Mobilization of stored nitrate in broccoli (Brassica oleracea var. italica)

1995 ◽  
Vol 75 (3) ◽  
pp. 709-715 ◽  
Author(s):  
Liangxue Liu ◽  
Barry J. Shelp
Keyword(s):  
Brassica Oleracea ◽  
Nitrate Removal ◽  
Xylem Sap ◽  
Plant Size ◽  
Nitrate Content ◽  
Dry Matter Accumulation ◽  
Inflorescence Development ◽  
Sodium Potassium ◽  
Nitrate Supply ◽  
Sulphate Salts

The study tested the hypothesis that substitution of nitrate supply with other anions induces the mobilization of stored nitrate in broccoli (Brassica oleracea var. italica) plants. Broccoli plants, grown under greenhouse conditions in soilless culture, were provided with either a continuous supply of nitrate in the nutrient solution until commercial maturity, or with a nitrate supply only up to inflorescence emergence. At inflorescence emergence, nitrate was also substituted with various chloride or sulphate salts of sodium, potassium and ammonium (15 and 5 mmol L−1). During the period of inflorescence development studied, plant size increased by two- to threefold. Nitrate removal or its substitution with chloride or sulphate salts of sodium and potassium (15 mmol L−1) resulted in 13% less dry-matter accumulation and 63–97% less xylem-sap nitrate than continuous nitrate supply, and 57–62% decline in the plant-nitrate content found at inflorescence emergence. In contrast, chloride or sulphate salts of ammonium (5 mmol L−1) sustained plant growth, while also decreasing xylem-sap nitrate by 83–90% and plant-nitrate content by 58–62%. Phloem-exudate nitrate of plants receiving nitrate continuously was only 7% of that of xylem sap, and was decreased by 63% by an interrupted nitrate supply. Therefore, the removal of nitrate and substitution with a low supply of ammonium, rather than other anions, is recommended for decreasing plant-nitrate content. Key words: Broccoli, chloride, mobilization, nitrate, sulphate

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

scholarly journals An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3390
Author(s):  
Hui Zhang ◽  
Lin Song ◽  
Xiaolin Chen ◽  
Pengcheng Li
Keyword(s):  
Growth Rate ◽  
Bacillus Subtilis ◽  
Nitrate Removal ◽  
Denitrifying Bacteria ◽  
Soil Salinization ◽  
Nitrate Content ◽  
Weak Efficiency ◽  
N Accumulation ◽  
N Removal ◽  
Intensively Managed

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3−-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3−-N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2−-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.

Impact of chloride on nitrate absorption and accumulation by broccoli (Brassica oleracea var. italica)

1996 ◽  
Vol 76 (2) ◽  
pp. 367-377 ◽  
Author(s):  
Liangxue Liu ◽  
Barry J. Shelp
Keyword(s):  
Brassica Oleracea ◽  
Total Nitrogen ◽  
Nitrogen Concentration ◽  
Xylem Sap ◽  
Phloem Exudate ◽  
Nitrate Accumulation ◽  
Total Nitrogen Concentration ◽  
Nitrate Absorption ◽  
Final Yield ◽  
Chloride Treatment

In the present study, we tested the hypothesis that continuous chloride treatment decreases nitrate absorption and accumulation by broccoli (Brassica oleracea var. italica) plants. In a field experiment, both fresh and dry weights of shoot and inflorescence increased linearly with increasing nitrogen applied (70–130 kg ha−1). Chloride application (0–450 kg ha−1) did not significantly affect the final yield. In a greenhouse experiment in which the plants were grown in soilless culture and supplied with 10–18 mmol L−1 nitrate, only the fresh weights of shoot and inflorescence decreased linearly with increasing chloride application (0–45 mmol L−1). In both experiments, increasing chloride application slightly decreased the concentrations of nitrate nitrogen and total nitrogen in xylem sap, and increased the chloride concentrations of both xylem sap and phloem exudate and the total-nitrogen concentration of phloem exudate. The shoot-nitrate contents increased with increasing nitrogen application and decreased with increasing chloride application, whereas the shoot-chloride contents increased with increasing chloride application and decreased with increasing nitrate application. The total-nitrogen contents of the shoot were not affected by chloride application. These data are interpreted to suggest that nitrate absorption was not inhibited by the presence of chloride in the growing medium and that the decrease in nitrate accumulation of the shoot resulted from the stimulation of organic-nitrogen formation from absorbed nitrate. Key words: Antagonism, broccoli, chloride, interaction, nitrate

Broccoli (Brassica oleracea var. italica) cultivar response to boron deficiency

1992 ◽  
Vol 72 (3) ◽  
pp. 883-888 ◽  
Author(s):  
B. J. Shelp ◽  
R. Penner ◽  
Z. Zhu
Keyword(s):  
Brassica Oleracea ◽  
Nutrient Solution ◽  
Nutrient Deficiency ◽  
Boron Deficiency ◽  
Fresh Weight ◽  
High Susceptibility ◽  
Inflorescence Development ◽  
Shoot Fresh Weight ◽  
Young Leaves ◽  
Percent Decline

Broccoli (Brassica oleracea var. italica) cultivar, Commander, characterized by low susceptibility to the hollow stem disorder commonly associated with boron (B) deficiency was compared to one with high susceptibility (cv. Stolto) and to two which are grown commercially (cvs. Baccus and Premium Crop). Beginning 3 wk after germination plants grown in a glasshouse in vermiculite were supplied continuously with a nutrient solution containing adequate B (0.5 mg L−1) or none (deficient), or were supplied initially with 0.5 mg B L−1 up to the initiation of inflorescence development after which no B was supplied. All cultivars showed visible symptoms of B deficiency (leaf midrib cracking, stem corkiness, necrotic lesions and hollowing in the stem pith) and reductions in shoot fresh weight with the zero B treatment, but Commander was least affected. Also, the B concentrations of the florets from Commander were highest and showed the lowest percent decline relative to the 0.5 mg B L−1 treatment. When B was removed from the nutrient solution at initiation of inflorescence development, the B concentrations of the florets and young leaves of all cultivars were higher than in the zero B treatment. Compared to the 0.5 mg B L−1 treatment, the B concentrations of old leaves from all cultivars were reduced, but only in Premium Crop was the floret B significantly decreased.Key words: Boron nutrition, Brassica, broccoli, nutrient deficiency, retranslocation

The narrow-leafed lupin (Lupinus angustifolius L.) as a nitrogen-fixing rotation crop for cereal production. I. Indices of nitrogen fixation

1988 ◽  
Vol 39 (6) ◽  
pp. 1003 ◽  
Author(s):  
DF Herridge
Keyword(s):  
N2 Fixation ◽  
Plant Size ◽  
Lupinus Angustifolius ◽  
Xylem Exudate ◽  
Plant Parts ◽  
Rooting Medium ◽  
Rhizobium Lupini ◽  
Nitrate Supply ◽  
Root Tissues ◽  
Rotation Crop

Experiments to develop indices of N2 fixation activity for the narrow-leafed lupin (Lupinus angustifolius L.) are reported. In Experiment 1 Unicrop narrow-leafed lupins were inoculated at sowing with effective Rhizobium lupini WU425. The conversion factor relating C2H2 reduction to N2 fixation was not constant throughout growth but increased from 0.9 (50-60 day period) to 6.6 (110-120 days). A nodulation index [(nodule wt/shoot wt) x 100], developed to account for plant size, declined with increasing nitrate supply and with increasing plant age. However, minor shifts in the nodulation index represented large shifts in plant dependence on N2 fixation (p), when plants were 60-100% dependent on N2 fixation. Concentrations of nitrate in extracts of the shoot axes and nodulated roots increased with increasing nitrate supply. Although the presence of nitrate in the rooting medium was evidenced by its presence in xylem exudate, the relationship between nitrate supply and the nitrate contents of xylem exudate was generally poor. Functions were developed to describe the relationships between the nodulation index and p, and between both shoot and root nitrate and p. Other experiments highlighted the synchrony of nitrate supply and its appearance in root tissues and the lack of diurnal fluctuations in nitrate concentrations of plant parts.

scholarly journals The Arabidopsis Nitrate Transporter NRT1.8 Functions in Nitrate Removal from the Xylem Sap and Mediates Cadmium Tolerance

2010 ◽  
Vol 22 (5) ◽  
pp. 1633-1646 ◽  
Author(s):  
Jian-Yong Li ◽  
Yan-Lei Fu ◽  
Sharon M. Pike ◽  
Juan Bao ◽  
Wang Tian ◽  
...  
Keyword(s):  
Nitrate Removal ◽  
Xylem Sap ◽  
Cadmium Tolerance ◽  
Nitrate Transporter

scholarly journals Changes to the proteome and targeted metabolites of xylem sap in Brassica oleracea in response to salt stress

2011 ◽  
Vol 34 (5) ◽  
pp. 821-836 ◽  
Author(s):  
N. FERNANDEZ-GARCIA ◽  
M. HERNANDEZ ◽  
J. CASADO-VELA ◽  
R. BRU ◽  
F. ELORTZA ◽  
...  
Keyword(s):  
Salt Stress ◽  
Brassica Oleracea ◽  
Xylem Sap

Effect of sowing time on the once-over harvest yield of broccoli cultivars in north-west Tasmania

1986 ◽  
Vol 26 (4) ◽  
pp. 497
Author(s):  
B Chung ◽  
HL Strickland
Keyword(s):  
Brassica Oleracea ◽  
West Coast ◽  
Continuous Production ◽  
Plant Size ◽  
Sowing Time ◽  
North West ◽  
Growing Period ◽  
The North ◽  
Brassica Oleracea L

The effect of sowing times between November and May on the maturity and once-over harvest yield of broccoli (Brassica oleracea L. var. italica Plenck) was studied on the north-west coast of Tasmania. Sowing times between November and January had little effect on the plant size and marketable spear yield of the cultivar Futura. However, delaying sowing from January to March reduced the plant size and marketable spear yield of 10 cultivars of different maturity types. The length of the growing period of all cultivars was increased for sowings after February. A continuous production of broccoli for once-over harvest can be maintained for March-August by a combination of cultivars and sowings from January to March. However, yields of less than 5 t/ha can be expected for the mid-May-August harvests compared with yields in excess of 10 t/ha for March and April harvests.

scholarly journals CuCO3-painted Containers and Root Pruning Affect Apple and Green Ash Root Growth and Cytokinin Levels

HortScience ◽  
1991 ◽  
Vol 26 (3) ◽  
pp. 242-244 ◽  
Author(s):  
Michael A. Arnold ◽  
Eric Young
Keyword(s):  
Root Growth ◽  
Xylem Sap ◽  
Zeatin Riboside ◽  
Root Pruning ◽  
Dry Matter Accumulation ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Root Tips ◽  
Root And Shoot Growth ◽  
Before And After

CuCO3 at 100 g·liter-1 in a paint carrier applied to interior container surfaces effectively prevented root deformation in container-grown Malus domestica Borkh. and Fraxinus pennsylvanica Marsh. seedlings. CuCO3 treatments nearly doubled the number of white unsuberized root tips in both species. CuCO3 treatment increased some measures of root and shoot growth before and after transplanting to larger untreated containers. Root pruning at transplanting tended to reduce root and shoot fresh and dry matter accumulation in F. pennsylvanica seedlings and shoot extension in M. domestica seedlings. In some cases, root pruning of M. domestics at transplanting from CuCO3-treated containers increased root growth compared to unpruned CuCO3-treated and untreated seedlings. Changes in growth induced by CuCO3 and root pruning were not related to changes in trans -zeatin riboside-like activity in the xylem sap of-apple.

In situ Biological Groundwater Denitrification: Concepts and Preliminary Field Tests

1988 ◽  
Vol 20 (3) ◽  
pp. 197-209 ◽  
Author(s):  
A. Mercado ◽  
M. Libhaber ◽  
M. I. M. Soares
Keyword(s):  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Small Diameter ◽  
Field Tests ◽  
Economic Feasibility ◽  
Injection Well ◽  
Nitrate Content ◽  
Injection Wells ◽  
Protection Measures

High nitrate concentration presents the main groundwater quality problem of the Israeli coastal aquifer which supplies 25% of the total water consumption of the country. In about 50% of the coastal wells nitrate concentration exceeds 45 mg/l and in 18% of the wells nitrate concentration is above the maximum permissible concentration of the new Israeli standard - 70 mg/l. Although several protection measures, mainly administrative, were introduced, their impact would be pronounced only after 1-3 decades, thus nitrate removal technologies should be introduced as a mid-term solution. Pilot plant experiments were conducted in order to develop, demonstrate and compare various in-situ schemes for nitrate removal from groundwater by biological denitrification. Activities were focused towards two schemes: (i) Denitrification in a dual purpose (recharge-pumping) well and (ii) Substrate injection through a battery of small diameter wells surrounding a central production well (the “Daisy” system). Experiments related to the first scheme indicate that, though nitrate content can be reduced almost to zero, its economic feasibility seems to be unfavorable because of operational difficulties and the apparent requirements for costly supplementary treatment. Experiments related to the “Daisy” scheme demonstrated a nitrate removal efficiency of approximately 10%. Considering the fact that only one injection well of the three drilled functioned properly, the above mentioned nitrate removal represents the efficiency of a single injection well. It is anticipated that further experiments with the “Daisy” system consisting of 5-6 injection wells would result in a significant nitrate reduction.

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