Concentration-dependent influence of quercetin on nodulation process and the main characteristics of soybean inoculated with Bradyrhizobium japonicum

Abstract

Soybean plants cv. Corsoy were grown in greenhouse conditions on sterilized quartz sand. They were inoculated with Bradyrhizobium japonicum, strain 542. The plants were treated with different concentrations of quercetin (ranging from 10 nM to 1/~M at regular intervals during the experiment. The experiment was terminated at flower development. The following parameters, important for symbiosis efficiency were determined: shoot, root and nodule weights, nodule number, total leghemoglobin in the nodules,total nitrogen and soluble protein concentrations in shoots and roots, as well as chlorophyll concentration in the leaves.The results obtained partly confirmed the earlier findings that quercetin inhibits nodulation since increasing quercetin concentration decreased the number of nodules. However, at very low concentrations, quercetin stimulated the number of nodules. Quercetin also exerted a stimulating influence on other characteristics of the plant and nodules which did not correlate with nodule number and quantity of N fixed. These are: nodule weight, leghemoglobin concentration, total soluble protein content in shoots and roots as well as shoot and root weight.

Level of Catechin, Myricetin, Quercetin and Isoquercitrin in Buckwheat (Fagopyrum esculentum Moench), Changes of Their Levels during Vegetation and Their Effect on The Growth of Selected Weeds

“…T. repens was among the least sensitive species. According to Mihailovic et al (32), quercetin inhibits the nodulation of soy, given that an increasing quercetin concentration decreased the number of nodules; however, very low quercetin concentrations stimulated the number of nodules. Inderjit and Dakshini (29) suggested quercetin as the allelopathic compound of Pluchaea lanceolata.…”