The dynamic linkage between phytotoxicity and metabolites in Wedelia trilobata soils

Abstract

The phytotoxicity of soils under Wedelia trilobata has been described, but the dynamic between phytotoxic and metabolites in W. trilobata soil and the restriction posed by soil properties have been poorly addressed. In this study, the phytotoxic variation of W. trilobata soil in response to the changes in soil properties and soil metabolomics was determined at monthly intervals for 11 months using bioassays and metabolomic approaches. Strong variability in soil properties and obvious temporal variations in the soil phytotoxicity were observed over the 11‐month period. Among the soil properties that were analyzed, soil organic matter, electrical conductivity, total nitrogen, and soil nutrients presented the most contribution in differentiating soils according to time of sampling and strength of phytotoxicity. Nonsterilized soil exerted stronger percentage inhibition of seed germination (IG) of lettuce, whereas the percentage inhibition of shoot height (SH) and root length (RL) of lettuce was higher in sterilized soil. Decline in the overall phytotoxicity was clearly observed in nonsterilized soil, suggesting the role of soil microbes in mediating the soil phytotoxic effect of W. trilobata, albeit the negative correlation. Putative metabolites contributing to the discrimination of soils according to time of sampling and strong correlation with percentage inhibition (%) of IG, SH, and RL were identified and discussed. Overall, the results showed that the phytotoxicity of soils under W. trilobata varied throughout the 11 months of study and can be restricted by the changes in soil properties.

Dose‐Dependent Effect of Wedelia trilobata Essential Oil (EO) on Lettuce (Lactuca sativa L.) with Multivariate Analysis

“…al. [18] In this study, Wedelia trilobata (L.) Hitchc. was grown and maintained in a growth chamber under the following conditions: 12 h light: 12 h dark; temperature: day 28 °C, night 20 °C; humidity: day 65 %, night 75 %, and 30,000 lux light.…”

“…Seed bioassay experiments were conducted according to Azizan et al [18] A total of 20 lettuce (Lactuca sativa L.) seeds were germinated on two layers of filter paper (Whatman No. 1), in a sterilized petri dish (9 cm × 15 mm).…”