Assessment of salt tolerance in phytodesalination candidates: Two varieties of Fimbristylis—F. ferruginea and F. tenuicula

Abstract

Phytodesalination, an environmentally sustainable solution for saline soil challenges, involves identifying salt-tolerant plants. This study meticulously examined Fimbristylis ferruginea and Fimbristylis tenuicula near the underground salt dome in Khon Kaen, Thailand, revealing unique physicochemical soil properties, morphology, metabolomic responses, and ionic sequestration mechanisms. Despite F. ferruginea’s lower EC_e (21.79 vs. 41.46 dS m⁻¹ for F. tenuicula), it excelled in sodium sequestration (504.42 g kg DW⁻¹ vs. 246.32 g kg DW⁻¹). Fimbristylis ferruginea’s roots efficiently locked sodium, facilitated by cyanidin, pelargonidin, and proline—compatible solutes crucial under salinity stress. Conversely, F. tenuicula, within the same genus and environment, responded to salinity stress by elongating roots and stems, enhancing salt storage, and increasing chlorophyll a content. Bioconcentration factor and translocation factor calculations designated F. ferruginea for phytostabilization and F. tenuicula for phytoextraction. This research emphasizes the assessment of salt tolerance in two Fimbristylis species, serving as natural salt reservoirs with low-cost implications. Remarkably, F. ferruginea dominated, storing up to 50% sodium in its biomass.