Mass spectrometric evidence for the occurrence of plant growth promoting cytokinins in vermicompost tea

• Published in: Biology and fertility of soils 2014-11, Vol.50 (2), p.401-403
• Main Authors: Zhang, H, Tan, S. N, Wong, W. S, Ng, C. Y. L, Teo, C. H, Ge, L, Chen, X, Yong, J. W. H
• Format: Article
• Language: English
• Subjects: abscisic acid; Agriculture; Agronomy. Soil science and plant productions; Aquatic plants; auxins; Biochemistry and biology; Biological and medical sciences; Biomedical and Life Sciences; Chemical, physicochemical, biochemical and biological properties; cytokinins; earthworms; Eichhornia crassipes; Fertilizers; Floating plants; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; growth and development; Life Sciences; Liquid chromatography; Mass spectrometry; Microbial activity; microbial communities; Organic fertilizers; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant growth; Poultry manure; Short Communication; Soil fertility; Soil science; Soil Science & Conservation; Soil-plant relationships. Soil fertility. Fertilization. Amendments; solid phase extraction; Studies; tea; Vermicomposting; Worms; Zoology (interactions between soil fauna and agricultural or forest soils)
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/s00374-013-0846-y

Through their decomposing activities, earthworms produce rich organic fertilizers called vermicomposts containing mineral nutrients and anecdotal evidence of biologically active phytohormones. Aqueous extracts of vermicomposts, namely vermicompost tea (VT), have positive effects on plant growth. It has been postulated that trace amounts of phytohormones in vermicomposts or its VT are beneficial for plant growth and development. We therefore screened for the different classes of phytohormones (auxins, cytokinins, abscisic acid, and gibberellin) in VT using liquid chromatography–tandem mass spectrometry (LC–MS/MS) after solid-phase extraction. VT was produced by earthworms being fed with a mixture of water hyacinth (Eichhornia crassipes) and chicken manure at a ratio of 4:1 (w/w). This investigation is the first mass spectrometric evidence for the presence of cytokinins in VT: namely trans-Zeatin (tZ), N⁶-Isopentenyladenine (iP) and N⁶-Isopentenyladenosine (iPR), which were present at 0.06, 3.33, and 0.02 nmol L–¹, respectively. The successful detection and quantitation of cytokinins in VT provided direct evidence to explain the growth efficacy of applying VT in order to enhance plant growth and development. We postulated that they were microbially synthesized due to the abundance of microbial communities in the vermicompost.