Myo-inositol phosphate synthase (MIPS) as a molecular hub: Regulating plant growth and stress adaptation

Myo-inositol phosphate synthase (MIPS) is a highly conserved enzyme found across a broad spectrum of organisms, from archaea to higher plants and animals. It catalyzes the first and rate-limiting step in the biosynthesis of myo-inositol (MI), a key molecule in plant metabolism. MI and its derivatives play essential roles in numerous biological processes such as phosphorus storage, auxin transport, cell wall formation, signal transduction, and programmed cell death. MIPS activity directly influences MI levels, affecting seed germination, embryogenesis, and stress tolerance through phosphate and mineral mobilization. MIPS is also central to regulating phytic acid accumulation in seeds, and transgenic silencing has shown potential for improving mineral bioavailability. Multiple isoforms of MIPS exhibit distinct spatial and temporal expression patterns across plant species. Gain-of-function and loss-of-function studies have extensively demonstrated that MIPS plays a vital role in regulating plant responses to abiotic and biotic stresses. Notably, emerging evidence points to a crucial role of MIPS in photoperiodic growth under long-day conditions. Despite the expanding knowledge on MIPS, a review synthesizing its diverse roles in plant physiology and development has been notably lacking. This review addresses this critical gap by providing an up-to-date, in-depth analysis of MIPS's multifaceted functions and regulatory mechanisms.