Exploring the Potential of White-Rot Fungi Exudates on the Amelioration of Salinized Soils

Abstract

Soil salinization has a major impact on crop revenue, which may be counteracted by harnessing the microbiota that the soil itself harbors. This study aimed to explore the application of fungi exudates (Trametes versicolor and Pleurotus sajor caju) on the potential relief of salt stress in the performance of Lens culinaris in two different soils (a silvopastoral agroforestry soil and LUFA 2.2). Three salinity levels (8, 16, and 26 mS·cm−1) and three levels of each fungal exudate (1%, 6%, and 12%) were evaluated in a 96-h cross-design experiment. Seed germination was checked daily, and after 96-h, seedling radicle and hypocotyl were measured, along with fresh and dry weights and soil phosphatase activity. The sole application of exudates from neither fungus affected the germination and seedling development of L. culinaris. Salinity alone induced a dose-effect response in all L. culinaris tested endpoints, as expected because conductivities above 8 mS·cm−1 are known to be detrimental for many crop species. Application of exudates to salinized soils improved germination rates at 16 and 26 mS·cm−1 compared to the single respective salinity treatment alone, but mainly in assays carried out in natural soil. In addition, under the same conditions (26 mS·cm−1 and all fungi %), there was an improvement in natural soil acid phosphatase activity. The application of rot fungi exudates demonstrates potential in what might prove to be a sustainable measure to reclaim salinized soils and improve crop productivity, which is consistent with current soil protection policies.