On tripartite Frankia–mycorrhizal associations in the Myricaceae

1989 ◽  
Vol 67 (6) ◽  
pp. 1708-1712 ◽  
Author(s):  
Ruhama Berliner ◽  
John G. Torrey
Keyword(s):  
Forest Soils ◽  
Root Formation ◽  
Nitrogenase Activity ◽  
Mycorrhizal Fungus ◽  
Sand Culture ◽  
Mineral Nutrient ◽  
Cluster Roots ◽  
Native Forest ◽  
Natural Habitats ◽  
Cluster Root

Actinomycorrhizal symbiosis was studied in Comptonia peregrina (L.) Coult. and in Myrica gale L., both of the Myricaceae. Root nodules were common in all Comptonia plants in their natural habitats and in pot cultures under greenhouse conditions. Spontaneous actinorhizal infection under greenhouse conditions differed in two native forest soils. Spontaneous mycorrhizal infection in C. peregrina and in M. gale was found neither in natural habitats nor in plants growing in native forest soils under greenhouse conditions. Comptonia peregrina and M. gale inoculated with the actinomycete Frankia, with the vesicular–arbuscular mycorrhizal fungus Glomus intraradices, or with Frankia and G. intraradices together were infected by Frankia only. The nodulated plants were significantly larger compared with unnodulated plants, and their root systems showed acetylene reduction in a bioassay for nitrogenase activity. Uninfected Comptonia plants that grew in a forest soil under greenhouse conditions developed well when watered with a complete mineral nutrient solution or with a solution that lacked phosphorus, but degenerated when watered with a solution that lacked combined nitrogen or with deionized water. Comptonia peregrina and M. gale formed cluster roots that resembled proteoid roots in the Proteaceae. In Comptonia, cluster-root formation in sand culture was common in nodulated plants as well as in unnodulated plants. In M. gale, cluster-root formation was common in nodulated plants and infrequent in unnodulated plants.

Cluster root formation by Gymnostoma papuanum (Casuarinaceae) in relation to aeration and mineral nutrient availability in water culture

1990 ◽  
Vol 68 (12) ◽  
pp. 2564-2570 ◽  
Author(s):  
Suzanne Racette ◽  
Isabelle Louis ◽  
John G. Torrey
Keyword(s):  
Root Growth ◽  
Root Formation ◽  
Phosphorus Deficiency ◽  
Lateral Roots ◽  
Critical Factor ◽  
Mineral Nutrient ◽  
Cluster Roots ◽  
Phosphorus Level ◽  
Water Culture ◽  
Cluster Root

The term cluster root is used to refer to a dense cluster of determinate lateral roots (rootlets), in preference to the terms proteoid root and proteoid-like root used by other authors. Cluster roots are often formed by the actinorhizal plant Gymnostoma papuanum. In water culture, cluster root formation by G. papuanum was influenced by aeration, phosphorus level, and nitrogen source. Aeration was a critical factor, with nonaerated rooted cuttings having far fewer cluster roots than aerated ones. Phosphorus deficiency was the single nutrient deficiency that led to increased cluster root formation. Seedlings, grown under conditions of either low (0.8 mg∙L−1) or no phosphorus, responded by devoting a greater portion of root growth to the production of cluster roots, with no overall reduction in root growth for 6 weeks. The response to varying phosphorus level was modified by providing nitrogen in different forms. Supplying nitrogen as ammonium resulted in low levels of cluster root formation. Supplying nitrate to nodulated seedlings led to an increase in cluster root formation in comparison with plants that depended solely upon dinitrogen fixation by Frankia. Greatest cluster root formation occurred on plants grown in aerated water cultures supplied with nitrate and with little or no phosphorus. Key words: Gymnostoma papuanum, cluster roots, proteoid roots, phosphorus deficiency.

scholarly journals Ecophysiological properties of a cluster root-forming plant, Helicia cochinchinensis (Proteaceae) grown on Miyajima Island, Japan

2022 ◽  
Author(s):  
Jun Wasaki ◽  
Tadashi Okamura ◽  
Taiki Yamauchi ◽  
Hayato Maruyama ◽  
Shinji Uchida ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Root Exudates ◽  
Root Formation ◽  
P Uptake ◽  
Cluster Roots ◽  
Organic P ◽  
Cluster Root ◽  
Olsen P ◽  
The Family ◽  
Senesced Leaves

Abstract Aims The family Proteaceae is one of the dominant families in nutrient-impoverished habitats in the Southern hemisphere, and less common in the Northern hemisphere. Helicia cochinchinensis Lour. is the only Proteaceae species in Japan. This study aimed to unveil the ecophysiological properties of H. cochinchinensis grown on Miyajima Island, Hiroshima, Japan.Methods Phosphorus (P) status and dynamics of soils in H. cochinchinensis habitats were measured. Plant P and nitrogen (N) concentrations of leaves were measured after digestion. Roots and rhizosheath soil were collected to assess root morphology and root exudates.Results Available P (Olsen-P) in soils in habitats of H. cochinchinensis was 0.46–3.7 mg P kg-1 soil. Citrate was the major carboxylate in root exudates and its concentration increased during cluster-root formation. Acid phosphatase activity was greater at the surface of cluster roots that on the surface of other roots and bulk soil, especially for mature cluster roots. Sparingly soluble organic P concentrations decreased in the rhizosheath soil of mature cluster roots. The P concentrations of H. cochinchinensis leaves were relatively low; 0.34–0.69 mg P g-1 DW and 0.15–0.29 mg P g-1 DW in mature and senesced leaves, respectively. The P demand of H. cochinchinensis was less than that of nearby trees, showing greater P-remobilization efficiency.Conclusions Phosphorus mobilization from unavailable P by cluster roots supported P uptake by H. cochinchinensis, and P remobilization from senescing leaves contributed to sustain growth under P-deficient conditions.

Cluster Roots and Mycorrhizae in Casuarina cunninghamiana: their Occurrence and Formation in Relation to Phosphorus Supply

1997 ◽  
Vol 45 (1) ◽  
pp. 41 ◽  
Author(s):  
Paul Reddell ◽  
Yang Yun ◽  
Warren A. Shipton
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Mycorrhizal Fungus ◽  
Natural Populations ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Solution Culture ◽  
Sand Culture ◽  
Cluster Roots ◽  
Casuarina Cunninghamiana ◽  
P Supply

The occurrence of mycorrhizae and cluster roots was assessed in natural populations of Casuarina cunninghamiana Miq. in north Queensland. Cluster roots were found at 90% of the sites surveyed. By contrast, arbuscular mycorrhizae occurred at only 45% of sites and the extent of colonisation was low. No ectomycorrhizae were found during this survey. Formation of arbuscular mycorrhizae and cluster roots in C. cunninghamiana seedlings in relation to external P supply was investigated in glasshouse experiments. Inoculation with the arbuscular mycorrhizal fungus, Glomus, significantly increased seedling dry weight at low P supply (10 mg P per kg soil), but had no effect in the absence of P or at P supply rates greater than 10 mg P per kg soil. Mycorrhizal colonisation of roots was highest at 0 and 10 mg P per kg soil and declined with further increases in P supply. No mycorrhizae formed at or above 100 mg P per kg soil. The number, dry weight and proportion of root biomass allocated to cluster roots in solution culture decreased with increasing P supply, and followed a generally similar pattern to that observed for arbuscular mycorrhizae in sand culture. No cluster roots formed at P supply of 100 µM P or higher, and the form of nitrogen available to the plant (either adequate supply of mineral nitrogen or dependency on symbiotic N2 fixation) had no effect on cluster root formation at any level of P supply. Casuarina cunninghamiana occurs naturally along stream and river banks and cluster roots may be advantageous at these sites by providing a reliable mechanism to enhance nutrient uptake in seasonally inundated environments that are unlikely to be favourable to mycorrhizal formation and activity.

scholarly journals Nodulated White Lupin Plants Growing in Contaminated Soils Accumulate Unusually High Mercury Concentrations in Their Nodules, Roots and Especially Cluster Roots

Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 302
Author(s):  
Miguel A. Quiñones ◽  
Susana Fajardo ◽  
Mercedes Fernández-Pascual ◽  
M. Mercedes Lucas ◽  
José J. Pueyo
Keyword(s):  
Contaminated Soils ◽  
Lupinus Albus ◽  
White Lupin ◽  
Cluster Roots ◽  
Cluster Root ◽  
Bioaccumulation Factors ◽  
Aerial Parts ◽  
High Mercury ◽  
Lupinus Albus L ◽  
Hg Accumulation

Two white lupin (Lupinus albus L.) cultivars were tested for their capacity to accumulate mercury when grown in Hg-contaminated soils. Plants inoculated with a Bradyrhizobium canariense Hg-tolerant strain or non-inoculated were grown in two highly Hg-contaminated soils. All plants were nodulated and presented a large number of cluster roots. They accumulated up to 600 μg Hg g−1 DW in nodules, 1400 μg Hg g−1 DW in roots and 2550 μg Hg g−1 DW in cluster roots. Soil, and not cultivar or inoculation, was accountable for statistically significant differences. No Hg translocation to leaves or seeds took place. Inoculated L. albus cv. G1 plants were grown hydroponically under cluster root-promoting conditions in the presence of Hg. They accumulated about 500 μg Hg g−1 DW in nodules and roots and up to 1300 μg Hg g−1 DW in cluster roots. No translocation to the aerial parts occurred. Bioaccumulation factors were also extremely high, especially in soils and particularly in cluster roots. To our knowledge, Hg accumulation in cluster roots has not been reported to date. Our results suggest that inoculated white lupin might represent a powerful phytoremediation tool through rhizosequestration of Hg in contaminated soils. Potential uptake and immobilization mechanisms are discussed.

Influence of increasing soil phosphorus levels on interactions between vesicular–arbuscular mycorrhizae and Rhizobium in soybeans

1980 ◽  
Vol 58 (20) ◽  
pp. 2200-2205 ◽  
Author(s):  
S. Asimi ◽  
V. Gianinazzi-Pearson ◽  
S. Gianinazzi
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizae ◽  
Nitrogenase Activity ◽  
Mycorrhizal Fungus ◽  
Growth Stimulation ◽  
Growth And Yield ◽  
Nodule Formation ◽  
Growth Responses ◽  
Vesicular Arbuscular ◽  
Phosphate Fertilization

Growth and yield increases, obtained in nodulated soybeans growing in unamended sterile soil by inoculation with the vesicular–arbuscular (VA) mycorrhizal fungus Glomus mosseae, were accompanied by improved P uptake, lower root to shoot ratios, better nodulation with higher nitrogenase activity, and modifications in the pattern of the latter during plant growth. Stimulation of nitrogenase activity occurred early in plant development and preceded plant growth responses by about 2 weeks. Phosphate fertilization increased yield, percent P but not percent N of both mycorrhizal and nonmycorrhizal soybeans, and also modified the pattern and amount of nitrogenase activity during plant growth. Additions of 0.25 g KH2PO4/kg to the soil eliminated the mycorrhizal effect on plant growth, but nodule formation and nitrogenase activity were still significantly stimulated by the mycorrhizal infection. Mycorrhizal effects on nodulation were eliminated with 0.5 g KH2PO4 and on nitrogenase activity with the addition of 1.0 g KH2PO4. These higher levels of phosphate fertilization considerably diminished infection and, in particular, fungal spread within the roots.

scholarly journals Update on White Lupin Cluster Root Acclimation to Phosphorus Deficiency Update on Lupin Cluster Roots

2011 ◽  
Vol 156 (3) ◽  
pp. 1025-1032 ◽  
Author(s):  
Lingyun Cheng ◽  
Bruna Bucciarelli ◽  
Jianbo Shen ◽  
Deborah Allan ◽  
Carroll P. Vance
Keyword(s):  
Phosphorus Deficiency ◽  
White Lupin ◽  
Cluster Roots ◽  
Cluster Root

A comparison of growth responses of Douglas fir and Sitka spruce to different nitrogen, phosphorus, and potassium levels in sand culture

1968 ◽  
Vol 46 (5) ◽  
pp. 531-537 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Weight Ratio ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Response To Treatment ◽  
Sand Culture ◽  
Mineral Nutrient ◽  
Growth Responses ◽  
Net Assimilation ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

Douglas fir and Sitka spruce seedlings were grown in sand culture under controlled mineral nutrient conditions. Nitrogen, phosphorus, and potassium supply levels were varied one nutrient at a time in three separate experiments. The relative growth rate (RGR) of Sitka spruce was found to be higher than that of Douglas fir at high levels of N and K supply, although in all treatments the total dry matter production of Douglas fir was greater than that of Sitka spruce after 95 days. At low levels of P supply the RGR of Douglas fir was greater than that of Sitka spruce.Effects of treatment on RGR were apparently achieved mainly by their effect on net assimilation rate, but leaf weight ratio also showed a small, and significant, response to treatment.

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