Article

Genistein and Daidzein Concentrations and Contents in Seedling Roots of Three Soybean Cultivars Grown under Three Root Zone Temperatures

Department of Plant Science, McGill University, Montréal, Quebec, Canada
Journal of Agronomy and Crop Science (Impact Factor: 2.44). 04/2008; 180(2):77 - 82. DOI: 10.1111/j.1439-037X.1998.tb00374.x

ABSTRACT

Daidzein and genistein are plant-to-bacterium signal compounds involved in soybean nodule formation. They can induce nod gens expression in Bradyrhizobium japonicum. The objective of this study was to determine whether the production of signal molecules was affected by low root zone temperatures (RZTs) in a manner that varied among soybean cultivars. Daidzein and genistein concentrations of soybean seedling roots were measured at three RZTs by high performance liquid chromatography (HPLC). The results indicated that daidzein content and concentration per plant were higher at 15 and 17.5°C than those at 25°C. AC Bravor had higher daidzein contents and concentrations than did Maple Glen and KG20. At 17.5°C. KG20 had higher genistein content and concentration levels than Maple Glen, and no difference existed for the two cultivars at 15 and 25 C. Daidzein contents and concentrations of Maple Glen and AC Bravor increased with harvest time. However, for cultivar KG20, the content and concentration decreased at 19 days after inoculation. Genistein contents and concentrations of the three cultivars increased under each RZT up to the last harvest. There was an interaction between soybean cultivar and RZT for root genistein and daidzein contents and concentrations. The content and concentration of daidzein in soybean seedling roots were much higher (more than five times) than those of genistein.

1 Follower
 · 
16 Reads
  • Source
    • "High temperature (39 8C) increases the release of the isoflavonoid signals from soybean seeds during the first 24 h, but the compounds released have decreased nod gene-inducing activities (Hungria and Stacey, 1997). The addition of genistein to the inoculant or the rhizosphere could at least partially alleviate the deleterious effects of these environmental factors (Zhang and Smith, 1995, 1996b, 1997; Smith and Zhang, 1996; Hungria and Stacey, 1997; Pan et al., 1998). Besides inhibiting the synthesis and excretion of isoflavonoids by soybean roots, low RZTs also suppress bacterial nod gene expression, and this also could be partially overcome by genistein application (Zhang et al., 1996a). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Serratia proteamaculans 1-102 (1-102) promotes soybean-bradyrhizobia nodulation and growth, but the mechanism is unknown. After adding isoflavonoid inducers to 1-102 culture, an active peak with a retention time of about 105 min in the HPLC fractionation was isolated using a bioassay based on the stimulation of soybean seed germination. The plant growth-promoting activity of this material was compared with 1-102 culture (cells) and supernatant under greenhouse conditions. The activator was applied to roots in 83, 830 and 8300 HPLC microvolts (microV) per seedling when plants were inoculated with bradyrhizobia or sprayed onto the leaves in same concentrations at 20 d after inoculation. The root-applied activator, especially at 1 ml of 830 microV per seedling, enhanced soybean nodulation and growth at the same level as 1-102 culture under both optimal and sub-optimal root zone temperatures. Thus, this activator stimulating soybean seed germination is also responsible for the plant growth-promoting activity of 1-102 culture. However, when sprayed onto the leaves, the activator did not increase growth and in higher concentrations decreased average single leaf area. The results suggest that this inducible activator might be a lipo-chitooligosaccharide (LCO) analogue. LCOs act as rhizobia-to-legume signals stimulating root nodule formation. The activator could provide additional 'signal', increasing in the signal quality (the signal-to-noise ratio, SNR) of the plant-rhizobia signal exchange process.
    Full-text · Article · Jul 2002 · Journal of Experimental Botany
  • Source
    • "High temperature (39 8C) increases the release of the isoflavonoid signals from soybean seeds during the first 24 h, but the compounds released have decreased nod gene-inducing activities (Hungria and Stacey, 1997). The addition of genistein to the inoculant or the rhizosphere could at least partially alleviate the deleterious effects of these environmental factors (Zhang and Smith, 1995, 1996b, 1997; Smith and Zhang, 1996; Hungria and Stacey, 1997; Pan et al., 1998). Besides inhibiting the synthesis and excretion of isoflavonoids by soybean roots, low RZTs also suppress bacterial nod gene expression, and this also could be partially overcome by genistein application (Zhang et al., 1996a). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Serratia proteamaculans 1‐102 (1‐102) promotes soybean–bradyrhizobia nodulation and growth, but the mechanism is unknown. After adding isoflavonoid inducers to 1‐102 culture, an active peak with a retention time of about 105 min in the HPLC fractionation was isolated using a bioassay based on the stimulation of soybean seed germination. The plant growth‐promoting activity of this material was compared with 1‐102 culture (cells) and supernatant under greenhouse conditions. The activator was applied to roots in 83, 830 and 8300 HPLC microvolts (μV) per seedling when plants were inoculated with bradyrhizobia or sprayed onto the leaves in same concentrations at 20 d after inoculation. The root‐applied activator, especially at 1 ml of 830 μV per seedling, enhanced soybean nodulation and growth at the same level as 1‐102 culture under both optimal and sub‐optimal root zone temperatures. Thus, this activator stimulating soybean seed germination is also responsible for the plant growth‐promoting activity of 1‐102 culture. However, when sprayed onto the leaves, the activator did not increase growth and in higher concentrations decreased average single leaf area. The results suggest that this inducible activator might be a lipo‐chitooligosaccharide (LCO) analogue. LCOs act as rhizobia‐to‐legume signals stimulating root nodule formation. The activator could provide additional ‘signal’, increasing in the signal quality (the signal‐to‐noise ratio, SNR) of the plant–rhizobia signal exchange process.
    Preview · Article · Jun 2002 · Journal of Experimental Botany
  • [Show abstract] [Hide abstract]
    ABSTRACT: Isoflavonoids, as plant-to-bacteria signal molecules, play an important role in the establishment of the soybean (Glycine max (L.) Merr.) Bradyrhizobium japonicum nitrogen (N) fixing symbiosis. They are essential to the development of effective root nodules and responsible for inducing the nod genes of B. japonicum. Because N affects a broad range of infection events, especially the symbiotic events occurring within 18 h of inoculation, it is reasonable to hypothesize that mineral N disrupts the interorganismal signal exchange between soybean host plants and B. japonicum. High performance liquid chromatographic (HPLC) analysis of root extracts of soybean, inoculated with B. japonicum or not, grown with various levels of mineral N in the rooting medium were performed to test this hypothesis. The results of these studies indicated that: (1) at early plant growth stages (before the onset of N fixation), a strong negative relationship between N application and soybean root isoflavonoid (genistein and daidzein) concentrations existed; (2) although isoflavonoid (genistein and daidzein) concentrations in both inoculated and non-inoculated soybean root systems were generally decreased by N application, at very low N levels (10 mg N l(-1)) genistein in the non-inoculated plant roots was not decreased relative to the 0 N plants; (3) averaged over all mineral N treatment levels and sampling times, inoculation of soybean with B, japonicum increased root daidzein concentrations (P > 0.05), but did not affect genistein. Overall, N application reduced the isoflavonoid concentration of soybean root systems, which probably plays a part in the regulation of soybean nodule formation by available N.
    No preview · Article · Apr 2000 · Journal of Agronomy and Crop Science
Show more