Unravelling the strategies used by the wild tomato species Solanum pennellii to confront salt stress: From leaf anatomical adaptations to molecular responses

•Wild tomato species are of great interest in the study of salt tolerance mechanisms.•Salinity adaptation of S. pennellii depends on coordinated anatomical, physiological and molecular strategies.•Leaf anatomical changes are crucial in the adaptation of S. pennellii to salinity.•Improved water homeostasis of S. pennellii is related to its higher salt tolerance.•S. pennellii shows differential expression of key genes involved in Na+ homeostasis.