The physiological importance of glucosinolates on plant response to abiotic stress in Brassica

Abstract

Glucosinolates, a class of secondary metabolites, mainly found in Brassicaceae, are affected by the changing environment. This review is focusing on the physiological significance of glucosinolates and their hydrolysis products in the plant response to different abiotic stresses. Special attention is paid to the crosstalk between some of the physiological processes involved in stress response and glucosinolate metabolism, with the resulting connection between both pathways in which signaling mechanisms glucosinolate may act as signals themselves. The function of glucosinolates, further than in defense switching, is discussed in terms of alleviating pathogen attack under abiotic stress. The fact that the exogenous addition of glucosinolate hydrolysis products may alleviate certain stress conditions through its effect on specific proteins is described in light of the recent reports, but the molecular mechanisms involved in this response merit further research. Finally, the transient allocation and re-distribution of glucosinolates as a response to environmental changes is summarized.

Figure 1

Effect of abiotic stress on glucosinolates (GLS)/allyl-isothiocyanates (ITC) content. (1) The chain-elongation steps of glucosinolates biosynthesis are affected by abiotic stress; (2) Stress perception may lead to increased synthesis of any secondary messenger in the cytosol, facilitating the release of the glucosinolates to the cytoplasm from the vacuole (3). The activity of plant myrosinases will product (allyl-) isothiocyanates (4) that might regulate the transduction or accumulation of other transporters or channels in the plasma membrane (5).