TY - JOUR
T1 - Soil bacteria confer plant salt tolerance by tissue-specific regulation of the sodium transporter HKT1
AU - Zhang, Huiming
AU - Kim, Mi Seong
AU - Sun, Yan
AU - Dowd, Scot E.
AU - Shi, Huazhong
AU - Paré, Paul W.
PY - 2008/6
Y1 - 2008/6
N2 - Elevated sodium (Na+) decreases plant growth and, thereby, agricultural productivity. The ion transporter high-affinity K+ transporter (HKT)1 controls Na+ import in roots, yet dysfunction or overexpression of HKT1 fails to increase salt tolerance, raising questions as to HKT1's role in regulating Na+ homeostasis. Here, we report that tissuespecific regulation of HKT1 by the soil bacterium Bacillus subtilis GB03 confers salt tolerance in Arabidopsis thaliana. Under salt stress (100 mM NaCl), GB03 concurrently down- and upregulates HKT1 expression in roots and shoots, respectively, resulting in lower Na+ accumulation throughout the plant compared with controls. Consistent with HKT1 participation in GB03-induced salt tolerance, GB03 fails to rescue salt-stressed athkt1 mutants from stunted foliar growth and elevated total Na+ whereas salt-stressed Na+ export mutants sos3 show GB03-induced salt tolerance with enhanced shoot and root growth as well as reduced total Na+. These results demonstrate that tissue-specific regulation of HKT1 is critical for managing Na+ homeostasis in salt-stressed plants, as well as underscore the breadth and sophistication of plant-microbe interactions.
AB - Elevated sodium (Na+) decreases plant growth and, thereby, agricultural productivity. The ion transporter high-affinity K+ transporter (HKT)1 controls Na+ import in roots, yet dysfunction or overexpression of HKT1 fails to increase salt tolerance, raising questions as to HKT1's role in regulating Na+ homeostasis. Here, we report that tissuespecific regulation of HKT1 by the soil bacterium Bacillus subtilis GB03 confers salt tolerance in Arabidopsis thaliana. Under salt stress (100 mM NaCl), GB03 concurrently down- and upregulates HKT1 expression in roots and shoots, respectively, resulting in lower Na+ accumulation throughout the plant compared with controls. Consistent with HKT1 participation in GB03-induced salt tolerance, GB03 fails to rescue salt-stressed athkt1 mutants from stunted foliar growth and elevated total Na+ whereas salt-stressed Na+ export mutants sos3 show GB03-induced salt tolerance with enhanced shoot and root growth as well as reduced total Na+. These results demonstrate that tissue-specific regulation of HKT1 is critical for managing Na+ homeostasis in salt-stressed plants, as well as underscore the breadth and sophistication of plant-microbe interactions.
UR - http://www.scopus.com/inward/record.url?scp=46449130260&partnerID=8YFLogxK
U2 - 10.1094/MPMI-21-6-0737
DO - 10.1094/MPMI-21-6-0737
M3 - Article
C2 - 18624638
AN - SCOPUS:46449130260
VL - 21
SP - 737
EP - 744
JO - Molecular Plant-Microbe Interactions
JF - Molecular Plant-Microbe Interactions
SN - 0894-0282
IS - 6
ER -