The endophytic fungus Serendipita indica helps to reduce Na+ accumulation in plants exposed to salinity

Here is an increasing need to search for alternative strategies to improve tolerance to plant salinity. One of them is to give greater prominence to the microbiota that lives associated with plant roots, specifically the endophytic fungi, which improve the response of the plants to that stress condition.


It has been described that the endophytic fungus Serendipita indica (formerly called Piriformospora indica) improves the growth and development of plants when exposed to adverse conditions, such as saline environments. However, the mechanism by which Serendipita improves plant growth has not yet been elucidated. In this work we show that Serendipita reduces the Na+ content of Arabidopsis plants when it grows in saline conditions. We also show that a localized and transient alkalinization occurs during the first stages of infection of the plant, a signal that could constitute a response to the infection that regulates further processes. In addition, we describe for the first time the characterization and functional regulation of the two Serendipita ENA ATPases that function as Na+ efflux systems, and that are promising candidates to mediate salt tolerance induced by the fungus and participate in the response of Serendipita at high pH levels.

Co-cultivation with Serendipita indica decreases Na+ contents in Arabidopsis plants growing in saline conditions, both in a parental gl-1 (A) and in a derived salt-sensitive sos1 mutant (B)

During fungal colonization a local alkalinization was induced at the rhizosphere which was detected with the bromocresol purple pH indicator. Plates were imaged at different days post infection (dpi). Bright yellow, pH ( 5.2; deep purple, pH ) 6.8.

Original Paper:

Lanza, M., Haro, R., Conchillo, L.B., Benito, B. 2019. The endophyte Serendipita indica reduces the sodium content of Arabidopsis plants exposed to salt stress: fungal ENA ATPases are expressed and regulated at high pH and during plant co-cultivation in salinity. Environmental Microbiology. DOI: 10.1111/1462-2920.14619