Molecular Interventions to Ameliorate Environmental Stresses in Orchids

Orchids constitute one of the largest, diverse, cosmopolitan and highly evolved plant families, the Orchidaceae. Due to their poorly developed reproductive barriers, they are in a constant state of evolutionary flux and active speciation. Epiphytic habit in orchids, expose these plants to light and water stress which in turn encourage modifications and adaptations. The flowers have a complex structure with one of the petal being variously modified into a labellum, which forms the basis of their immense importance as ornamentals. As a result, they are in huge demand in floriculture industry. Additionally, orchids have been significantly reported in ancient therapeutic scriptures. There have been a large number of reports of their curative and restorative role potential. They are considered to be highly habitat specific and show poor propagation in nature owing to their microscopic seeds with undifferentiated embryos and no endosperm, and dependence on a symbiotic association with mycorrhizal fungi for continued germination. They are also considered to be good indicators of environmental degradation. Owing to their immense demand in floriculture industry as well as therapeutics, these plants have been under constant stress from various environmental sources as well as anthropogenic pressures. With the advent of molecular technology, there have been constant efforts to ameliorate the deleterious effects of environment stresses in orchids. The present review deals with the various molecular interventions involved in dealing with these environmental stresses.