF), but the underpinning mechanisms are still unclear. In this study, we grafted the roots of non-nodulated soybeans onto nodulated soybeans to generate plants with dual root system. The experiment included three treatments conducted under sand culture conditions with NO 3 − and NH 4 + as N sources. Treatment I: The non-nodulated roots on one side received 50 mg·L−1 15 NO 3 − or 15NH4+, and the nodulated roots on the other side were not treated. Treatment II: The non-nodulated roots received 50 mg·L−1 15 NO 3 − or 15 NH 4 + , and the nodulated roots received 50 mg·L−1 14 NO 3 − or 14 NH 4 + . Treatment III: Both non-nodulated and nodulated roots received 50 mg·L−1 15 NO 3 − or 15 NH 4 + . The results showed the following: (1) Up to 81.5%–87.1% of the N absorbed by the soybean roots and fixed by the root nodules was allocated to shoot growth, leaving 12.9%–18.5% for root and nodule growth. Soybeans preferentially used fertilizer N in the presence of a NO 3 − or NH 4 + supply. After the absorbed fertilizer N and nodule-fixed N was transported to the shoots, a portion of it was redistributed to the roots and nodules. The N required for root growth was primarily derived from the NO 3 − or NH 4 + assimilated by the roots and the N fixed by the nodules, with a small portion translocated from the shoots. The N required for nodule growth was primarily contributed by nodule-fixed N with a small portion translocated from the shoots, whereas the NO 3 − or NH 4 + that was assimilated by the roots was not directly supplied to the nodules. (2) Based on observations of the shoots and one side of the roots and nodules in the dual root system as an N translocation system, we proposed a method for calculating the N translocation from soybean shoots to roots and nodules during the R1–R5 stages based on the difference in the 15N abundance. Our calculations showed that when adding N at a concentration of 50 mg·L−1, the N translocated from the shoots during the R1–R5 stages accounts for 29.6%–52.3% of the N accumulation in nodulated roots (Rootn) and 9.4%–16.6% of the N accumulation in Nodulen of soybeans. Through the study of this experiment, the absorption, distribution and redistribution characteristics of fertilizer N and root nodule N fixation in soybean can be clarified, providing a theoretical reference for analyzing the mechanisms of the interaction between fertilizer N and nodule-fixed N.

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Aspects of nitrogen use efficiency of cauliflower I. A simulation modelling based analysis of nitrogen availability under field conditions

The Journal of Agricultural Science ◽

10.1017/s0021859603003344 ◽

2003 ◽

Vol 141 (1) ◽

pp. 1-16 ◽

Cited By ~ 19

Author(s):

H. KAGE ◽

C. ALT ◽

H. STÜTZEL

Keyword(s):

Root Growth ◽

Soil Water ◽

Nitrogen Availability ◽

Simulation Modelling ◽

Activity Period ◽

Nitrate Transport ◽

Soil Conditions ◽

Residual Soil ◽

Soil Nitrate ◽

N Supply

Data from several field experiments (eight crops grown under a widely varying nitrogen supply on a loess loam soil) were used for a simulation modelling based analysis of nitrogen availability of cauliflower. The model was built out of components describing root growth, nitrate transport to the roots and the vertical nitrate transport within the soil.Root observations obtained over 2 years indicated an increased fraction of dry matter allocated to the fine roots under N deficiency. An adopted version of a root growth model for cauliflower described the rooting data with an R2=0·75. Based upon an acceptable description of the soil water budget, vertical nitrate movement during the growth period of cauliflower was accurately described. The magnitude of this movement, however, was limited to soil depths of about 60 cm even after periods of high rainfall, because of a high soil water holding capacity. An analysis of the factors determining nitrate availability indicated that apparent mass flow was only of high importance for conditions of extremely high N supply where high amounts of nitrate nitrogen remain in the soil up to the end of the growing season. Otherwise, the dominating fraction of nitrate has to be transported to the roots by diffusion. Single root model based calculations of maximum nitrate transport to roots overestimated N availability as indicated by estimates of critical soil nitrate N that were too low. The introduction of a restricted uptake activity period of the roots was used to bridge the gap between theoretical calculations and empirical results. Scenario calculations were carried out to obtain functional relationships between N supply and residual soil nitrate levels for different soil conditions and management practices.

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ASSAY OF RESPONSIVENESS OF THE DIFFERENT SOYBEAN CULTIVARS ON APPLICATION OF BIOPREPARATIONS “BIOTERRA” GROWTH ENERGY AND GUMISTIM

10.25230/conf11-2021-195-200 ◽

2021 ◽

Author(s):

О.V. Leukhina ◽

◽

V.D. Dmitrieva ◽

V.I. Panarina ◽

◽

...

Keyword(s):

Root System ◽

Dry Matter ◽

Cereal Crops ◽

Scientific Center ◽

Positive Effects ◽

Soybean Cultivars ◽

Germination Energy ◽

Soybean Plants ◽

Growth Energy

We studied responsiveness of the different soybean cultivars bred at the Federal Scientific Center of Legumes and Cereal Crops on application of the bio-fertilizers “Bio-Terra” Growth Energy and Gumistim. These preparations had positive effects on germination energy and laboratory germination of seeds and on development of root system and accumulation of dry matter in soybean plants of the cultivars Lantsetnaya and Shatilovskaya 17.

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Effects of Light Level and Nitrogen Supply on the Red Clover–Orobanche Minor Host–Parasite Interaction

Plants ◽

10.3390/plants8060146 ◽

2019 ◽

Vol 8 (6) ◽

pp. 146 ◽

Cited By ~ 2

Author(s):

Joel I. Jokinen ◽

Louis J. Irving

Keyword(s):

Trifolium Pratense ◽

Red Clover ◽

Light Level ◽

Starch Accumulation ◽

N Fixation ◽

Low Light ◽

Leaf Mass Area ◽

N Supply ◽

Potential Competitor ◽

Orobanche Minor

Infection by holoparasitic plants typically causes decreases in host mass, thought to be primarily as a result of resource abstraction. Inverse relationships have been noted between the number of Orobanche spp. parasites infecting a host and their mass, suggesting that the parasites compete for a shared resource pool, assumed to be recently fixed carbon (C). In clover, nitrogen (N) fixation requires a high proportion of daily photosynthate and represents a potential competitor for recently fixed C. We grew Trifolium pratense, either singly or parasitised by Orobanche minor, under high or low light levels, and with or without exogenous N supply. Low light and N deficiency led to decreased host biomass, while the damage caused by parasitism was proportionate to host mass. Parasitism caused reductions in host leaf mass, area, photosynthetic rates and shoot N concentration, but did not affect starch accumulation. Parasite mass as a proportion of system biomass was significantly higher when attached to plants grown at high light, which was attributed to higher photoassimilate supply, while the N supply had no effect. While both N limitation and parasitism caused reductions in host growth, little evidence of competition for C between N fixation and the parasites was noted.

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CHLORIMURON-ETHYL IN CONVENTIONAL AND TRANSGENIC SOYBEAN CULTIVARS UNDER WATER DEFICIT STRESS

Revista Caatinga ◽

10.1590/1983-21252018v31n405rc ◽

2018 ◽

Vol 31 (4) ◽

pp. 832-842

Author(s):

Clebson Gomes Gonçalves ◽

Antonio Carlos da Silva Junior ◽

Maynumi Scarano ◽

Maria Renata Rocha Pereira ◽

Dagoberto Martins

Keyword(s):

Root System ◽

Soil Water ◽

Water Deficit ◽

Dry Weight ◽

Water Deficit Stress ◽

Limiting Factor ◽

Soybean Cultivars ◽

Water Potentials ◽

Chlorimuron Ethyl ◽

Soybean Plants

ABSTRACT Water deficit is a limiting factor for the soybean yield; it triggers different physiological and anatomical adaptations that have deleterious effects on the plants and can affect the selectivity of herbicides, causing production losses. In this context, the objective of this work was to evaluate the action of the chlorimuron-ethyl herbicide when applied at different stages of soybean plants, using conventional and transgenic cultivars, and different soil water potentials. A rate of 20 g ha-1 of the chlorimuron-ethyl herbicide was applied to two soybean cultivars (MG/BR46-Conquista - conventional, and BRS-Valiosa-RR - transgenic) at two phenological stages (V2 - first fully expanded trifoliate leaves, and V4 - third fully expanded trifoliate leaves), using three soil water potentials (-0.03 MPa, -0.07 MPa, and -0.5 MPa). Phytotoxicity, and plant height were evaluated at 3, 7, 14, and 21 days after the herbicide application. The shoot dry weight, root dry weight, and root system nodulation were evaluated. The soybean plants had lower phytotoxicity when subjected to application of chlorimuron-ethyl under water deficit conditions. The use of chlorimuron-ethyl reduced the growth and biomass of soybean plants and affected the plants' root system nodulation. The transgenic cultivar (BRS-Valiosa-RR) presented better performance when subjected to a moderate water deficit (-0.07 MPa), which contributes to biological nitrogen fixation.

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Root and nitrate-N distribution and optimization of N input in winter wheat

Scientific Reports ◽

10.1038/s41598-019-54641-w ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Bin-Bin Guo ◽

Bei-Cheng Liu ◽

Li He ◽

Yang-Yang Wang ◽

Wei Feng ◽

...

Keyword(s):

Winter Wheat ◽

Root System ◽

N Uptake ◽

Root Weight ◽

N Application ◽

Weight Density ◽

N Supply ◽

Nitrate N ◽

N Input ◽

Root Weight Density

AbstractScientific management of nitrogen (N) fertilizer has a significant effect on yield while also reducing the environmental risks. In this study, we conducted field experiments over three years at two different sites (Zhengzhou and Shangshui) in Henan Province, China, using different N application rates (0, 90,180, 270, and 360 kg ha−1) to determine the relationships between soil N supply and N demand in winter wheat (Triticum aestivum L.). Optimal N input was then determined. Both sites showed the same trend. Namely, aboveground N uptake and soil nitrate N (NO3−-N) increased with increasing N, while NO3−-N decreased with increasing soil depth, gradually moving downwards with growth. A significant correlation (p < 0.001) between increasing aboveground N uptake and increasing NO3−-N was also observed under N application, with the best relationships occurring in the 20–60 cm layer during jointing-anthesis (R2 = 0.402–0.431) and the 20–80 cm layer at maturity (R2 = 0.474). Root weight density showed the same spatial-temporal characteristics as NO3−-N, following a unimodal trend with increasing N, and peaking at 90 kg ha−1. The root weight density was mainly distributed in the 0–60 cm layer (above 80%), with the 20–60 cm layer accounting for 30% of the total root system. In this layer, the root weight density was also significantly positively correlated with aboveground N uptake. Wheat yield reached saturation under high N (>270 kg ha−1), with a sharp decrease in N use efficiency (NUE) and linear increase in residual NO3−-N. To balance yield and the risk of environmental pollution in the experimental area, an N application rate of 180–270 kg ha−1 is recommended under sufficient irrigation, thereby supporting a well-developed root system while ensuring balance between N supply and demand.

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