Development of tolerance to the phytoalexin 6-methoxymellein in microorganisms.

Kurosaki, Fumiya; Sakurai, Izumi; Nishi, Arasuke

doi:10.2323/jgam.30.43

Cited by 6 publications

(2 citation statements)

References 4 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In all these cases, resistance to phytoalexins of the isoflavonoid type is inducible by isoflavonoids. In addition, an inducible resistance of fungi to a phytoalexin of carrots has been observed (24). Our data constitute the first report of an inducible phytoalexin resistance in a bacterial species.…”

Section: Discussionsupporting

confidence: 50%

Isoflavonoid-inducible resistance to the phytoalexin glyceollin in soybean rhizobia

1991

View full text Add to dashboard Cite

The antibacterial effect of the soybean phytoalexin glyceollin was assayed using a liquid microculture technique. Log-phase cells of Bradyrhizobium japonicum and Sinorhizobium fredii were sensitive to glyceollin.As revealed by growth rates and survival tests, these species were able to tolerate glyceollin after adaptation. (8,9,21,38,42).In a number of plant-pathogen interactions, the induction of phytoalexins, plant-derived antimicrobial low-molecularweight molecules, is believed to play an essential part in host resistance (10, 43). In several legumes, phytoalexins belong to the isoflavonoid type (e.g., pisatin in Pisum sp.; glyceollin in Glycine sp.; medicarpin in Medicago sp.). This is of special interest because flavonoids have been shown to be regulators of rhizobial nod gene activity (see reference 25 for a review). Considering the microsymbionts of soybean, the most active inducing compounds are isoflavonoids (1,14,22). Despite this intriguing bifunctionality of isoflavonoids, i.e., regulatory substances and phytoalexins, only a few data are available concerning the significance of phytoalexins in the interaction between rhizobia and their legume host. Pankhurst and co-workers studied the inhibition of rhizobia by isoflavonoids (28) as well as by flavolans (31). They found an ineffective Rhizobium strain to be more sensitive to the root flavolan of the host plant Lotus corniculatus than its effective counterpart (30). In addition, the ineffective strain induced the synthesis of higher flavolan concentrations in the nodules of this plant (29). Taken together, these results indicate the importance of flavonoids as toxic compounds for rhizobia, which may have consequences for the symbiotic interaction.Glyceollin, a phytoalexin of soybean ( Fig. 1), is strongly induced in response to a number of biological, chemical, and physical stresses, e.g., infection with pathogenic fungi, the presence of heavy metals, or UV radiation (10,19,45

show abstract

Section: Discussionsupporting

confidence: 50%

Isoflavonoid-inducible resistance to the phytoalexin glyceollin in soybean rhizobia

1991

View full text Add to dashboard Cite

show abstract

“…The yield of (i-)-phaseollin from the acetal (185) was 30%. In order to prevent competing side-reactions of the double-bond of the chromene, this was protected by regioselective radical addition163 of thiophenol [(183) -+ (188), as shown in Scheme 20b] and later regenerated by pyrolysis of the sulphoxides of (190) and (192). Extension of the synthesis to (+)-phaseollidin is feasible, since phaseollidin has been obtained by reduction of natural phaseollin.…”

Section: The Total Synthesis Of (K )-Phaseohmentioning

confidence: 99%