Sur la nutrition aminée de Corynebacterium sepedonicum (Spieck. et Kott.) Skapt. et Burkh. et la résistance de la pomme de terre au flétrissement bactérien

1970 ◽  
Vol 16 (8) ◽  
pp. 719-726 ◽  
Author(s):  
Roger Paquin ◽  
Robert A. Lachance

Corynebacterium sepedonicum can grow in a medium containing only two amino acids: asparagine and methionine as sources of nitrogen. In the presence of cystine, γ-aminobutyric acid, β-alanine, glycine, and ethanolamine, the growth of the organism was inhibited or retarded. Even in the presence of casein hydrolysate, cystine inhibits the bacterial growth. The presence of cystine and certain other amino acids in the tissues of potatoes could, in part, explain the slow growth of the organism in the host tissues, the late appearance of the potato ring rot symptoms, and the resistance of certain potato varieties to ring rot.

1978 ◽  
Vol 24 (9) ◽  
pp. 1087-1092
Author(s):  
G. J. Ikin ◽  
H. J. Hope ◽  
R. A. Lachance

Some aspects of the growth and amino acid metabolism of Corynebacterium sepedonicum, the organism responsible for potato ring rot, have been studied in synthetic media. It has been demonstrated that organic sulfur is required for growth. Methionine supports growth and can be replaced by methionine sulfoxide and cystathionine. Methionine is a micrometabolite for this species as indicated by the fact that optimum growth can be obtained in an asparagines–methionine (asn-met) containing medium when the molar ratio of these amino acids is 56:1. Increasing the proportion of methionine does not increase the growth. Both asparagine and glutamine are metabolized very quickly and provide for equivalent rapid growth unlike aspartic and glutamic acids. In the case of the last two amino acids, growth can be increased if dibasic ammonium phosphate is added to the medium although this compound alone will not support growth in the culture medium. The intracellular soluble asparagine level is extremely low in cells from the asn-met medium indicating a high rate of metabolism compared to aspartic acid. Cystine and cysteine were found to be inhibitory to the organism: they do not affect the rate of uptake of asn or met but do alter the organism's metabolism as reflected by changes in the free amino acid pool. The concentrations of cystine and cysteine required for measurable inhibition are much higher than those found in soluble amino acids of potato tubers.


1961 ◽  
Vol 7 (2) ◽  
pp. 185-188 ◽  
Author(s):  
J. F. T. Spencer ◽  
P. A. J. Gorin

Corynebacterium insidiosum and Corynebacterium sepedonicum, the causative agents of bacterial wilt of alfalfa and of potato ring rot, produce viscous polysaccharide solutions when grown in shaken culture. These substances contain fucose, a sugar rarely found in polysaccharides of land plants. Hydrolyzates of polysaccharides extracted from alfalfa and potato plants infected with these organisms also contained fucose, while extracts of healthy plants did not. Alfalfa cuttings placed in dilute polysaccharide solutions wilted rapidly. These findings suggest that these polysaccharides are probably formed in the vascular systems of infected plants and that if such is the case they contribute to the development of the disease in these plants.


1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.


1972 ◽  
Vol 50 (4) ◽  
pp. 803-818 ◽  
Author(s):  
Hans E. Gruen ◽  
Sheue-heng Wu

Isolated Flammulina velutipes fruit bodies were cultured under sterile conditions with the cut base immersed in water or solutions. Stipe elongation on water was only 6% of normal for fruit bodies isolated at 1.1–2.0 cm length, 19% at 5.1–6.0 cm, and the same as for fruit bodies attached to mycelium at 9.1–10.0 cm. Fruit bodies not immersed in water grew less in a saturated atmosphere than those in water. The mycelium must supply other substances than water for normal elongation during about two-thirds of the growth period, and only water thereafter. Isolated fruit bodies fed with filtered glucose, trehalose, sucrose, or mannitol grew better than on water. Maltose and fructose increased elongation only slightly, and sorbose had no effect. Potato extract, yeast extract, and casein hydrolysate gave no or very little growth promotion, but addition of glucose strongly increased growth on the natural extracts compared to glucose alone. Of 21 amino acids added separately to glucose, only asparagine, hydroxyproline, arginine, and to a lesser extent glutamine, stimulated growth of isolated fruit bodies. Growth was not promoted by pure asparagine, glutamine, and serine, or by thiamin or indoleacetic acid. Growth was inhibited by urea, ammonium nitrate, and ammonium tartrate with or without glucose.Growth promoting substances were most effective in young fruit bodies and except for glucose the promotion disappeared in fruit bodies isolated at 6.1–7.0 cm length, which corresponds to the end of the period of rapid elongation. Apical portions of fruit bodies with caps grew better on glucose than whole fruit bodies. Growth of decapitated isolated stipes was not promoted by nutrients.


2020 ◽  
pp. 1-9
Author(s):  
Keum-Ah Lee ◽  
Youngnam Kim ◽  
Hossein Alizadeh ◽  
David W.M. Leung

Abstract Seed priming with water (hydropriming or HP) has been shown to be beneficial for seed germination and plant growth. However, there is little information on the effects of seed priming with amino acids and casein hydrolysate (CH) compared with HP, particularly in relation to early post-germinative seedling growth under salinity stress. In this study, Italian ryegrass seeds (Lolium multiflorum L.) were primed with 1 mM of each of the 20 protein amino acids and CH (200 mg l−1) before they were germinated in 0, 60 and 90 mM NaCl in Petri dishes for 4 d in darkness. Germination percentage (GP), radicle length (RL) and peroxidase (POD) activity in the root of 4-d-old Italian ryegrass seedlings were investigated. Generally, when the seeds were germinated in 0, 60 and 90 mM NaCl, there was no significant difference in GP of seeds among various priming treatments, except that a higher GP was observed in seeds of HP treatment compared with the non-primed seeds when incubated in 60 mM NaCl. When incubated in 60 and 90 mM NaCl, seedlings from seeds primed with L-methionine or CH exhibited greater RL (greater protection against salinity stress) and higher root POD activity than those from non-primed and hydro-primed seeds. Under salinity stress, there were higher levels of malondialdehyde (MDA) in the root of 4-d-old Italian ryegrass seedlings, a marker of oxidative stress, but seed priming with CH was effective in reducing the salinity-triggered increase in MDA content. These results suggest that priming with L-methionine or CH would be better than HP for the protection of seedling root growth under salinity stress and might be associated with enhanced antioxidative defence against salinity-induced oxidative stress.


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