The salt overly sensitive (SOS) pathway: Established and emerging roles

12 páginas.-- 3 figuras.-- 85 referencias

Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive. At the cellular level, the Salt Overly Sensitive (SOS) signaling pathway that comprises SOS3, SOS2, and SOS1 has been proposed to mediate cellular signaling under salt stress, to maintain ion homeostasis. Less well known is how cellularly heterogenous organs couple the salt signals to homeostasis maintenance of different types of cells and to appropriate growth of the entire organ and plant. Recent evidence strongly indicates that different regulatory mechanisms are adopted by roots and shoots in response to salt stress. Several reports have stated that, in roots, the SOS proteins may have novel roles in addition to their functions in sodium homeostasis. SOS3 plays a critical role in plastic development of lateral roots through modulation of auxin gradients and maxima in roots under mild salt conditions. The SOS proteins also play a role in the dynamics of cytoskeleton under stress. These results imply a high complexity of the regulatory networks involved in plant response to salinity. This review focuses on the emerging complexity of the SOS signaling and SOS protein functions, and highlights recent understanding on how the SOS proteins contribute to different responses to salt stress besides ion homeostasis. © 2013 The Author.

We would like to acknowledge support from the National Science Foundation of China (Grant No. 31230050 to X.L.), the National Program on Key Basic Research Project (Grant No. 2009CB118305 to X.L.), the Key Basic Research Project of Applied Basic Research Program of Hebei Province (Grant No. 09960913D to X.L.), the National Transgenic Key Project of MOA (Grant No. 201108002–002 to X.L.), the Ministry of Science and Innovation of Spain (Grant No. BIO2009–08645 to J.M.P.), and the International Exchange Program of the University of Naples ‘Federico II’ to G.B. No conflict of interest declared.

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