Tag: Christian Zörb

Advances in stomata research especially for crops growing at hyperosmotic saline environments

Impact of nutritional imbalance on guard cell metabolism and stomata regulation under saline hyperosmotic conditions

Zörb C., Franzisky B. L., Lehr P. P., Kosch R., Altenbuchinger M., Geilgus C.-M. (2022)

Christian Zörb, Bastian Leander Franzisky, Patrick Pascal Lehr, Robin Kosch, Michael Altenbuchinger, Christoph-Martin Geilfus,

===

Advances in Botanical Research 103: 123-186 – DOI: 10.1016/bs.abr.2022.02.011 –

https://www.researchgate.net/publication/359122810_Impact_of_nutritional_imbalance_on_guard_cell_metabolism_and_stomata_regulation_under_saline_hyperosmotic_conditions

Abstract

Stomata closure under adverse conditions leads to reduced CO2 assimilation and yield penalty. This review focuses on advances in stomata research especially for crops growing at hyperosmotic saline environments. Possible new aspects of nutritional imbalances under saline hyperosmotic conditions on guard cell metabolism which were deduced from the recent literature were focused. In particular possible effects of high Na⁺ concentration on GABA shunt which may regulate tonoplast anion channel activity and thus stomatal aperture were discussed. The extent to which stress-induced GABA production influences stomatal behavior in interaction with other signaling pathways remains an interesting topic that requires further research. Another example is magnesium and its role in stomata regulation. Up to date understanding about the relevance of a salinity-induced reduction of magnesium for stomatal opening is rudimentary. Few reports have linked the magnesium-nutritional status to transpiration, doing so by contemplating a role of mesophyll-derived CO2- or sugar-signals. Further research is needed to test whether stomatal opening is delayed when photosynthetic electron transport or the ability to extrude protons are impaired due to salinity-induced deficiency of magnesium. Furthermore, we discuss an opinion that sulfur might be involved in guard cell regulation in crop plants. Our article may provoke further research to broaden the knowledge of the underlying guard cell physiology.

Chloride‐inducible transient apoplastic alkalinizations induce stomata closure

 

 

Chloride‐inducible transient apoplastic alkalinizations induce stomata closure by controlling abscisic acid distribution between leaf apoplast and guard cells in salt‐stressed Vicia faba

by Geilfus C._M., Mithöfer A., Ludwig‐Müller J., Zörb C., Muehling K. H. (xxxx)

Christoph‐Martin Geilfus, Axel Mithöfer, Jutta Ludwig‐Müller, Christian Zörb, Karl H. Muehling

Axel Mithöfer, Department Bioorganic Chemistry, Max Planck Institute for Chemical Ecology

Jutta Ludwig‐Müller, Institut für Botanik, Technische Universität Dresden

Christian Zörb, Quality of Plant Products, University Hohenheim

Karl H. Muehling, Institute of Plant Nutrition and Soil Science, Christian Albrechts University

———————-

in New Phytologist 208(3): 803 – 816 – DOI10.1111/nph.13507 –

https://www.infona.pl/resource/bwmeta1.element.wiley-nph-v-208-i-3-nph13507

Abstract

  • Chloride stress causes the leaf apoplast transiently to alkalize, an event that is presumed to contribute to the ability of plants to adapt to saline conditions. However, the initiation of coordinated processes downstream of the alkalinization is unknown. We hypothesize that chloride‐inducible pH dynamics are a key chemical feature modulating the compartmental distribution of abscisic acid (ABA) and, as a consequence, affecting stomata aperture.
  • Apoplastic pH and stomata aperture dynamics in intact Vicia faba leaves were monitored by microscopy‐based ratio imaging and porometric measurements of stomatal conductance. ABA concentrations in leaf apoplast and guard cells were compared with pH dynamics by gas‐chromatography‐mass‐spectrometry (GC‐MS) and liquid‐chromatography–tandem‐mass spectrometry (LC‐MS/MS).
  • Results demonstrate that, upon chloride addition to roots, an alkalizing factor that initiates the pH dynamic propagates from root to leaf in a way similar to xylem‐distributed water. In leaves, it induces a systemic transient apoplastic alkalinization that causes apoplastic ABA concentration to increase, followed by an elevation of endogenous guard cell ABA.
  • We conclude that the transient alkalinization, which is a remote effect of chloride stress, modulates the compartmental distribution of ABA between the leaf apoplast and the guard cells and, in this way, is instrumental in inducing stomata closure during the beginning of salinity.