Cytokinin production by microorganisms

Greene, Elizabeth M.

doi:10.1007/bf02860866

Cited by 99 publications

(51 citation statements)

References 178 publications

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“…Similarly, high cytokinin activity in the culture medium and the presence of zeatin ribonucleotides in the tRNA have been correlated with pathogenicity and with the presence of plasmids in Agrobacterium tumefaciens (24,25). High contents of zeatin or its derivatives are also present in other organisms that cause overgrowths in plants, such as mycorrhizal fungi (26), gall-forming insects (27)(28)(29), etc. (29), even though hydroxylated isopentenyladenines normally are found neither in fungi nor in animals (29,30).…”

Section: Discussionmentioning

confidence: 99%

“…High contents of zeatin or its derivatives are also present in other organisms that cause overgrowths in plants, such as mycorrhizal fungi (26), gall-forming insects (27)(28)(29), etc. (29), even though hydroxylated isopentenyladenines normally are found neither in fungi nor in animals (29,30). These results raise the question of whether DNA that codes for high cytokinin production and zeatin biosynthesis in prokaryotic plant pathogens, and in the case of A. tumefaciens may be transmitted to serve this function in host tissue, is of prokaryotic origin or has been acquired by the pathogens from plants during evolution.…”

Section: Discussionmentioning

confidence: 99%

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Relationships between cytokinin production, presence of plasmids, and fasciation caused by strains of Corynebacterium fascians

Murai

Skoog

Doyle

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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Cytokinin activity in the culture medium of four pathogenic strains of Corynebacterium fascians varied from 168 to 0.4 jsg of kinetin (6-furfurylaminopurine) equivalents per liter, as compared to 0.2 in an avirulent control. NA-Isopentenyladenine was the predominant cytokinin in the medium of all five strains, and its increased production was correlated with the degree of pathogenicity; however, the virulent strains also produced 8-13 times more cis-zeatin [6(4-hydroxy-3-methyl-cis-2-butenylamino)purineJ than the avirulent strain. as 644-hydroxy-3-methyl-cis-2-butenylamino)9-0-D-ribofuranosylpurine, 6q3methyl-2-butenylamino.9-j-D-ribofuranosylpurine, and their 2-methylthio derivatives. The fifth cytokinin was tentatively identified as 6(4-hydroxy-3-methyl-trans-2-butenylamino)9-#-D-ribofuranosylpurine. Ribosyl-cis-zeatin was 3fold higher and N6-isopentenyladenosine was correspondingly lower in the plasmid-containing strains than in the plasmidless control. Because the entire syndrome of fasciation caused by infection can be induced with synthetic cytokinins, the disease would appear to be caused by plasmid-induced high rates of cytokinin production by the bacteria. Corynebacterium fascians causes fasciation disease or witches' broom in dicotyledonous plants. The disease is characterized by release of apical dominance and outgrowth of lateral buds, which gives rise to the characteristic witches' broom syndrome (1). The symptoms of the disease can be duplicated by treatment of seeds or seedlings with cytokinins, indicating that it may be caused by cytokinins produced by the microbe (2). From C. fascians culture medium four cytokinins, 6-(3-methyl-2-butenylamino)purine. (i6Ade), 6-(4-hydroxy-3-methyl-cis-2-butenylamino)purine (c-io6Ade), 6-(4-hydroxy -3-methyl-cis -2-butenylamino) -2-methylthiopurine (ms2-c-io6Ade), and 6-methylaminopurine (m6Ade),.have been characterized, and three additional cytokinins, 6-(4-hydroxy-3-methyl-trans-2-butenylamino)purine (t-io6Ade), 6-(4-hydroxy-3-methyl-2-butenylamino)-9-/3-D-ribofuranosylpurine (io6A), and 6-(3-methyl-2-butenylamino)-9-f3-D-ribofuranosylpurine (i6A), have been tentatively identified (3-6). The tRNA of the bacterium has been reported to contain several cytokinins (7-9), but only c-io6A has been rigorously identified (10). Biosynthesis of the i6A moiety in tRNA involves the transfer of isopentenyl from A2-isopentenyl pyrophosphate to specific adenosine residues in preformed tRNA (11,12), and it has been proposed that i6Ade and other free cytokinins in the culture medium derive from tRNA degradation. The existence of alternative pathways is probable, as suggested by the in vitro synthesis of free i6Ade from AMP and A2-isopentenyl pyrophosphate recently achieved with an enzyme preparation from Dictyostelium (13). 619This report deals with the kinds and quantities of cytokinins released into culture media and present in tRNA of five strains of C. fascians, ranging from highly virulent to avirulent, and examines relationships of the presence of plasmids to cyto...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Relationships between cytokinin production, presence of plasmids, and fasciation caused by strains of Corynebacterium fascians

Murai

Skoog

Doyle

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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“…Such a complementation was observed, however, when pMGV100 was introduced in fas6 ( Table 2), indicating that at least one of the three ORFs, or a combination thereof, located upstream of ipt is essential for pathogenesis. fascians (42) has for a long time been considered as the prototype of a plant-bacterium interaction requiring only cytokinin production to cause neoplastic growth (15). Several cytokinins have been detected in small amounts in the supernatants of some virulent R. fascians cultures (25,30,31) but not in other virulent cultures (1,8), indicating that the phytopathogenicity of R. fascians involves more than mere cytokinin secretion.…”

Section: Figmentioning

confidence: 99%

The fas operon of Rhodococcus fascians encodes new genes required for efficient fasciation of host plants

et al. 1994

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Three virulence loci (fas, ftt, and hyp) of Rhodococcus fascians D188 have been identified on a 200-kb conjugative linear plasmid (pFiD188). The fas locus was delimited to a 6.5-kb DNA fragment by insertion mutagenesis, single homologous disruptive recombination, and in trans complementation of different avirulent insertion mutants. The locus is arranged as a large operon containing six open reading frames whose expression is specifically induced during the interaction with host plants. One predicted protein is homologous to P-450 cytochromes from actinomycetes. The putative ferredoxin component is of a novel type containing additional domains homologous to transketolases from chemoautotrophic, photosynthetic, and methylotrophic microorganisms. Genetic analysis revealed thatfas encodes, in addition to the previously identified ipt, at least two new genes that are involved in fasciation development, one of which is only required on older tobacco plants.The interaction between Rhodococcus fascians and host plants leads to the loss of apical dominance and the development of multiple malformed shoots at the site of infection (fasciation). This proliferation is governed by multiple bacterial loci located both on a linear Fi plasmid and on the chromosome (reference 8 and unpublished results). From the three identified loci on pFiD188, only inactivation of one (fas) leads to a complete loss of phytopathogenicity. In this locus, an open reading frame (ORF) coding for an isopentenyltransferase (ipt) has been identified by sequence homology to other cytokinin biosynthesis genes and by biochemical approaches (8). Expression of ipt in R. fascians is regulated by an inducing factor which can only be detected in significant amounts in extracts from tumor tissues (induced by R. fascians) (8).In this paper, we present genetic data that allowed the definition of the fas locus on a 6.5-kb DNA fragment whose complete nucleotide sequence was determined. Six ORFs directed in the same orientation as the previously defined ipt were identified. ORFi and the amino-terminal part of ORF2 have extensive homologies, to P-450 cytochromes and ferredoxins from actinomycetes, whereas the carboxy-terminal portion of ORF2 has conserved regions homologous to the aminoterminal part of transketolases from chemoautotrophic, photosynthetic, or methylotrophic microorganisms.The isolation of new fas mutants and complementation analysis revealed that fas encodes new genes involved in fasciation of the host plant.MATERIALS AND METHODS Bacterial strains and plasmids. Growth conditions and antibiotic concentrations for R. fascians strains have been described previously (11). The Escherichia coli strains used for

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“…This phenomenon also applies to higher plants. Generally, microbial cytokinins produce pathological symptoms in higher plants (Greene 1980). An example of this is Corynebacterium fascians, who is responsible for fasciation disease in plants, due to the presence of cytokines ribosyl type Z (Einset and Skoog 1977).…”

Section: Introductionmentioning

confidence: 99%

GROWTH PROMOTER EFFECT ON THE B. braunii KUTZING 1849 CULTURE BY SEVERAL DIFFERENT BACTERIAL STRAINS

et al. 2017

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There are several strategies to improve the growth of microalgae in industrial processes. In recent years, one of them has gained strength to achieve this goal: the co-culture with bacteria. Using growth-promoting substances, producer bacteria enhance microalgae biology activity, similar to how they have been used to promote the successful production of crops. The aim of this study was to evaluate the promoter capacity of strains Bacillus subtilis, Corynebacterium aquatile and Flavobacterium aquatile, evaluate their ability to improve the growth rate of microalgae Botryococcus braunii and to optimize the process derived from its cultivation. This study showed that the tested bacteria were able to increase up to 1.7 times the B. braunii growth rate and this promoting ability remained present in cell lysate preparations from the same bacterial strains. Key words: Botryococcus braunii, Flavobacterium aquatile, Corynobacterium aquatile, Bacillus subtilis, microbial elicitation, co-cultivation ResumenEl empleo de bacterias productoras de sustancias promotoras de crecimiento, para mejorar la eficiencia en el crecimiento de las microalgas y así potenciar su actividad en procesos industriales es una práctica que ha tomado fuerza durante los últimos años, de manera análoga a como han sido utilizadas las bacterias para favorecer la producción exitosa de cultivos vegetales. El objetivo de este trabajo fue evaluar la capacidad de las cepas Flavobacterium aquatile, Corynobacterium aquatile y Bacillus subtilis de actuar como promotoras en el crecimiento de la microalga Botryococcus braunii con el fin de mejorar su velocidad de crecimiento y optimizar los procesos derivados de su cultivo. Este estudio muestra que las bacterias evaluadas tienen la capacidad de aumentar hasta 1,7 veces el crecimiento de B. braunii y esta capacidad promotora continúa presente en preparaciones de lisados celulares procedentes de estas mismas cepas bacterianas.

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Cytokinin production by microorganisms

Cited by 99 publications

References 178 publications

Relationships between cytokinin production, presence of plasmids, and fasciation caused by strains of Corynebacterium fascians

Relationships between cytokinin production, presence of plasmids, and fasciation caused by strains of Corynebacterium fascians

The fas operon of Rhodococcus fascians encodes new genes required for efficient fasciation of host plants

GROWTH PROMOTER EFFECT ON THE B. braunii KUTZING 1849 CULTURE BY SEVERAL DIFFERENT BACTERIAL STRAINS

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