EFFECT OF MOLYBDENUM APPLICATIONS ON LEGUMINOUS HAY CROPS IN PRINCE EDWARD ISLAND

1957 ◽  
Vol 37 (3) ◽  
pp. 193-195 ◽  
Author(s):  
D. B. Robinson ◽  
K. E. LeLacheur ◽  
G. A. Brossard
Keyword(s):  
Soil Type ◽  
Prince Edward Island ◽  
Root Nodule ◽  
Root Nodules ◽  
Red Clover ◽  
Soil Types ◽  
Nodule Formation ◽  
Root Nodule Formation ◽  
Clover Root ◽  
Better Than

Seed treatments of molybdenum were found to increase yields of early red clover on three soil types in Prince Edward Island. Plots receiving 8 or more ounces of molybdenum per acre were significantly better than the control plots. Applications of 1000 lb. and 2000 lb. of ground limestone per acre had no effect on the yields of molybdenum-treated clover but the uptake of molybdenum by plants was highest where the 2000 lb.-per-acre rate was applied. The influence of added molybdenum on clover root nodule formation was determined on one soil type. Eight ounces of molybdenum per acre gave a significant increase in the weight of root nodules on the treated plants.

scholarly journals FrankiaDiversity in Host Plant Root Nodules Is Independent of Abundance or Relative Diversity ofFrankiaPopulations in Corresponding Rhizosphere Soils

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Seifeddine Ben Tekaya ◽  
Trina Guerra ◽  
David Rodriguez ◽  
Jeffrey O. Dawson ◽  
Dittmar Hahn
Keyword(s):  
Host Plant ◽  
Root Nodule ◽  
Root Nodules ◽  
Actinorhizal Plants ◽  
Nodule Formation ◽  
Nitrogen Fixing ◽  
Content Type ◽  
Rhizosphere Soils ◽  
Root Nodule Formation ◽  
Host Infection

ABSTRACTActinorhizal plants form nitrogen-fixing root nodules in symbiosis with soil-dwelling actinobacteria within the genusFrankia, and specificFrankiataxonomic clusters nodulate plants in corresponding host infection groups. In same-soil microcosms, we observed that some host species were nodulated (Alnus glutinosa,Alnus cordata,Shepherdia argentea,Casuarina equisetifolia) while others were not (Alnus viridis,Hippophaë rhamnoides). Nodule populations were represented by eight different sequences ofnifHgene fragments. Two of these sequences characterized frankiae inS. argenteanodules, and three others characterized frankiae inA. glutinosanodules. Frankiae inA. cordatanodules were represented by five sequences, one of which was also found in nodules fromA. glutinosaandC. equisetifolia, while another was detected in nodules fromA. glutinosa. Quantitative PCR assays showed that vegetation generally increased the abundance of frankiae in soil, independently of the target gene (i.e.,nifHor the 23S rRNA gene). Targeted Illumina sequencing ofFrankia-specificnifHgene fragments detected 24 unique sequences from rhizosphere soils, 4 of which were also found in nodules, while the remaining 4 sequences in nodules were not found in soils. Seven of the 24 sequences from soils represented >90% of the reads obtained in most samples; the 2 most abundant sequences from soils were not found in root nodules, and only 2 of the sequences from soils were detected in nodules. These results demonstrate large differences between detectableFrankiapopulations in soil and those in root nodules, suggesting that root nodule formation is not a function of the abundance or relative diversity of specificFrankiapopulations in soils.IMPORTANCEThe nitrogen-fixing actinobacteriumFrankiaforms root nodules on actinorhizal plants, with members of specificFrankiataxonomic clusters nodulating plants in corresponding host infection groups. We assessedFrankiadiversity in root nodules of different host plant species, and we related specific populations to the abundance and relative distribution of indigenous frankiae in rhizosphere soils. Large differences were observed between detectableFrankiapopulations in soil and those in root nodules, suggesting that root nodule formation is not a function of the abundance or relative diversity of specificFrankiapopulations in soils but rather results from plants potentially selecting frankiae from the soil for root nodule formation. These data also highlight the necessity of using a combination of different assessment tools so as to adequately address methodological constraints that could produce contradictory data sets.

scholarly journals Autoregulation of Root Nodule Formation: Signals of Both Symbiotic Partners Studied in a Split-Root System of Vicia sativa subsp. nigra

2002 ◽  
Vol 15 (4) ◽  
pp. 341-349 ◽  
Author(s):  
Anton A. N. van Brussel ◽  
Teun Tak ◽  
Kees J. M. Boot ◽  
Jan W. Kijne
Keyword(s):  
Rhizobium Leguminosarum ◽  
Root Nodule ◽  
Root Nodules ◽  
Nodule Formation ◽  
Vicia Sativa ◽  
Nod Factors ◽  
Split Root ◽  
Split Root System ◽  
Root Nodule Formation ◽  
Plant Signals

Inhibition of root nodule formation on leguminous plants by already induced or existing root nodules is called autoregulation of root nodule formation (AUT). Optimal conditions for AUT were determined using a split-root technique newly developed for Vicia sativa subsp. nigra. Infection of a root A with nodulating Rhizobium leguminosarum bv. viciae bacteria systemically inhibited nodulation of a spatially separated root B inoculated 2 days later with the same bacteria. This treatment gives complete AUT (total absence of nodules on root B). Only partial AUT of root B was obtained by incubation of root A with mitogenic nodulation (Nod) factors or with a noninfective strain producing normal mitogenic Nod factors. Nonmitogenic Nod factors did not evoke AUT. We identified two systemic plant signals induced by Rhizobium bacteria. Signal 1 (at weak buffering) was correlated with sink formation in root A and induced acidification of B-root medium. This signal is induced by treatment of root A with (i) nodulating rhizobia, (ii) mitogenic Nod factors, (iii) nonmitogenic Nod factors, or (iv) the cytokinin zeatin. Signal 2 (at strong buffering) could only be evoked by treatment with nodulating rhizobia or with mitogenic Nod factors. Most probably, this signal represents the specific AUT signal. Induction of complete AUT appears to require actively dividing nodule cells in nodule primordia, nodule meristems, or both of root A.

Root Nodule Formation on the Garden Bean, Studied by a Technique of Tissue Culture

1933 ◽  
Vol 95 (2) ◽  
pp. 316-329 ◽  
Author(s):  
Keith H. Lewis ◽  
Elizabeth McCoy
Keyword(s):  
Tissue Culture ◽  
Root Nodule ◽  
Nodule Formation ◽  
Root Nodule Formation

Inheritance and Expression of Three Genes Controlling Root Nodule Formation in Chickpea 1

Crop Science ◽  
1986 ◽  
Vol 26 (4) ◽  
pp. 719-723 ◽  
Author(s):  
Thomas M. Davis ◽  
K. W. Foster ◽  
Donald A. Phillips
Keyword(s):  
Root Nodule ◽  
Nodule Formation ◽  
Root Nodule Formation

scholarly journals The Biology of Frankia sp. Strains in the Post-Genome Era

2011 ◽  
Vol 24 (11) ◽  
pp. 1310-1316 ◽  
Author(s):  
David R. Benson ◽  
James M. Brooks ◽  
Ying Huang ◽  
Derek M. Bickhart ◽  
Juliana E. Mastronunzio
Keyword(s):  
Root Nodule ◽  
Root Nodules ◽  
Ammonium Assimilation ◽  
Defense Responses ◽  
Nodule Formation ◽  
Plant Defense Responses ◽  
Plant Host ◽  
Future Studies ◽  
Microbiological Techniques ◽  
Bacterial Genes

Progress in understanding symbiotic determinants involved in the N2-fixing actinorhizal plant symbioses has been slow but steady. Problems persist with studying the bacterial contributions to the symbiosis using traditional microbiological techniques. However, recent years have seen the emergence of several genomes from Frankia sp. strains and the development of techniques for manipulating plant gene expression. Approaches to understanding the bacterial side of the symbiosis have employed a range of techniques that reveal the proteomes and transcriptomes from both cultured and symbiotic frankiae. The picture beginning to emerge provides some perspective on the heterogeneity of frankial populations in both conditions. In general, frankial populations in root nodules seem to maintain a rather robust metabolism that includes nitrogen fixation and substantial biosynthesis and energy-generating pathways, along with a modified ammonium assimilation program. To date, particular bacterial genes have not been implicated in root nodule formation but some hypotheses are emerging with regard to how the plant and microorganism manage to coexist. In particular, frankiae seem to present a nonpathogenic presence to the plant that may have the effect of minimizing some plant defense responses. Future studies using high-throughput approaches will likely clarify the range of bacterial responses to symbiosis that will need to be understood in light of the more rapidly advancing work on the plant host.

Sign in / Sign up

Export Citation Format

Share Document