Point mutations in the barley HvHAK1 potassium transporter lead to improved K+-nutrition and enhanced resistance to salt stress.
Members of group I KT-HAK-KUP transporters play an important role in K+ acquisition by plant roots, a process that is strongly affected by salt stress. A PCR-based random mutagenesis approach on HvHAK1 allowed identification of V366I and R591C substitutions, which confer enhanced K+-capture, and improved NaCl, LiCl and NH4Cl tolerance, to yeast cells. Improved K+-capture was linked to an enhanced Vmax. Results reveal an intrinsic protective effect of K+, and assign an important role to the 8th transmembrane domain, as well as the C-terminus, in determining the maximum capacity for the transport of K+ in KT-HAK-KUP transporters.
Mangano
Silvina
S
Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto Tecnológico de Chascomús, Camino Circunvalación km 6, Chascomús, Provincia de Buenos Aires 7130, Argentina.
Silberstein
Susana
S
Santa-María
Guillermo E
GE
D019943:Amino Acid Substitution; D001120:Arginine / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D017136:Ion Transport; D007532:Isoleucine / Q000235:genetics / Q000378:metabolism; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017354:Point Mutation; D011188:Potassium / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D054712:Salinity; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism; D014633:Valine / Q000235:genetics / Q000378:metabolism
D027682:Cation Transport Proteins; C110544:HAK2 protein, Hordeum vulgare; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins; D007532:Isoleucine; C068664:TRK1 protein, S cerevisiae; D012965:Sodium Chloride; D001120:Arginine; D012964:Sodium; D014633:Valine; D003545:Cysteine; D011188:Potassium