Sesuvium portulacastrum maintains adequate gas exchange, pigment composition, and thylakoid proteins under moderate and high salinity

Effects of salinity and drought stress on foliar ion concentration, water relations and net gas exchange were evaluated in mature Valencia orange trees (Citrus sinensis [L.] Osbeck) on Poncirus trifoliata L. Raf. (Tri) or sweet orange (C. sinensis, Swt) rootstocks at Dareton on the Murray River in New South Wales. Trees had been irrigated with river water which averaged 4 mol m-3 chloride (Cl-) or with river water plus NaCl to produce 10, 14 or 20 mol m-3 Cl- during the previous 3 years. Chloride concentrations in leaves of trees on Tri were significantly higher than those on Swt rootstock. Foliar sodium (Na+) and Cl- concentrations increased and potassium (K+) concentrations decreased as leaves aged, especially under irrigation with 20 mol m-3 Cl-. Leaf osmotic potential was reduced as leaves matured and also by high salinity so that reductions in leaf water potential were offset. Mature leaves had a lower stomatal conductances and higher water use efficiency than young leaves. After 2 months of withholding irrigation water, leaves of low salinity trees on Tri rootstock had higher rates of net gas exchange than those on Swt rootstock, indicating rootstock-affected drought tolerance. Previous treatment with 20 mol m-3 Cl- lowered leaf area index of all trees by more than 50%, and resulted in greater reserves of soil moisture under partially defoliated trees after the drought treatment. This was reflected in more rapid evening recovery of leaf water potential and less severe reductions in net gas exchange after drought treatment in high salinity trees on Swt rootstock. High salinity plus drought stress increased Na+ content of leaves on Swt, but not on Tri rootstocks. Drought stress had no additive effect, with high salinity on osmotic potential of mature leaves. Thus, the salinity-induced reduction in leaf area appeared to be independent of the Cl- exclusion capability of the rootstock and decreased the effects of subsequent drought stress on leaf water relations and net gas exchange.

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Relationships between gas-exchange characteristics and stomatal structural modifications in some desert grasses under high salinity

Photosynthetica ◽

10.1007/s11099-010-0059-7 ◽

2010 ◽

Vol 48 (3) ◽

pp. 446-456 ◽

Cited By ~ 15

Author(s):

N. Naz ◽

M. Hameed ◽

M. Ashraf ◽

F. Al-Qurainy ◽

M. Arshad

Keyword(s):

Gas Exchange ◽

High Salinity ◽

Structural Modifications ◽

Gas Exchange Characteristics ◽

Desert Grasses

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Cloning and molecular characterization of fructose-1,6-bisphosphate aldolase gene regulated by high-salinity and drought in Sesuvium portulacastrum

Plant Cell Reports ◽

10.1007/s00299-009-0702-6 ◽

2009 ◽

Vol 28 (6) ◽

pp. 975-984 ◽

Cited By ~ 51

Author(s):

Wei Fan ◽

Zhili Zhang ◽

Yanlin Zhang

Keyword(s):

Molecular Characterization ◽

High Salinity ◽

Sesuvium Portulacastrum ◽

Fructose 1,6 Bisphosphate ◽

Aldolase Gene

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Growth and Gas Exchange Responses of Olive Tree Cuttings to Elevated CO2 Concentration under Saline Conditions

HortScience ◽

10.21273/hortsci.39.4.771a ◽

2004 ◽

Vol 39 (4) ◽

pp. 771A-771

Author(s):

J.C. Melgar ◽

J. Dunlop ◽

J.P. Syvertsen* ◽

F. García-Sánchez

Keyword(s):

Gas Exchange ◽

High Salinity ◽

Growth Parameters ◽

Chloride Concentration ◽

Co2 Concentration ◽

Olive Tree ◽

Sand Culture ◽

Salinity Treatment ◽

Saline Treatment ◽

Leaf Transpiration

Physiological responses of olive cuttings of `Koroneiki' and `Picual' (Olea europaea L.) to zero or high salinity (NaCl 100 mmol·L-1) and to ambient CO2 (380 ppm) or elevated (700 ppm) CO2 concentration were studied in sand culture in greenhouses. Growth parameters, net gas exchange of leaves and leaf chloride concentration were measured after two months of treatment. `Koroneiki' had significantly greater shoot growth and net assimilation of CO2 (Ac) at elevated CO2 than at ambient CO2 but this difference disappeared under salt stress. Growth and Ac of `Picual' did not respond to elevated CO2 regardless of salinity treatment. Stomatal conductance and leaf transpiration were lower at elevated CO2 such that leaf water use efficiency increased at elevated CO2 in both cultivars regardless of saline treatment. The saline treatment increased leaf chloride (Cl) concentration and reduced growth and net gas exchange responses in both cultivars. There was no difference in leaf Cl accumulation between the two varieties. At high salinity, elevated CO2 had little effect on leaf Cl implying that at least in `Koroneiki', Cl accumulation was not closely linked to water uptake.

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Serratia liquefaciens KM4 Improves Salt Stress Tolerance in Maize by Regulating Redox Potential, Ion Homeostasis, Leaf Gas Exchange and Stress-Related Gene Expression

International Journal of Molecular Sciences ◽

10.3390/ijms19113310 ◽

2018 ◽

Vol 19 (11) ◽

pp. 3310 ◽

Cited By ~ 36

Author(s):

Mohamed El-Esawi ◽

Ibrahim Alaraidh ◽

Abdulaziz Alsahli ◽

Saud Alzahrani ◽

Hayssam Ali ◽

...

Keyword(s):

Salt Stress ◽

Gas Exchange ◽

Plant Growth ◽

Stress Tolerance ◽

High Salinity ◽

Leaf Gas Exchange ◽

Ion Homeostasis ◽

Stress Markers ◽

Serratia Liquefaciens ◽

Stress Related Genes

High salinity mitigates crop productivity and quality. Plant growth-promoting soil rhizobacteria (PGPR) improve plant growth and abiotic stress tolerance via mediating various physiological and molecular mechanisms. This study investigated the effects of the PGPR strain Serratia liquefaciens KM4 on the growth and physiological and molecular responsiveness of maize (Zea mays L.) plants under salinity stress (0, 80, and 160 mM NaCl). High salinity significantly reduced plant growth and biomass production, nutrient uptake, leaf relative water content, pigment content, leaf gas exchange attributes, and total flavonoid and phenolic contents in maize. However, osmolyte content (e.g., soluble proteins, proline, and free amino acids), oxidative stress markers, and enzymatic and non-enzymatic antioxidants levels were increased in maize under high salinity. On the other hand, Serratia liquefaciens KM4 inoculation significantly reduced oxidative stress markers, but increased the maize growth and biomass production along with better leaf gas exchange, osmoregulation, antioxidant defense systems, and nutrient uptake under salt stress. Moreover, it was found that all these improvements were accompanied with the upregulation of stress-related genes (APX, CAT, SOD, RBCS, RBCL, H+-PPase, HKT1, and NHX1), and downregulation of the key gene in ABA biosynthesis (NCED). Taken together, the results demonstrate the beneficial role of Serratia liquefaciens KM4 in improving plant growth and salt stress tolerance in maize by regulating ion homeostasis, redox potential, leaf gas exchange, and stress-related genes expression.

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