Physiological and Molecular Role of Strigolactones as Plant Growth Regulators: A Review.

Abstract

Strigolactones (SLs) are plant hormones that regulate a number of developmental and environmental processes among different species, including both mono- and dicotyledonous plants and are intensively studied during the last few years. Even though SLs were originally determined as negative regulators of the branching of the aboveground part of plants gradually it was revealed that these root-derived chemical signals are also involved in regulating symbiotic and parasitic relationships with mycorrhizal fungi microbes and root parasitic plants, respectively. There has been substantial advancement in the development of SL research since the invention of SLs hormonal function. Significant progress has been made in revealing the role of strigolactones in the adaptation to abiotic stresses, plant growth, the elongation of the mesocotyl and stem, secondary growth and shoot gravitropism in the last few years. The discovery of SLs hormonal function was extremely valuable because it resulted in the recognition of a new family of plant hormones including the promisedSL biosynthetic and way to respond mutants. Subsequent reports on the numerous roles of strigolactones in plant growth and development, also in stress responses, mainly in response to nutrient stress, including phosphorus (P) and nitrogen (N) deficiency or crosstalk with other hormones, have indicated that there might still be some unveil functions of strigolactones in plants.With the use of various mutants from a variety of plant species, fundamental issues concerning SL biosynthesis and perception were investigated. Molecular analyses of these biologically identified factors have been carried out. Only the broad strokes of SL synthesis pathway and recognition have been revealed thus far. In addition, reverse genetic analyses have revealed new genes involved in SL transport. Current advancement in SLs study with an emphasis on biogenesis and insight is summarized in his review.