INTEGRATED MULTI-OMICS AND MICROBIOME APPROACHES FOR BIOPROSPECTING STRESS-INDUCED SECONDARY METABOLITES IN HALOPHYTES

Abstract

Halophytes, which are chemically rich yet largely unexplored in plant bioprospecting, possess specialized mechanisms that allow them to complete their life cycle under high salinity conditions (≥ 200 mM NaCl). These species constitute approximately 1% to 2% of the world’s flora and are distributed across coastal, mangrove and saline agricultural regions. Upon consistent ionic and osmotic stress, these plants accumulate secondary metabolites like alkaloids, flavonoids, terpenoids, phenolics and sulphated polysaccharides. With global salinization projected at 2050, over 50% of world’s cultivable land may be affected by soil salinization. Therefore, halophytes represent an ecologically important and pharmacologically unexplored source of bioactive metabolites rather than a traditional natural products pipeline. Unlike previous reviews focusing on salt tolerance physiology, this review integrates molecular regulation, multi-omics, microbiome interactions and synthetic biology into a single framework for translational bioprospecting. The molecular framework of salt stress-induced secondary metabolite biosynthesis, epigenomics, transcriptomics, proteomics, metabolomics and fluxomics evidence, and halophytes-associated microbiome as a source for bioprospecting, biotechnological strategies for exploiting the secondary metabolites, such as in vitro tissue culture, hairy root culture, genetic and metabolic engineering. Several research gaps have been identified, including the lack of standardized protocols, a shortage of in vivo validations, and fragmented multi-omics integration.