Physiological causes for decreased productivity under high salinity in Boma, a tetraploid Chloris gayana cultivar

2001 ◽  
Vol 52 (9) ◽  
pp. 903 ◽  
Author(s):  
M. de Luca ◽  
L. García Seffino ◽  
K. Grunberg ◽  
M. Salgado ◽  
A. Córrdoba ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
High Salinity ◽  
Leaf Growth ◽  
Salt Gland ◽  
Dry Matter Accumulation ◽  
Rhodes Grass ◽  
Salinity Levels ◽  
Chloris Gayana ◽  
Excretion Rates ◽  
Area Expansion

Rhodes grass (Chloris gayana Kunth) is widely cultivated in the semi-arid tropics and favoured for salt tolerance; nevertheless, productivity decreases significantly under saline conditions, especially in tetraploid cultivars. The purpose of this work was to explore, in the tetraploid cultivar Boma, the physiological causes for such decrease. Experiments were carried out in vegetative plants in the greenhouse. At high salinity (200 mM NaCl), an early reduction in leaf area expansion was observed, and, later, decreased dry matter accumulation, suggesting that the central effect of salinity was a limitation of leaf growth. This was evaluated in 2 closely related Boma clones, exhibiting different degrees of salt tolerance. Growth, ion accumulation and excretion, sugars, and proline concentrations were measured under a range of salt concentrations (0–200 mM NaCl). Differences between the clones in leaf expansion were expressed only at high salinity, but were not associated with differences in water potential or hydraulic conductance in the expanding region. At all salinity levels, the proportion of dry leaves was higher in the clone which also had lower salt gland density and Na excretion rates. Less efficient Na extrusion, associated with high oxidative stress, may be the main cause for leaf senescence and differences in productivity between these clones.

Physiological causes for decreased productivity under high salinity in Boma, a tetraploid Chloris gayana cultivar. II. Oxidative stress

2002 ◽  
Vol 53 (6) ◽  
pp. 663 ◽  
Author(s):  
C. M. Luna ◽  
M. de Luca ◽  
E. Taleisnik
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Enzymes ◽  
Salt Tolerance ◽  
High Salinity ◽  
Salt Gland ◽  
Rhodes Grass ◽  
Chloris Gayana ◽  
Stress Damage ◽  
Chloris Gayana Kunth ◽  
And Oxidative Stress

In tetraploid cultivars of Rhodes grass (Chloris gayana Kunth) productivity decreases significantly under saline conditions. Two closely related clones of cv. Boma (T and S), exhibiting different degrees of salt tolerance, were compared with determine the physiological causes for such decrease. In those clones, salt tolerance was associated with differences in the proportion of dry leaves, salt gland density, Na excretion rate, and oxidative stress damage. The purpose of this paper is to evaluate whether salt tolerance and oxidative stress development in these clones are related to the activity of two antioxidant enzymes. Experiments were conducted in a greenhouse, in winter and summer, in plants treated with 0, 100, or 200 mm NaCl. In the summer, increases in oxidative damage, as determined by malondialdehyde (MDA) concentration, mirrored decreases in CO2 fixation at high salinity, especially in clone S. In clone T, salinity induced higher increases in Fe-SOD (superoxide dismutase) activity in summer-grown plants, and in ascorbate peroxidase (APX) in winter-grown plants. Oxidative stress induced by low paraquat concentration also induced an increase in Fe-SOD in leaf segments of clone T, and APX was less affected in clone T than in clone S. These results suggest that the clones differ in the control of antioxidant enzymes. Nevertheless, leaf death in winter was not related to increases in MDA, indicating that the association between salinity, leaf senescence and oxidatives stress is also influenced by other factors.

scholarly journals Evaluation of Some Rhodes Grass (Chloris gayana) Genotypes for Their Salt Tolerance, Biomass Yield and Nutrient Composition

2019 ◽  
Vol 9 (1) ◽  
pp. 143 ◽  
Author(s):  
Ashenafi Worku Daba ◽  
Asad Sarwar Qureshi ◽  
Bethel Nekir Nisaren
Keyword(s):  
Soil Salinity ◽  
Management Practices ◽  
Germination Percentage ◽  
Soil Salinization ◽  
The Other ◽  
Forage Production ◽  
Rhodes Grass ◽  
Salinity Levels ◽  
Chloris Gayana ◽  
The Impact

The livestock productivity in Ethiopia is seriously constrained by the shortage of fodder due to increasing soil salinization. Therefore, restoration of salt-affected lands into productive soils through salt-tolerant forages and improved irrigation and crop management practices is crucial for enhancing the productivity of the livestock sector in Ethiopia. In this three-year study, pot trials were conducted to evaluate the impact of five different soil salinity levels (i.e., 0, 5, 10, 15, and 20 dS m−1) on plant growth, biomass production, and nutrient quality attributes of three Rhodes grass (Chloris gayana) genotypes (ILRI-6633, ILRI-7384, CV-massaba). Increasing soil salinity negatively affected germination percentage (GP) and mean germination time (MGT) of all genotypes. For all salinity levels, the highest GP was observed for ILRI-6633 and the lowest for CV-massaba. Plant height and chlorophyll content for ILRI-6633 was higher than the other two genotypes. The crude protein (CP) content was higher in low dry matter-producing genotype (ILRI-7384). The performance of ILRI-6633 at all salinity levels was superior to the other two genotypes. CV-massaba genotype performed better under low to medium soil salinity conditions. Therefore, ILRI-6633 and CV-massaba genotypes have excellent potential to increase forage production in salt-affected areas of Ethiopia.

scholarly journals Test the Development in Salt Tolerance in Two Selected Genotypes of Wheat

2012 ◽  
Vol 6 (1) ◽  
pp. 56-61
Author(s):  
Salah M. Hassan ◽  
Majeed D. M. ◽  
Abdo-Wehab M. Whaeb ◽  
Suad M. Majeed ◽  
Ibrahim I. H. Al-Mashhadani
Keyword(s):  
Experimental Design ◽  
Salt Tolerance ◽  
High Salinity ◽  
Plant Breeder ◽  
Breeding Programs ◽  
Important Approach ◽  
Salinity Levels ◽  
Improvement Programs ◽  
Genetic Development ◽  
High Salinity Level

The genetic development for salt tolerance in wheat is very important approach for the plant breeder to overcome salinity problem. Estimation of salt tolerance by two selected genotypes of wheat (4H, N5) was conducted in plastic house as compared with the local cultivars Tamoz 2 to know the development that happened in salt tolerance in these genotypes through the plant breeding programs. The experiment was conducted in pots using four salinity levels (2, 5, 10, 15)ds/m. The experimental design was RCBD with three blocks. Results indicated that both selected genotypes were significantly superior in all measured characters to check cultivar at all salinity levels. There were differences between the two selected genotypes in different traits, but not significant especially at high salinity levels. At these salinity levels, the selected genotypes had more growth in shoots and roots. The differences between the two selected genotypes and the check cultivar in all characters increased in high salinity level. In conclusion, there were genetically improvements with aspect to salt tolerance achieved in selected genotypes through breeding and improvement programs.

scholarly journals Tolerance of castor bean cultivars under salt stress

2016 ◽  
Vol 20 (6) ◽  
pp. 557-563 ◽  
Author(s):  
Francisco V. da S. Sá ◽  
Emanoela P. de Paiva ◽  
Evandro F. de Mesquita ◽  
Antonio M. P. Bertino ◽  
Marcelo A. Barbosa ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Castor Bean ◽  
Dry Matter ◽  
Growth Stage ◽  
Dry Matter Accumulation ◽  
Initial Growth ◽  
Initial Growth Stage ◽  
Salinity Levels

ABSTRACT This study aimed to evaluate the tolerance of castor bean cultivars under salt stress during the initial growth stage. The experiment was set in randomized blocks, in a 5 x 4 factorial scheme, resulting in 20 treatments, 5 salinity levels (0.6-control, 1.2, 1.8, 2.4 and 3.0 dS m-1) and 4 castor bean cultivars (BRS Energy, LA Guarani, BRS Gabriela and IAC 028)] with 3 replicates. At 30 days after sowing, plants were evaluated for growth, dry matter accumulation and salt tolerance. Increased salinity levels in the water used for irrigation reduced the growth of all the studied cultivars. The salt tolerance of the studied castor bean cultivars follows the following order: BRS Energia > BRS Gabriela = IAC 028 > LA Guarani.

scholarly journals Combined Transcriptome and Proteome Analysis to Elucidate Salt Tolerance Strategies of the Halophyte: Panicum antidotale Retz

2021 ◽  
Vol 12 ◽  
Author(s):  
Tabassum Hussain ◽  
Hina Asrar ◽  
Wensheng Zhang ◽  
Bilquees Gul ◽  
Xiaojing Liu
Keyword(s):  
Salt Tolerance ◽  
High Salinity ◽  
Global Analysis ◽  
Proteome Analysis ◽  
Sugar Accumulation ◽  
Saline Stress ◽  
Altered Expression ◽  
Low Salinity ◽  
Salinity Levels ◽  
Panicum Antidotale

Panicum antidotale, a C4 monocot, has the potential to reclaim saline and drylands and to be utilized as fodder and forage. Its adaptability to survive saline stress has been proven with eco-physiological and biochemical studies. However, little is known about its molecular mechanisms of salt tolerance. In this study, an integrated transcriptome and proteome analysis approach, based on RNA sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), was used to identify the said mechanisms. Plants were treated with control (0 mM), low (100 mM), and high (300 mM) sodium chloride (NaCl) treatments to distinguish beneficial and toxic pathways influencing plant biomass. The results indicated differential expression of 3,179 (1,126 upregulated/2,053 downregulated) and 2,172 (898 upregulated/1,274 downregulated) genes (DEGs), and 514 (269 upregulated/245 downregulated) and 836 (494 upregulated/392 downregulated) proteins (DEPs) at 100 and 300 mM NaCl, respectively. Among these, most upregulated genes and proteins were involved in salt resistance strategies such as proline biosynthesis, the antioxidant defense system, ion homeostasis, and sugar accumulation at low salinity levels. On the other hand, the expression of several genes and proteins involved in the respiratory process were downregulated, indicating the inability of plants to meet their energy demands at high salinity levels. Moreover, the impairments in photosynthesis were also evident with the reduced expression of genes regulating the structure of photosystems and increased expression of abscisic acid (ABA) mediated pathways which limits stomatal gas exchange. Similarly, the disturbance in fatty acid metabolism and activation of essential ion transport blockers damaged the integrity of the cell membrane, which was also evident with enhanced malondialdehyde (MDA). Overall, the analysis of pathways revealed that the plant optimal performance at low salinity was related to enhanced metabolism, antioxidative defense, cell growth, and signaling pathways, whereas high salinity inhibited biomass accumulation by altered expression of numerous genes involved in carbon metabolism, signaling, transcription, and translation. The data provided the first global analysis of the mechanisms imparting salt stress tolerance of any halophyte at transcriptome and proteome levels.

The Influence of Salinity on Growth, Water Relations and Photosynthesis in Diplachne fusca (L.) P. Beauv. Ex Roemer & Schultes

1990 ◽  
Vol 17 (6) ◽  
pp. 675 ◽  
Author(s):  
BA Myers ◽  
TF Neales ◽  
MB Jones
Keyword(s):  
Growth Rate ◽  
Water Relations ◽  
Growth Rates ◽  
High Salinity ◽  
Leaf Growth ◽  
Intercellular Co2 Concentration ◽  
Carboxylation Efficiency ◽  
Initial Slope ◽  
Leaf Photosynthesis ◽  
Salinity Levels

The responses to increasing salintiy (in the range 0-420 mol m-3 NaCl) of an Australian accession of the halophytic grass, Diplachne fusca, have been studied in two experiments; in terms of growth, water relations, ion uptake and leaf photosynthesis. Twenty-one to 41 days after salinisation, plant dry weight, leaf area and relative growth rate were decreased at salinities at and above 300 mol m-3. Although salinity in the range 0-200 mol m-3 did not significantly affect growth rate, the highest value was at 200 mol m-3. Towards the end of the sampling period, a recovery of leaf growth rates was greater in plants at salinity levels of 90-200 mol m-3. The salt tolerance of this accession is similar to that reported for other populations of this species. As salinity in the root environment was increased, the osmotic potential of the leaf sap (Ψs) and the difference between leaf water potential and Ψs increased progressively with each harvest. There was no evidence that a lack of a capacity to adjust osmotically was related to the observed inhibition of growth at high salinity levels. It was confirmed that D. fusca possessed a C4 mode of leaf photosynthesis: the maximum assimilation rate (A) observed was high (>50 μmol m-2 s-1), the operating intercellular CO2 concentration (Ci) was approximately 140 μmol mol-1, the initial slope of the A v. CI curve ('carboxylation efficiency') was steep (1.24 μmol m-2 s-1) and the optimum leaf temperature for photosynthesis was approximately 45°C. At high salinities leaf conductance (g) was reduced by 78%. Using an analysis of A v. I and A v. CI relationships, the components of the 'photosynthetic capacity' of the mesophyll reduced by high salinity were Amax, carboxylation efficiency and photorespiration rate. There was no consistent relationship, at three salinity levels, between growth rates and Amax and carboxylation efficiency. It appears unlikely, therefore, that the primary inhibitory effects of salinity on growth are attributable to effects on leaf photosynthetic processes.

Effect of watertable depth and salinity on growth dynamics of Rhodes grass (Chloris gayana)

2016 ◽  
Vol 67 (8) ◽  
pp. 881 ◽  
Author(s):  
Sebastián Chiacchiera ◽  
Nicolás Bertram ◽  
Edith Taleisnik ◽  
Esteban Jobbágy
Keyword(s):  
Growth Dynamics ◽  
Biomass Accumulation ◽  
Shoot Biomass ◽  
Rhodes Grass ◽  
Negative Effect ◽  
Salinity Levels ◽  
Use Efficiency ◽  
Chloris Gayana ◽  
Positive Effect ◽  
Pampas Region

Depending on their depth, watertables can have a positive effect on plants by supplying water, a negative effect by creating waterlogged and/or saline conditions or a neutral effect. Rhodes grass (Chloris gayana), a tropical perennial forage adapted to saline soils, floods and droughts, is a viable choice for the lowlands in the Pampas region of Argentina. The effects of the depth and salt concentration of the watertable on the growth dynamics and biomass accumulation of Rhodes grass were quantified in a greenhouse experiment. The experiment consisted of 10 treatments, resulting from the factorial combination of five watertable depths (25, 75, 125, 175 and 225 cm) and two salt treatments (EC 1.4 and 20.5 dS m–1). The presence of non-saline watertable at a depth of 25 cm produced a 5-fold greater biomass and showed an increase in water consumption of equal magnitude compared with deeper watertables. The increase in shoot biomass was explained primarily by higher tiller and stolon density, which increased 3.3- and 7.7-fold respectively, at watertables that were 25 cm deep compared with deeper treatments. Furthermore, groundwater use efficiency was 30% higher in non-saline watertables at 25 cm depth. Similarly, at this depth, the leaf blades were 50% longer compared with the deepest watertables evaluated. In contrast, the presence of saline watertables at 25 cm depth had a detrimental effect on the production of biomass and its components, whereas the effect at 125 cm and greater depths was neutral. Therefore, Rhodes grass is a species that can take advantage of the widespread shallow watertable environments of the Pampas region as long as the salinity levels are low.

scholarly journals Responses of Rice Growth to Day and Night Temperature and Relative Air Humidity—Leaf Elongation and Assimilation

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Sabine Stuerz ◽  
Folkard Asch
Keyword(s):  
Leaf Area ◽  
Leaf Growth ◽  
Crop Growth ◽  
Air Humidity ◽  
Leaf Elongation ◽  
Night Temperature ◽  
Relative Air Humidity ◽  
Leaf Area Expansion ◽  
Plant Level ◽  
Area Expansion

Predictions of future crop growth and yield under a changing climate require a precise knowledge of plant responses to their environment. Since leaf growth increases the photosynthesizing area of the plant, it occupies a central position during the vegetative phase. Rice is cultivated in diverse ecological zones largely differing in temperature and relative air humidity (RH). To investigate the effects of temperature and RH during day and night on leaf growth, one variety (IR64) was grown in a growth chamber using 9 day/night regimes around the same mean temperature and RH, which were combinations of 3 temperature treatments (30/20 °C, 25/25 °C, 20/30 °C day/night temperature) and 3 RH treatments (40/90%, 65/65%, 90/40% day/night RH). Day/night leaf elongation rates (LER) were measured and compared to leaf gas exchange measurements and leaf area expansion on the plant level. While daytime LER was mainly temperature-dependent, nighttime LER was equally affected by temperature and RH and closely correlated with leaf area expansion at the plant level. We hypothesize that the same parameters increasing LER during the night also enhance leaf area expansion via shifts in partitioning to larger and thinner leaves. Further, base temperatures estimated from LERs varied with RH, emphasizing the need to take RH into consideration when modeling crop growth in response to temperature.

Localization and Chemical Speciation of Pb in Roots of Signal Grass (Brachiaria decumbens) and Rhodes Grass (Chloris gayana)

2008 ◽  
Vol 42 (12) ◽  
pp. 4595-4599 ◽  
Author(s):  
Peter M. Kopittke ◽  
Colin J. Asher ◽  
F. Pax C. Blamey ◽  
Graeme J. Auchterlonie ◽  
Yanan N. Guo ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Brachiaria Decumbens ◽  
Rhodes Grass ◽  
Chloris Gayana ◽  
Signal Grass

scholarly journals A novel gene LbHLH from the halophyte Limonium bicolor enhances salt tolerance via reducing root hair development and enhancing osmotic resistance

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xi Wang ◽  
Yingli Zhou ◽  
Yanyu Xu ◽  
Baoshan Wang ◽  
Fang Yuan
Keyword(s):  
Salt Tolerance ◽  
Root Hair ◽  
Salt Gland ◽  
Nacl Stress ◽  
35S Promoter ◽  
Osmotic Resistance ◽  
Salt Glands ◽  
Limonium Bicolor ◽  
Root Hair Development ◽  
Hair Development

Abstract Background Identifying genes involved in salt tolerance in the recretohalophyte Limonium bicolor could facilitate the breeding of crops with enhanced salt tolerance. Here we cloned the previously uncharacterized gene LbHLH and explored its role in salt tolerance. Results The 2,067-bp open reading frame of LbHLH encodes a 688-amino-acid protein with a typical helix-loop-helix (HLH) domain. In situ hybridization showed that LbHLH is expressed in salt glands of L. bicolor. LbHLH localizes to the nucleus, and LbHLH is highly expressed during salt gland development and in response to NaCl treatment. To further explore its function, we heterologously expressed LbHLH in Arabidopsis thaliana under the 35S promoter. The overexpression lines showed significantly increased trichome number and reduced root hair number. LbHLH might interact with GLABRA1 to influence trichome and root hair development, as revealed by yeast two-hybrid analysis. The transgenic lines showed higher germination percentages and longer roots than the wild type under NaCl treatment. Analysis of seedlings grown on medium containing sorbitol with the same osmotic pressure as 100 mM NaCl demonstrated that overexpressing LbHLH enhanced osmotic resistance. Conclusion These results indicate that LbHLH enhances salt tolerance by reducing root hair development and enhancing osmotic resistance under NaCl stress.

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