Brassinosteroids (BRs) are ubiquitous plant steroid hormones, playing diverse roles in plant
growth, development and stress responses. Defects in BRs biosynthesis or signaling result in physiologic
and phenotypic abnormalities. To date, numerous studies have highlighted BRs-induced stress
tolerance to various environmental extremes such as high temperature, chilling, drought, salinity and
heavy metals in a range of plant species. However, the in-depth mechanisms of BRs-induced stress
tolerance still remain largely unknown. It is now clear that BRs-induced stress responses are strictly concentration dependent
and the optimal concentration for improving the plant adaptability may vary depending on the plant species, developmental
stages and environmental conditions as well. Conflicting evidences concerning regulation of stress adaptation
by BRs demand further elucidation of mechanism of BRs action in response to environmental stresses in plants. Recent
advances in phytohormone research suggest that the effect of BRs on stress tolerance relies largely on its interplay with
other hormones. In this review, we critically analyze the multifaceted roles of BRs in various abiotic stresses and its potential
crosstalk with other hormones in stress adaptation. The discrepancy in the dose and mode of application of BRs
analogues for stress management is also discussed.
Keywords: Brassinosteroids, dose-effect, environmental extremes, hormone crosstalk, stress tolerance.
Rights & PermissionsPrintExport