scholarly journals STUDY OF THE PHTHALATES COMPOSITION IN THE PEA SEEDLINGS ROOT EXUDATES INOCULATED WITH RHIZOBIUM LEGUMINOSARUM BV. VICEAE AND PSEUDOMONAS SYRINGAE PV. PISI AT DIFFERENT TEMPERATURES

2018 ◽  
Author(s):  
L.E. Makarova ◽  
A.S. Morits ◽  
N.A. Sokolova ◽  
I.S. Nesterkina
Keyword(s):  
Pseudomonas Syringae ◽  
Root Exudates ◽  
Rhizobium Leguminosarum ◽  
Pea Seedlings ◽  
Different Temperatures

Influence of Temperature and Plant Growth Stages of Red Clover and Wheat on Small Broomrape (Orobanche minor) Germination

2014 ◽  
Vol 28 (1) ◽  
pp. 266-271 ◽  
Author(s):  
Salam A. Al-Thahabi ◽  
Jed B. Colquhoun ◽  
Carol A. Mallory-Smith
Keyword(s):  
Seed Germination ◽  
Root Exudates ◽  
Integrated Management ◽  
Red Clover ◽  
Wheat Root ◽  
Management Plan ◽  
Growth Stages ◽  
Plant Growth Stages ◽  
Different Temperatures ◽  
Infested Field

Small broomrape is a holoparasitic plant that attaches to the roots of red clover as well as several other host plants. Hosts and false hosts produce stimulants that induce small broomrape germination but small broomrape does not attach to a false host. Wheat has been identified as a false host for small broomrape; therefore, studies were conducted to investigate the effect of red clover and wheat root exudates on small broomrape germination. In one study, the effect of exudates from red clover and wheat at multiple growth stages on small broomrape germination was evaluated. Red clover induced small broomrape germination at all growth stages tested but was greatest (78%) in the presence of exudates from red clover at the three-trifoliolate stage. Maximum small broomrape germination was 25% when exposed to exudates produced by one-leaf-stage wheat. In a second study, the relationship between small broomrape germination and host growth condition was evaluated using root exudates from red clover or wheat grown under several temperature conditions for either 4 or 8 wk. For the different temperatures, there were no differences in small broomrape germination when exudates of red clover grown for 4 wk were used. Small broomrape germination was reduced when exposed to exudates from red clover plants grown for 8 wk at 10 C compared with plants grown at 15, 20, and 25 C. Differences in small broomrape seed germination were observed with temperature under which wheat was grown for 4 wk, but not for 8 wk. Although wheat exudates resulted in less small broomrape seed germination than red clover exudates, growing wheat as a false host in a small broomrape-infested field could be an important component of an integrated management plan.

Detection of Pseudomonas syringae pv. Savastanoi, causal agent of olive tuberculosis in two regions of Western Algeria (Ain Témouchent and Sig)

2019 ◽  
Vol 9 (2) ◽  
pp. 64-71
Author(s):  
Benyoub Kheira ◽  
Kacem Mourad ◽  
Kaid-Harche Meriem
Keyword(s):  
Pseudomonas Syringae ◽  
Olive Tree ◽  
Causal Agent ◽  
Biochemical Tests ◽  
Node Disease ◽  
Different Temperatures ◽  
Leaf Level ◽  
Western Algeria ◽  
Olive Trees ◽  
Tree Leaf

The present study on olive tuberculosis commenced by isolating bacteria of the genus Pseudomonas from the soils and necrosis of collected olive trees. A total of 180 samples were used in this study: (100) rhizospheric soil samples: (60) samples at the region of Ain Témouchent and (40) at the region of Sig in western of Algeria. In total, (80) galls were collected (40) at branch level and (40) galls at olive tree leaf (level). The isolates were identified by microbiological (macroscopic and microscopic examination), physiological (growth in the presence of Salt (NaCl), growth at different pH values and growth at different temperatures) and biochemical methods (the LOPAT and Galeries Api 20 NE test to identify species of the Pseudomonas group and conventional biochemical tests to identify the subspecies P. syringae pv. Savastanoi).This allowed to identify 110 isolates of Pseudomonas (60 isolates of P. aeruginosa, 35 isolates of P. fluorescens and 15 isolates of P. syringae pv Savastanoi the causal agent of olive node disease) which are now part of the collection of Pseudomonas bacteria of the laboratory of the Biotechnology Department (USTO-MB). The selection of technological performance isolates useful for our agriculture could solve phytopathological problems and finally constitute a collection of the bacteria preserved.

scholarly journals Comparison of Characteristics of the nodX Genes from Various Rhizobium leguminosarum Strains

1999 ◽  
Vol 12 (3) ◽  
pp. 252-258 ◽  
Author(s):  
Alexandra O. Ovtsyna ◽  
Geert-Jan Rademaker ◽  
Edwin Esser ◽  
Jeremy Weinman ◽  
Barry G. Rolfe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Structural Analysis ◽  
Root Exudates ◽  
Rhizobium Leguminosarum ◽  
Nucleotide Sequences ◽  
Phenotypic Differences ◽  
Pea Root

We have analyzed the nucleotide sequences of the nodX genes from two strains of Rhizobium leguminosarum bv. viciae able to nodulate Afghan peas (strains A1 and Himalaya) and from two strains of R. leguminosarum bv. trifolii (ANU843 and CSF). The nodX genes of strains A1 and ANU843 were shown to be functional for the induction of nodules on Afghan peas. To analyze the cause of phenotypic differences of strain A1 and strain TOM we have studied the composition of the lipochitin-oligosaccharides (LCOs) produced by strain A1 after induction by the flavonoid naringenin or various pea root exudates. The structural analysis of the LCOs by mass spectrometry revealed that strain A1 synthesizes a family of at least 23 different LCOs. The use of exudates instead of naringenin resulted only in quantitative differences in the ratios of various LCOs produced.

Rhizobium Inoculation Induces Condition-Dependent Changes in the Flavonoid Composition of Root Exudates From Trifolium subterraneum

1996 ◽  
Vol 23 (1) ◽  
pp. 93 ◽  
Author(s):  
CGR Lawson ◽  
BG Rolfe ◽  
MA Djordjevic
Keyword(s):  
Gene Expression ◽  
Root Exudates ◽  
Rhizobium Leguminosarum ◽  
Light Exposure ◽  
Trifolium Subterraneum ◽  
Rhizobium Inoculation ◽  
Rapid Induction ◽  
Hplc Profiles ◽  
Microbe Interactions ◽  
Root Tissues

Rapid induction of chalcone synthase (predominantly CHSS) gene expression occurs within 6 h following the inoculation of Rhizobium leguminosarum bv. trifolii strain ANU843 on Trifolium subterraneum or wounding of plants (C. G. R. Lawson, M. A. Djordjevic, J. J. Weinman and B. G. Rolfe. 1994. Molecular Plant-Microbe Interactions 7, 498-507). Experiments were conducted under the same conditions to examine the time of onset of synthesis and excretion of flavonoids that might result from this early CHS expression. Flavonoids in root tissues and root exudates were examined by HPLC analysis and the ability of fractionated and unfractionated material to induce nodulation gene expression in Rhizobium measured. There were no detectable changes in nod-gene-inducing activity of individual HPLC fractions of root exudates of 1 day dark-grown roots after Rhizobium inoculation. In contrast, after 3 days exposure to Rhizobium, analysis of specific HPLC fractions showed the presence of an additional nod-gene-inducing compound which the data indicate was 4′,7-dihydroxyflavone. A different and additional nod gene inducer was found in inoculated 5 day samples of root exudate of light-grown plants indicating that light exposure changes the HPLC profiles as well as the nod-gene-inducing compound(s). Exudates collected from wounded plants were considerably different from those from Rhizobium-inoculated and uninoculated plants and contained no detectable nod gene inducers. The late detection (at day 3) of Rhizobium-induced flavonoid excretion may occur too late to be directly correlated with the observed expression of CHS 6 h after inoculation. In addition, the data suggest that although the CHS5 promotor responds to both wounding and Rhizobium inoculation, the biochemical consequences of CHS5 induction resulting from these treatments are different.

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