32 research outputs found
1,8-Cineole Inhibits Both Proliferation and Elongation of BY-2 Cultured Tobacco Cells
Volatile monoterpenes such as 1,8-cineole inhibit the growth of Brassica campestris seedlings in a dose-dependent manner, and the growth-inhibitory effects are more severe for roots than hypocotyls. The preferential inhibition of root growth may be explained if the compounds inhibit cell proliferation more severely than cell elongation because root growth requires both elongation and proliferation of the constituent cells, whereas hypocotyl growth depends exclusively on elongation of existing cells. In order to examine this possibility, BY-2 suspension-cultured tobacco (Nicotiana tabacum) cells were treated with 1,8-cineole, and the inhibitory effects on cell proliferation and on cell elongation were assessed quantitatively. Treatment with 1,8-cineole lowered both the mitotic index and elongation of the cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC50) for cell elongation was lower than that for cell proliferation. Moreover, 1,8-cineole also inhibited starch synthesis, with IC50 lower than that for cell proliferation. Thus, the inhibitory effects of 1,8-cineole were not specific to cell proliferation; rather, 1,8-cineole seemed inhibitory to a variety of physiological activities when it was in direct contact with target cells. Based on these results, possible mechanisms for the mode of action of 1,8-cineole and for its preferential inhibition on root growth are discussed
Root-emitted volatile organic compounds: can they mediate belowground plant-plant interactions?
peer reviewedBackground
Aboveground, plants release volatile organic compounds (VOCs) that act as chemical
signals between neighbouring plants. It is now well documented that VOCs emitted by
the roots in the plant rhizosphere also play important ecological roles in the soil
ecosystem, notably in plant defence because they are involved in interactions between
plants, phytophagous pests and organisms of the third trophic level. The roles played
by root-emitted VOCs in between- and within-plant signalling, however, are still poorly
documented in the scientific literature.
Scope
Given that (1) plants release volatile cues mediating plant-plant interactions
aboveground, (2) roots can detect the chemical signals originating from their
neighbours, and (3) roots release VOCs involved in biotic interactions belowground,
the aim of this paper is to discuss the roles of VOCs in between- and within-plant
signalling belowground. We also highlight the technical challenges associated with the
analysis of root-emitted VOCs and the design of experiments targeting volatile-mediated
root-root interactions.
Conclusions
We conclude that root-root interactions mediated by volatile cues deserve more
research attention and that both the analytical tools and methods developed to study
the ecological roles played by VOCs in interplant signalling aboveground can be
adapted to focus on the roles played by root-emitted VOCs in between- and within-plant
signalling