Microbial Models and Salt Stress Tolerance in Plants

Serrano, Ramón; Gaxiola, Roberto A.

doi:10.1080/07352689409701911

Cited by 184 publications

(33 citation statements)

References 156 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yeast achieves salt tolerance mainly through exclusion of toxic sodium ions at the plasma membrane through the operation of a plasma membrane Na ϩ pump and Na ϩ /H ϩ antiporter (23,47). A disruption of these plasma membrane Na ϩ efflux systems results in a dramatic increase in the intracellular Na ϩ /K ϩ ratio when the cells are grown in the presence of NaCl (48,49).…”

Section: Fig 7 Subcellular Fractionation Of Lenhx2 In Tomato Cellsmentioning

confidence: 99%

A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

Venema

Belver

Marín-Manzano

et al. 2003

Journal of Biological Chemistry

137

117

View full text Add to dashboard Cite

With concentrations between 0.1 and 0.2 M, potassium is the most abundant cation in plant cells. The main pool of potassium inside the plant cell is in the vacuole. The function of potassium in this organelle is thought to be purely biophysical; to generate cell turgor to drive cell expansion (1). Under conditions that limit K ϩ availability, the role of K ϩ in the vacuole can be replaced by other ions like Na ϩ , as has been reported to occur under conditions of salt stress (2). Vacuolar concentrations thus vary from high (200 mM) to low (20 mM), suggesting the existence of active K ϩ import and export mechanisms at the vacuolar membrane (3).The role and concentration of K ϩ in other endomembrane organelles in plants are largely unknown. Apart from a specific K ϩ requirement, secondary ion transporters might rely on K ϩ for pH regulation in these organelles. It was shown that apart from the vacuole, V-type H ϩ -transporting ATPase is found in various membranes of the secretory system where vesicle acidification is important for ligand-receptor binding and protein modification, trafficking, and sorting (4, 5). In animal cells, the pH gradient from neutral to acidic along organelles from both the secretory and endocytic pathways is suggested to be under tight control by the operation of secondary ion transporters providing proton leak pathways (6,7,8). Second, solute uptake energized by the pH gradient might be required to generate the osmotic pressure needed for vesicle fusion (5). In view of the abundance of K ϩ in the cell, K ϩ /H ϩ exchangers are likely candidates to be involved in pH and osmoregulation of intracellular compartments as well as active uptake of K ϩ into vacuoles (3) although the biochemical evidence for the existence of such antiporters is scarce (9, 10).In contrast to the limited information available on K ϩ /H ϩ antiporters, many reports have indicated the existence of vacuolar Na ϩ /H ϩ antiporters in plants (11). The first vacuolar Na ϩ /H ϩ exchanger AtNHX1 was identified recently (12), and it was shown that overexpression of this gene in plants enhances salt tolerance (13,14,15). A family of six genes was identified in Arabidopsis (AtNHX1 to AtNHX6) that shows sequence homology to mammalian and yeast NHE or NHX exchangers (16,17). It was demonstrated however that AtNHX1 could catalyze both Na ϩ /H ϩ and K ϩ /H ϩ exchange (14, 18). A similar ion specificity was reported for the human NHE7 isoform. It was shown that this isoform is expressed in the trans-Golgi network, indicating that regulation of pH and ionic composition of intracellular compartments by K ϩ /H ϩ or Na ϩ /H ϩ exchange is an important task of these antiporters (7). This notion was strengthened by the observation that the NHX1 protein is essential for osmotolerance and endosomal protein trafficking in yeast (19,20). Indeed, plant NHX genes were shown not only to be involved in salinity tolerance, but also in vacuolar pH regulation (21,22), and to be induced by NaCl, KCl, and osmotic stress (12,16,(23)(24)(25)(26), or even h...

show abstract

Section: Fig 7 Subcellular Fractionation Of Lenhx2 In Tomato Cellsmentioning

confidence: 99%

A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

Venema

Belver

Marín-Manzano

et al. 2003

Journal of Biological Chemistry

137

117

View full text Add to dashboard Cite

show abstract

“…Research with Saccharomyces cerevisiae has been extremely valuable in dissecting the regulatory mechanisms of ion homeostasis and salt tolerance (6)(7)(8). The cellular mechanisms of plant salt tolerance are thought to be similar to those in yeast in which signaling through a protein phosphatase, calcineurin, modulates the expression and activities of Na ϩ and K ϩ transporters to maintain low Na ϩ and high K ϩ concentrations in the cytoplasm (6,9,10).…”

mentioning

confidence: 99%

The Arabidopsis SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3

Halfter¹

2000

Proceedings of the National Academy of Sciences

307

349

View full text Add to dashboard Cite

The Arabidopsis thaliana SOS2 and SOS3 genes are required for intracellular Na ؉ and K ؉ homeostasis and plant tolerance to high Na ؉ and low K ؉ environments. SOS3 is an EF hand type calciumbinding protein having sequence similarities with animal neuronal calcium sensors and the yeast calcineurin B. SOS2 is a serine͞ threonine protein kinase in the SNF1͞AMPK family. We report here that SOS3 physically interacts with and activates SOS2 protein kinase. Genetically, sos2sos3 double mutant analysis indicates that SOS2 and SOS3 function in the same pathway. Biochemically, SOS2 interacts with SOS3 in the yeast two-hybrid system and in vitro binding assays. The interaction is mediated by the C-terminal regulatory domain of SOS2. SOS3 activates SOS2 protein kinase activity in a Ca 2؉ -dependent manner. Therefore, SOS3 and SOS2 define a novel regulatory pathway important for the control of intracellular ion homeostasis and salt tolerance in plants.

show abstract

“…To meet this challenge, it will be necessary to increase the productivity of land already under cultivation and to regain the use of arable land lost to scarce water supplies (1,2). Transgenic crops engineered to tolerate some measure of drought could significantly increase yields for many developing countries and help to alleviate an increasingly imminent threat of famine (3).…”

mentioning

confidence: 99%

Up-regulation of a H ⁺ -pyrophosphatase (H ⁺ -PPase) as a strategy to engineer drought-resistant crop plants

Park

Pittman

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

237

168

View full text Add to dashboard Cite

Engineering drought -resistant crop plants is a critically important objective. Overexpression of the vacuolar H ؉ -pyrophosphatase (H ؉ -PPase) AVP1 in the model plant Arabidopsis thaliana results in enhanced performance under soil water deficits. Recent work demonstrates that AVP1 plays an important role in root development through the facilitation of auxin fluxes. With the objective of improving crop performance, we expressed AVP1 in a commercial cultivar of tomato. This approach resulted in (i) greater pyrophosphate-driven cation transport into root vacuolar fractions, (ii) increased root biomass, and (iii) enhanced recovery of plants from an episode of soil water deficit stress. More robust root systems allowed transgenic tomato plants to take up greater amounts of water during the imposed water deficit stress, resulting in a more favorable plant water status and less injury. This study documents a general strategy for improving drought resistance of crops.root development ͉ biotechnology ͉ water deficit stress ͉ tomato

show abstract

Microbial Models and Salt Stress Tolerance in Plants

Cited by 184 publications

References 156 publications

A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

The Arabidopsis SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3

Up-regulation of a H ⁺ -pyrophosphatase (H ⁺ -PPase) as a strategy to engineer drought-resistant crop plants

Contact Info

Product

Resources

About

Microbial Models and Salt Stress Tolerance in Plants

Cited by 184 publications

References 156 publications

A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

The Arabidopsis SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3

Up-regulation of a H + -pyrophosphatase (H + -PPase) as a strategy to engineer drought-resistant crop plants

Contact Info

Product

Resources

About

Up-regulation of a H ⁺ -pyrophosphatase (H ⁺ -PPase) as a strategy to engineer drought-resistant crop plants