151
|
The Complex Fine-Tuning of K⁺ Fluxes in Plants in Relation to Osmotic and Ionic Abiotic Stresses. Int J Mol Sci 2019; 20:ijms20030715. [PMID: 30736441 PMCID: PMC6387338 DOI: 10.3390/ijms20030715] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/17/2019] [Accepted: 01/29/2019] [Indexed: 12/19/2022] Open
Abstract
As the main cation in plant cells, potassium plays an essential role in adaptive responses, especially through its involvement in osmotic pressure and membrane potential adjustments. K+ homeostasis must, therefore, be finely controlled. As a result of different abiotic stresses, especially those resulting from global warming, K⁺ fluxes and plant distribution of this ion are disturbed. The hormone abscisic acid (ABA) is a key player in responses to these climate stresses. It triggers signaling cascades that ultimately lead to modulation of the activities of K⁺ channels and transporters. After a brief overview of transcriptional changes induced by abiotic stresses, this review deals with the post-translational molecular mechanisms in different plant organs, in Arabidopsis and species of agronomical interest, triggering changes in K⁺ uptake from the soil, K⁺ transport and accumulation throughout the plant, and stomatal regulation. These modifications involve phosphorylation/dephosphorylation mechanisms, modifications of targeting, and interactions with regulatory partner proteins. Interestingly, many signaling pathways are common to K⁺ and Cl-/NO3- counter-ion transport systems. These cross-talks are also addressed.
Collapse
|
152
|
Gvozdevaite A, Oliveras I, Domingues TF, Peprah T, Boakye M, Afriyie L, da Silva Peixoto K, de Farias J, Almeida de Oliveira E, Almeida Farias CC, Dos Santos Prestes NCC, Neyret M, Moore S, Schwantes Marimon B, Marimon Junior BH, Adu-Bredu S, Malhi Y. Leaf-level photosynthetic capacity dynamics in relation to soil and foliar nutrients along forest-savanna boundaries in Ghana and Brazil. TREE PHYSIOLOGY 2018; 38:1912-1925. [PMID: 30388271 DOI: 10.1093/treephys/tpy117] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
Forest-savanna boundaries extend across large parts of the tropics but the variability of photosynthetic capacity in relation to soil and foliar nutrients across these transition zones is poorly understood. For this reason, we compared photosynthetic capacity (maximum rate of carboxylation of Rubisco at 25 C° (Vcmax25), leaf mass, nitrogen (N), phosphorus (P) and potassium (K) per unit leaf area (LMA, Narea, Parea and Karea, respectively), in relation to respective soil nutrients from 89 species at seven sites along forest-savanna ecotones in Ghana and Brazil. Contrary to our expectations, edaphic conditions were not reflected in foliar nutrient concentrations but LMA was slightly higher in lower fertility soils. Overall, each vegetation type within the ecotones demonstrated idiosyncratic and generally weak relationships between Vcmax25 and Narea, Parea and Karea. Species varied significantly in their Vcmax25 ↔ Narea relationship due to reduced investment of total Narea in photosynthetic machinery with increasing LMA. We suggest that studied species in the forest-savanna ecotones do not maximize Vcmax25 per given total Narea due to adaptation to intermittent water availability. Our findings have implications for global modeling of Vcmax25 and forest-savanna ecotone productivity.
Collapse
Affiliation(s)
- Agne Gvozdevaite
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Imma Oliveras
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Tomas Ferreira Domingues
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Theresa Peprah
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, Kumasi, KNUST, Ghana
| | - Mickey Boakye
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, Kumasi, KNUST, Ghana
| | - Lydia Afriyie
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, Kumasi, KNUST, Ghana
| | - Karine da Silva Peixoto
- Departamento de Ciências Biológicas Nova Xavantina, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Josenilton de Farias
- Departamento de Ciências Biológicas Nova Xavantina, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Edmar Almeida de Oliveira
- Departamento de Ciências Biológicas Nova Xavantina, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | | | | | - Margot Neyret
- Centre IRD France Nord - iEES Paris, 32, av. Henri Varagnat BONDY cedex, France
| | - Sam Moore
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Beatriz Schwantes Marimon
- Departamento de Ciências Biológicas Nova Xavantina, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Ben Hur Marimon Junior
- Departamento de Ciências Biológicas Nova Xavantina, Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brazil
| | - Stephen Adu-Bredu
- Forestry Research Institute of Ghana, Council for Scientific and Industrial Research, Kumasi, KNUST, Ghana
| | - Yadvinder Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK
| |
Collapse
|