Facile Bioself-Assembled Crystals in Plants Promote Photosynthesis and Salt Stress Resistance.

Salty soil is a global problem that has adverse effects on plants. We demonstrate that bioself-assembled molybdenum-sulfur (Mo-S) crystals formed by the foliar application of MoCl5 and cysteine augment the photosynthesis of plants treated with 200 mM salt for 7 days by promoting Ca2+ signal transduction and free radical scavenging. Reductions in glutathione and phytochelatins were attributed to the biosynthesized Mo-S crystals. Plants embedded with the Mo-S crystals and exposed to salty soil exhibited carbon assimilation rates, photosynthesis rates (Fv/Fm), and electron transport rates (ETRs) that were increased by 40%, 63-173%, and 50-78%, respectively, compared with those of plants without Mo-S crystals. Increased compatible osmolyte levels and decreased levels of oxidative damage, stomatal conductance (0.63-0.42 mmol m2 s-1), and transpiration (22.9-15.3 mmol m2 s-1), free radical scavenging, and calcium-dependent protein kinase, and Ca2+ signaling pathway activation were evidenced by transcriptomics and metabolomics. The bioself-assembled crystals originating from ions provide a method for protecting plant development under adverse conditions.