Nitrogen source effects on Al toxicity in nonmycorrhizal and mycorrhizal pitch pine (Pinus rigida) seedlings. II. Nitrate reduction and NO3− uptake

1990 ◽  
Vol 68 (12) ◽  
pp. 2653-2659 ◽  
Author(s):  
Jonathan R. Cumming
Keyword(s):  
Nitrogen Source ◽  
Nitrate Reduction ◽  
Al Toxicity ◽  
Pisolithus Tinctorius ◽  
Sand Culture ◽  
Root Tips ◽  
Pinus Rigida ◽  
Pine Seedlings ◽  
Pitch Pine ◽  
Nr Activity

Nitrogen source utilization, mediated by the ectomycorrhizal symbiont Pisolithus tinctorius, may modulate Al toxicity in pitch pine (Pinus rigida) seedlings. Nitrate reduction, occurring primarily in the roots of pitch pine seedlings, represents a critical metabolic pathway that may be directly sensitive to Al or indirectly affected by changes in NO3− availability associated with Al exposure or mycorrhizal infection. To investigate these possibilities, pitch pine seedlings were grown in sand culture with NO3−, NH4NO3, or NH4+ and exposed to 0 or 200 μM Al for 6 weeks. Foliar N concentrations, root nitrate reductase (NR) activity, and Al inhibition of NR activity were highly dependent on the proportion of NO3− of the nutrient solution. The association of Pisolithus tinctorius with seedling roots reduced both root and foliar NR activity compared with non-inoculated controls, suggesting that NO3− uptake and translocation to foliage was reduced by the symbiont. This was confirmed by using 36ClO3− to measure unidirectional plasma membrane NO3− fluxes. Mycorrhizal root tips absorbed 50% less NO3− than nonmycorrhizal root tips. Preferential use of NH4+ by ectomycorrhizal roots may thus result in reduced movement of Al into root tissue and amelioration of Al toxicity. Key words: Pinus rigida, ectomycorrhizae, aluminum toxicity, nitrogen source.

Nitrogen source effects on Al toxicity in nonmycorrhizal and mycorrhizal pitch pine (Pinus rigida) seedlings. I. Growth and nutrition

1990 ◽  
Vol 68 (12) ◽  
pp. 2644-2652 ◽  
Author(s):  
Jonathan R. Cumming ◽  
Leonard H. Weinstein
Keyword(s):  
Nitrogen Source ◽  
Critical Factor ◽  
Aluminium Toxicity ◽  
Ectomycorrhizal Fungus ◽  
Al Toxicity ◽  
Sand Culture ◽  
P Availability ◽  
Pinus Rigida ◽  
P Limitation ◽  
Pitch Pine

Previous studies indicated that the association of Pisolithus tinctorius with pitch pine (Pinus rigida) seedling roots prevented Al toxicity from developing when seedlings were exposed to 200 μM Al in sand culture. The ectomycorrhizal fungus reduced seedling Al uptake and maintained P nutrition when seedlings were cultured on one-quarter strength Johnson's solution containing 3.5 and 0.5 mM [Formula: see text] and [Formula: see text], respectively. To broaden the scope of these findings, nonmycorrhizal and mycorrhizal seedlings were grown on one-quarter strength Johnson's solution modified to contain [Formula: see text], NH4NO3, or [Formula: see text]. Seedlings were exposed to 0 or 200 μM Al for 6 weeks. Reductions in seedling height growth rate and final shoot weight in response to Al occurred in nonmycorrhizal seedlings grown with [Formula: see text]. Root weights were consistently reduced by Al under all N-source combinations. Increasing proportions of [Formula: see text], in the nutrient solution increased cation accumulation in roots and shoots and depressed tissue anion concentrations. The coprecipitation of Al and Pi in roots of Al-treated seedlings further limited P availability in this treatment. Mycorrhizal infection maintained growth and foliar P levels under Al exposure, suggesting that Al-induced P limitation was a critical factor in nonmycorrhizal seedlings grown on primarily [Formula: see text]-based nutrient solutions. Key words: Pinus rigida, ectomycorrhizal, aluminium toxicity, nitrogen source.

scholarly journals Accumulation and localization of aluminium in root tips of loblolly pine seedlings and the associated ectomycorrhiza Pisolithus tinctorius

2005 ◽  
Vol 28 (2) ◽  
pp. 111-120 ◽  
Author(s):  
K. MOYER-HENRY ◽  
I. SILVA ◽  
J. MACFALL ◽  
E. JOHANNES ◽  
N. ALLEN ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Pisolithus Tinctorius ◽  
Root Tips ◽  
Pine Seedlings

Contrasting modes of survival by jack and pitch pine at a common range limit

2002 ◽  
Vol 32 (9) ◽  
pp. 1662-1674 ◽  
Author(s):  
Michael S Greenwood ◽  
William H Livingston ◽  
Michael E Day ◽  
Shawn C Kenaley ◽  
Alan S White ◽  
...  
Keyword(s):  
Pinus Banksiana ◽  
Pollen Viability ◽  
Jack Pine ◽  
Range Limit ◽  
Acadia National Park ◽  
Pinus Rigida ◽  
Pine Seedlings ◽  
Pine Regeneration ◽  
Pitch Pine ◽  
Dry Conditions

Freezing tolerance, reproductive development, and seed germination of jack pine (Pinus banksiana Lamb.) and pitch pine (Pinus rigida Mill.) were compared in a small sympatric population in Acadia National Park in Maine, at the southern range limit of the former and the northern limit of the latter. Freezing tolerances of vegetative shoots and roots were similar for both species. Both species flower prolifically, and there was no evidence of differences in either pollen viability, cone survival, or proportion of viable seed (65–70% of the total). Regeneration success (established seedlings ranging from 1 to 13 years old) was similar overall for both species, but success by species varied greatly in some years. Jack pine regeneration was significantly associated with thinner soils, while pitch pine regeneration was associated with thicker soils in hollows. Jack pine seed germinated significantly faster than pitch pine seed, especially when day–night temperature was reduced. Pitch pine seedlings always exhibited a significantly higher shoot/root ratio than those of jack pine. The most northerly provenances of jack pine germinated significantly faster than those from the most southerly provenances. Jack pine also germinated at a significantly higher percentage than pitch pine in exposed granite sand. Thus relatively cool, dry conditions may favor establishment of jack pine seedlings, while pitch pine establishment may be favored in warmer, wetter conditions.

Characterizing Canopy Fuels to Predict Fire Behavior in Pitch Pine Stands

2007 ◽  
Vol 24 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Matthew J. Duveneck ◽  
William A. Patterson
Keyword(s):  
Fire Behavior ◽  
Small Diameter ◽  
Basal Area ◽  
Regression Equations ◽  
Crown Fire ◽  
Pinus Rigida ◽  
Canopy Fuels ◽  
Pitch Pine ◽  
Thinning Operations ◽  
Pine Stands

Abstract Destructive sampling of 31 pitch pine (Pinus rigida P. Mill) trees ranging in dbh from 2.7 to 42.5 cm and in height from 4.1 to 23.8 m provided a complete inventory of needles and small-diameter branch weights used to characterize canopy fuels to predict fire behavior in pitch pine stands. Regression equations using dbh as an independent variable predict canopy bulk density with an r2 > 0.93. The results provide managers with a method of evaluating the effectiveness of thinning operations in reducing crown fire potential in well-stocked stands. To demonstrate the application of the method, we calculated the wind speed (Crowning Index [CI]) needed to sustain an active crown fire in thinned and unthinned pitch pine stands in Montague, Massachusetts. Thinning to 2.8 m2/ha basal area increased the CI from 34 to 98 km/hour.

Ecological analyses of the northernmost population of pitch pine (Pinus rigida)

1997 ◽  
Vol 27 (9) ◽  
pp. 1342-1350 ◽  
Author(s):  
A Meilleur ◽  
J Brisson ◽  
A Bouchard
Keyword(s):  
Pinus Rigida ◽  
Pitch Pine

scholarly journals Importance of Mineral Nutrition for Mitigating Aluminum Toxicity in Plants on Acidic Soils: Current Status and Opportunities

2018 ◽  
Vol 19 (10) ◽  
pp. 3073 ◽  
Author(s):  
Md. Rahman ◽  
Sang-Hoon Lee ◽  
Hee Ji ◽  
Ahmad Kabir ◽  
Chris Jones ◽  
...  
Keyword(s):  
Plant Growth ◽  
Mineral Nutrition ◽  
Aluminum Toxicity ◽  
Low Cost ◽  
Acid Soils ◽  
Cost Effective ◽  
Al Toxicity ◽  
Current Status ◽  
Root Tips ◽  
Acidic Soils

Aluminum (Al) toxicity is one of the major limitations that inhibit plant growth and development in acidic soils. In acidic soils (pH < 5.0), phototoxic-aluminum (Al3+) rapidly inhibits root growth, and subsequently affects water and nutrient uptake in plants. This review updates the existing knowledge concerning the role of mineral nutrition for alleviating Al toxicity in plants to acid soils. Here, we explored phosphorus (P) is more beneficial in plants under P-deficient, and Al toxic conditions. Exogenous P addition increased root respiration, plant growth, chlorophyll content, and dry matter yield. Calcium (Ca) amendment (liming) is effective for correcting soil acidity, and for alleviating Al toxicity. Magnesium (Mg) is able to prevent Al migration through the cytosolic plasma membrane in root tips. Sulfur (S) is recognized as a versatile element that alleviates several metals toxicity including Al. Moreover, silicon (Si), and other components such as industrial byproducts, hormones, organic acids, polyamines, biofertilizers, and biochars played promising roles for mitigating Al toxicity in plants. Furthermore, this review provides a comprehensive understanding of several new methods and low-cost effective strategies relevant to the exogenous application of mineral nutrition on Al toxicity mitigation. This information would be effective for further improvement of crop plants in acid soils.

Differential Response of Ajuga (Ajuga reptans), Wintercreeper (Euonymus fortunei), and Dwarf Burning Bush (Euonymus alatus‘Compacta’) to Root- and Shoot-Applied Isoxaben

1999 ◽  
Vol 13 (4) ◽  
pp. 685-690 ◽  
Author(s):  
Sydha Salihu ◽  
Jeffrey F. Derr ◽  
Kriton K. Hatzios
Keyword(s):  
Shoot Growth ◽  
Sand Culture ◽  
Root Weight ◽  
Root Tips ◽  
Visible Injury ◽  
Culture Studies ◽  
Ajuga Reptans ◽  
Euonymus Fortunei ◽  
Shoot Weight ◽  
Root Treatment

Hydroponics and sand culture studies evaluated the effects of isoxaben rate (0.84, 1.69, and 3.39 kg/ha) and application type (root only, shoot only, and root plus shoot) on the growth of ajuga, wintercreeper, and dwarf burning bush. Similar responses were exhibited by the three species tested in both hydroponics and sand culture studies. Based on shoot weight reductions, dwarf burning bush was one to three times more sensitive than wintercreeper, which was the most tolerant of the three species, and ajuga was five to 20 times more sensitive than wintercreeper. Isoxaben applied to the root system at all three rates injured ajuga root tips and foliage and reduced root weight by approximately 40% and shoot weight by 20 to 30%. Isoxaben applications to ajuga foliage damaged the roots and leaves and caused over 30% reductions in shoot and root weights at the highest rate tested. Isoxaben applied to dwarf burning bush roots caused less than 20% shoot injury, reduced root weight by 8 to 18%, and reduced shoot weight by less than 10%. Application to dwarf burning bush foliage caused 20 to 30% injury, but only slight reductions in root and shoot weights were observed. No visible injury was observed in wintercreeper from any isoxaben application. However, root treatment reduced wintercreeper root weight by approximately 15%, and shoot treatment reduced shoot weight by 6 to 10% at the highest isoxaben rate tested. Application of isoxaben to both roots and foliage of wintercreeper resulted in similar reductions in shoot and root weights compared to root or shoot exposure alone. Shoot application to wintercreeper affected root growth, and root treatment reduced shoot growth.

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