Isolation, Identification, and Autotoxicity Effect of Allelochemicals from Rhizosphere Soils of Flue-Cured Tobacco

Abstract

Autotoxicity, defined as a deleterious allelopathic effect among individuals of the same plant species, is considered as one of the factors that contributes to replant failure. Tobacco, as an important cultured and economic crop over the world, has been often hampered by replant failure. In view of the seriousness of this problem, the allelochemicals of flue-cured tobacco and their allelopathic effects were investigated. The extracts of rhizosphere soil exhibited phytotoxic activities against Lactuca sativa and autotoxic activities against tobacco itself. Bioassay-guided fractionation of the extract led to the isolation of six compounds, the structures of which were elucidated by spectroscopic analysis. Among them, β-cembrenediol (1), di-n-hexyl phthalate (2), and bis(2-propylheptyl) phthalate (3) showed observably phytotoxic activities against L. sativa seedlings and autotoxic activities on tobacco. The allelochemicals were then verified in the root zone soils of flue-cured tobacco by high-performance liquid chromatography (HPLC). These results provide new insights into the allelopathic mechanisms involved in the replant failure of flue-cured tobacco.

Recent advances in allelopathy for weed control: from knowledge to applications

“…High stability, combined with low water solubility, promotes soil retention of these compounds. In the case of tobacco, ergosta‐5‐en‐3‐ol causes a slight reduction in the root and stem lengths of its own crop . Furthermore, plants are evolving genotypes resistant to this phytotoxin due to continuous exposure.…”

ALLELOPATHIC EFFECT OF Β-Cembrenediol AND ITS MODE OF ACTION: INDUCED OXIDATIVE STRESS IN LETTUCE SEEDLINGS

“…The rates of dead cells in the the two compounds were 60% of the total cuticular secreta of tobacco leaf and flower (Johnson et al,1985). Recent studies indicated that β-cembrenediol played an allelochemical-affecting growth of L. sativa and tobacco itself (Ren et al, 2015). In this study, lettuce seedlings were used as a receptor to illustrate the action mechanism for the phytotoxicity of β-cembrenediol.…”

“…grade and used without purification. β-Cembrenediol was isolated according to previous procedures (Ren et al, 2015). It was characterized ( Fig.…”

“…A crude extract of tobacco rhizospheric soil significantly inhibited the seed germination as well as root and shoot growth of lettuce and tobacco (Chen et al, 2012;Yu et al, 2014). In earlier studies, it was determined the specific allelochemicals of the extract from rhizosphere soil of tobacco and studied their biotoxicity (Ren et al, 2015). By showing inhibitory effects against lettuce and tobacco seedlings and being detected in the root zone soils of tobacco, β-cembrenediol was recognized as an important and main allelochemical (Ren et al, 2015).…”

“…In earlier studies, it was determined the specific allelochemicals of the extract from rhizosphere soil of tobacco and studied their biotoxicity (Ren et al, 2015). By showing inhibitory effects against lettuce and tobacco seedlings and being detected in the root zone soils of tobacco, β-cembrenediol was recognized as an important and main allelochemical (Ren et al, 2015). However, the detailed mechanism of action for the phytotoxicity of β-cembrenediol remained unknown.…”