The Effect of AtHKT1;1 or AtSOS1 Mutation on the Expressions of Na⁺ or K⁺ Transporter Genes and Ion Homeostasis in Arabidopsis thaliana under Salt Stress

• Published in: International journal of molecular sciences Vol. 20; no. 5; p. 1085
• Main Authors: Wang, Qian, Guan, Chao, Wang, Pei, Ma, Qing, Bao, Ai-Ke, Zhang, Jin-Lin, Wang, Suo-Min
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02-03-2019; MDPI
• Subjects: Abiotic stress; Agricultural production; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; athkt1; atsos1; Calcium; Calcium ions; Cation Transport Proteins - genetics; Cation Transport Proteins - metabolism; Depolarization; Efflux; Gene Expression Regulation, Plant; Homeostasis; Membrane potential; Membranes; Mutation; Na+; Na+/H+-exchanging ATPase; Potassium Channels - genetics; Potassium Channels - metabolism; Salinity; Salinity tolerance; Salt; Salt Stress; Shaker Superfamily of Potassium Channels - genetics; Shaker Superfamily of Potassium Channels - metabolism; Sodium; Sodium-Hydrogen Exchangers - genetics; Sodium-Hydrogen Exchangers - metabolism; Stress concentration; Symporters - genetics; Symporters - metabolism; Transport; Xylem; Arabidopsis thaliana; 1; atsos1; Na+; athkt1; salt stress; K
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20051085

HKT1 and SOS1 are two key Na⁺ transporters that modulate salt tolerance in plants. Although much is known about the respective functions of HKT1 and SOS1 under salt conditions, few studies have examined the effects of
and
mutations on the expression of other important Na⁺ and K⁺ transporter genes. This study investigated the physiological parameters and expression profiles of
,
,
,
,
,
, and
in wild-type (WT) and
and
mutants of
under 25 mM NaCl. We found that
mutation induced a significant decrease in transcripts of
(by 56⁻62% at 6⁻24 h),
(by 36⁻78% at 6⁻24 h), and
(by 31⁻53% at 6⁻24 h) in the roots compared with WT. This led to an increase in Na⁺ accumulation in the roots, a decrease in K⁺ uptake and transportation, and finally resulted in suppression of plant growth.
loss induced a 39⁻76% (6⁻24 h) decrease and a 27⁻32% (6⁻24 h) increase in transcripts of
and
, respectively, in the roots compared with WT. At the same time, 25 mM NaCl decreased the net selective transport capacity for K⁺ over Na⁺ by 92% in the
roots compared with the WT roots. Consequently, Na⁺ was loaded into the xylem and delivered to the shoots, whereas K⁺ transport was restricted. The results indicate that AtHKT1;1 and AtSOS1 not only mediate Na⁺ transport but also control ion uptake and the spatial distribution of Na⁺ and K⁺ by cooperatively regulating the expression levels of relevant Na⁺ and K⁺ transporter genes, ultimately regulating plant growth under salt stress.