Abscisic Acid Signal off the STARTing Block

Joshi-Saha, Archana; Valon, Christiane; Leung, Jeffrey

doi:10.1093/mp/ssr055

Cited by 107 publications

(72 citation statements)

References 162 publications

(261 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The impairment of the ABAinduced ROS production in the ost1 mutant could be bypassed by externally applied H 2 O 2 . Recently, it was shown that NADPH oxidases could be SnRK2s' cellular substrates (for review, see Hubbard et al, 2010;Umezawa et al, 2010;Joshi-Saha et al, 2011). A recombinant cytosolic part of one of the Arabidopsis NADPH oxidases, AtrbohF, produced in a bacterial system is phosphorylated by SnRK2.6/OST1 in vitro.…”

Section: Discussionmentioning

confidence: 99%

SNF1-Related Protein Kinases Type 2 Are Involved in Plant Responses to Cadmium Stress

et al. 2012

View full text Add to dashboard Cite

Cadmium ions are notorious environmental pollutants. To adapt to cadmium-induced deleterious effects plants have developed sophisticated defense mechanisms. However, the signaling pathways underlying the plant response to cadmium are still elusive. Our data demonstrate that SnRK2s (for SNF1-related protein kinase2) are transiently activated during cadmium exposure and are involved in the regulation of plant response to this stress. Analysis of tobacco (Nicotiana tabacum) Osmotic StressActivated Protein Kinase activity in tobacco Bright Yellow 2 cells indicates that reactive oxygen species (ROS) and nitric oxide, produced mainly via an L-arginine-dependent process, contribute to the kinase activation in response to cadmium. SnRK2.4 is the closest homolog of tobacco Osmotic Stress-Activated Protein Kinase in Arabidopsis (Arabidopsis thaliana). Comparative analysis of seedling growth of snrk2.4 knockout mutants versus wild-type Arabidopsis suggests that SnRK2.4 is involved in the inhibition of root growth triggered by cadmium; the mutants were more tolerant to the stress. Measurements of the level of three major species of phytochelatins (PCs) in roots of plants exposed to Cd 2+ showed a similar (PC2, PC4) or lower (PC3) concentration in snrk2.4 mutants in comparison to wild-type plants. These results indicate that the enhanced tolerance of the mutants does not result from a difference in the PCs level. Additionally, we have analyzed ROS accumulation in roots subjected to Cd 2+ treatment. Our data show significantly lower Cd 2+ -induced ROS accumulation in the mutants' roots. Concluding, the obtained results indicate that SnRK2s play a role in the regulation of plant tolerance to cadmium, most probably by controlling ROS accumulation triggered by cadmium ions.Cadmium is one of the most toxic soil pollutants. Cadmium ions accumulate in plants and affect, via the food chain, animal and human health. In plants, cadmium is taken up by roots and is transported to aerial organs, leading to chromosomal aberrations, growth reduction, and inhibition of photosynthesis, transpiration, nitrogen metabolism, nutrient and water uptake, eventually causing plant death (for review, see DalCorso et al., 2008). Plants are challenged not only by cadmium ions themselves, but also by Cd 2+ -induced harmful effects including oxidative stress (Schützendübel et al., 2001;Olmos et al., 2003;Cho and Seo, 2005;Sharma and Dietz, 2009). The extent of the detrimental effects on plant growth and metabolism depends on the level of cadmium ions present in the surrounding environment and on the plant's sensitivity to heavy metal stress.Tolerant plants avoid heavy metal uptake and/or induce the expression of genes encoding products involved, directly or indirectly, in heavy metal binding and removal from potentially sensitive sites, by sequestration or efflux (Clemens, 2006). The best-characterized heavy metal binding ligands in plants are thiol-containing compounds metallothioneins and phytochelatins (PCs), whose production is stimulated by Cd 2+. PC...

show abstract

Section: Discussionmentioning

confidence: 99%

SNF1-Related Protein Kinases Type 2 Are Involved in Plant Responses to Cadmium Stress

et al. 2012

View full text Add to dashboard Cite

show abstract

“…This finding indicates that OST1, a protein kinase that regulates SLAC1 activity in the ABA pathway, may be a central integrator of CO 2 and ABA signal transduction in the regulation of SLAC1 in guard cells. While the ABA signal connects to OST1 through ABA receptors and 2C-type protein phosphatases 5,49 , it is not known how the CO 2 signal is linked to OST1. We thus tested the possibility that OST1 may serve as a downstream target of HT1.…”

Section: Rhc1 Is Required For Activation Of the S-type Channelsmentioning

confidence: 99%

A molecular pathway for CO2 response in Arabidopsis guard cells

et al. 2015

View full text Add to dashboard Cite

Increasing carbon dioxide (CO 2 ) levels in the atmosphere have caused global metabolic changes in diverse plant species. CO 2 is not only a carbon donor for photosynthesis but also an environmental signal that regulates stomatal movements and thereby controls plant-water relationships and carbon metabolism. However, the mechanism underlying CO 2 sensing in stomatal guard cells remains unclear. Here we report characterization of Arabidopsis RESISTANT TO HIGH CO 2 (RHC1), a MATE-type transporter that links elevated CO 2 concentration to repression of HT1, a protein kinase that negatively regulates CO 2 -induced stomatal closing. We also show that HT1 phosphorylates and inactivates OST1, a kinase which is essential for the activation of the SLAC1 anion channel and stomatal closing. Combining genetic, biochemical and electrophysiological evidence, we reconstituted the molecular relay from CO 2 to SLAC1 activation, thus establishing a core pathway for CO 2 signalling in plant guard cells.

show abstract

“…Water deficit draws down water potential in all plant tissues and may directly impair turgor pressure in the guard cells surrounding the stomatal pores, thus reducing stomatal aperture (Buckley, 2005;Peak and Mott, 2011). In parallel, accumulation of ABA, whether synthesized in roots Borel et al, 2001) or leaves (Christmann et al, 2005(Christmann et al, , 2007Ikegami et al, 2009;McAdam et al, 2016), directly impacts on guard cells to close stomata (Kim et al, 2010;Joshi-Saha et al, 2011).…”

mentioning

confidence: 99%