Integrative Control Between Proton Pumps and SOS1 Antiporters in Roots is Crucial for Maintaining Low Na+ Accumulation and Salt Tolerance in Ammonium-Supplied Sorghum bicolor.
An effective strategy for re-establishing K+ and Na+ homeostasis is a challenge for the improvement of plant performance in saline soil. Specifically, attempts to understand the mechanisms of Na+ extrusion from plant cells, the control of Na+ loading in the xylem and the partitioning of the accumulated Na+ between different plant organs are ongoing. Our goal was to provide insight into how an external nitrogen source affects Na+ accumulation in Sorghum bicolor under saline conditions. The NH4+ supply improved the salt tolerance of the plant by restricting Na+ accumulation and improving the K+/Na+ homeostasis in shoots, which was consistent with the high activity and expression of Na+/H+ antiporters and proton pumps in the plasma membrane and vacuoles in the roots, resulting in low Na+ loading in the xylem. Conversely, although NO3--grown plants had exclusion and sequestration mechanisms for Na+, these responses were not sufficient to reduce Na+ accumulation. In conclusion, NH4+ acts as an efficient signal to activate co-ordinately responses involved in the regulation of Na+ homeostasis in sorghum plants under salt stress, which leads to salt tolerance.
Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal/CNPq), Universidade Federal do Ceará, 60440-554, Fortaleza, Ceará, Brazil.
Rafael de Souza
RS
Miranda
Departamento de Fitotecnia, Universidade Federal do Ceará, 60440-554, Fortaleza, Ceará, Brazil.
Rosilene Oliveira
RO
Mesquita
Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal/CNPq), Universidade Federal do Ceará, 60440-554, Fortaleza, Ceará, Brazil.
José Hélio
JH
Costa
Centro de Ciências Agrárias e da Biodiversidade, Universidade Federal do Cariri, 63133-610, Crato, Ceará, Brazil.
Juan Carlos
JC
Alvarez-Pizarro
Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal/CNPq), Universidade Federal do Ceará, 60440-554, Fortaleza, Ceará, Brazil.
José Tarquinio
JT
Prisco
Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal/CNPq), Universidade Federal do Ceará, 60440-554, Fortaleza, Ceará, Brazil.
Enéas
E
Gomes-Filho
D000251:Adenosine Triphosphatases / Q000032:analysis; D064751:Ammonium Compounds / Q000378:metabolism*; D017920:Antiporters / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D006706:Homeostasis; D009584:Nitrogen / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D017494:Proton Pumps / Q000378:metabolism*; D055049:Salt Tolerance / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D045868:Sorghum / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism; D052584:Xylem / Q000378:metabolism
D064751:Ammonium Compounds; D017920:Antiporters; D027682:Cation Transport Proteins; D017494:Proton Pumps; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride; D012964:Sodium; D000251:Adenosine Triphosphatases; D009584:Nitrogen; D011188:Potassium
K+/Na+ homeostasis; Na+/H+ antiporter; Nitrogen nutrition; Proton pump; Salt stress; Sorghum