Physiological, anatomical and antioxidant responses to salinity in the Mediterranean pastoral grass plant Stipa lagascae

2017 ◽  
Vol 68 (9) ◽  
pp. 872 ◽  
Author(s):  
Raoudha Abdellaoui ◽  
Fayçal Boughalleb ◽  
Zohra Chebil ◽  
Maher Mahmoudi ◽  
Azaiez Ouled Belgacem

Soil and water salinity is a major environmental problem in the dry Mediterranean regions, affecting rangeland production. This study investigated the effects of salinity on the wild perennial grass (Poaceae) species Stipa lagascae R. & Sch., a potential forage plant that could be used to rehabilitate degraded rangelands in dry areas. In a laboratory, 3-month-old S. lagascae seedlings were subjected to increasing salt treatments (0–400 mm NaCl) for 45 days. Physiological and biochemical parameters such as leaf water potential (Ψw), leaf relative water content (RWC), proline, total soluble sugars, Na+, K+ and Ca2+ contents, and catalase, ascorbate peroxidase and glutathione reductase activities were measured. Total soluble sugars and proline concentrations increased and Ψw and RWC decreased with increasing salt concentrations. Lower salt concentrations induced a non-significant degradation of chlorophyll pigments. Shoot Na+ content increased with a salinity level, whereas shoot K+ and Ca2+ concentrations decreased and the K+ : Na+ ratio was lower. The salinity threshold, above which S. lagascae showed signs of damage, occurred at 300 mm. Plants have evolved reactive oxygen species (ROS) scavenging enzymes including catalase, ascorbate peroxidase and glutathione reductase, which provide cells with an efficient mechanism to neutralise ROS. The tolerance strategies of S. lagascae to moderate salinity seem to include osmotic adjustment through total soluble sugars and proline accumulation, and highly inducible antioxidative defence. Further investigations are necessary to study the effect of salt stress on distribution of ions (Na+, K+, Ca2+, Mg2+, Cl–, NO3–, SO42–) and osmotic adjustment. Photosynthesis and water-use efficiency parameters could be also useful tools.

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 436
Author(s):  
Peichen Hou ◽  
Feifei Wang ◽  
Bin Luo ◽  
Aixue Li ◽  
Cheng Wang ◽  
...  

Drought stress is a major environmental constraint for plant growth. Climate-change-driven increases in ambient temperatures resulted in reduced or unevenly distributed rainfalls, leading to increased soil drought. Carex duriuscula C. A. Mey is a typical drought-tolerant sedge, but few reports have examined the mechanisms conferring its tolerant traits. In the present study, the drought responses of C. duriuscula were assessed by quantifying activity of antioxidant enzymes in its leaf and root tissues and evaluating the relative contribution of organic and inorganic osmolyte in plant osmotic adjustment, linking it with the patterns of the ion acquisition by roots. Two levels of stress—mild (MD) and severe (SD) drought treatments—were used, followed by re-watering. Drought stress caused reduction in a relative water content and chlorophyll content of leaves; this was accompanied by an increase in the hydrogen peroxide (H2O2) and superoxide (O2−) contents in leaves and roots. Under MD stress, the activities of catalase (CAT), peroxidase (POD), and glutathione peroxidase (GPX) increased in leaves, whereas, in roots, only CAT and POD activities increased. SD stress led to an increase in the activities of CAT, POD, superoxide dismutase (SOD), and GPX in both tissues. The levels of proline, soluble sugars, and soluble proteins in the leaves also increased. Under both MD and SD stress conditions, C. duriuscula increased K+, Na+, and Cl− uptake by plant roots, which resulted in an increased K+, Na+, and Cl− concentrations in leaves and roots. This reliance on inorganic osmolytes enables a cost-efficient osmotic adjustment in C. duriuscula. Overall, this study revealed that C. duriuscula was able to survive arid environments due to an efficient operation of its ROS-scavenging systems and osmotic adjustment mechanisms.


Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 74
Author(s):  
Ragab S. Taha ◽  
Mahmoud F. Seleiman ◽  
Bushra Ahmed Alhammad ◽  
Jawaher Alkahtani ◽  
Mona S. Alwahibi ◽  
...  

Salinity is one of the most severe environmental stresses that negatively limits anatomical structure, growth and the physiological and productivity traits of field crops. The productivity of lupine plants is severely restricted by abiotic stress, particularly, salinity in arid and semiarid regions. Activated yeast extract (AYE) can perform a vital role in the tolerance of environmental stress, as it contains phytohormones and amino acids. Thus, field experiments were conducted to explore the potential function of active yeast extract (0, 50, 75, and 100 mL AYE L−1) in mitigating the harmful impacts of salinity stress (EC = 7.65 dS m−1) on anatomical structure, growth, and the physiological and productivity traits of two lupine cultivars: Giza 1 and Giza 2. The different AYE treatments resulted in a substantial improvement in studied attributes, for example the growth, anatomical, physiological characteristics, and seed yields of treated lupine cultivars compared with untreated plants. Among the AYE doses, 75 mL L−1 significantly improved plant growth, leaf photosynthetic pigments, total soluble sugars, total protein, and seed yields, and exposed the best anatomical attributes of the two lupine cultivars grown under saline stress. The exogenous application of 75 mL AYE L−1 was the most influential, and it surpassed the control results by 45.9% for 100-seed weight and 26.9% for seed yield per hectare. On the other hand, at a concentration of 75 mL L−1 AYE there was a decrease in the alkaloids and endogenous proline under the studied salinity stress conditions. Promoted salinity stress tolerance through sufficient AYE dose is a hopeful strategy to enhance the tolerance and improve productivity of lupine into salinity stress. Furthermore, the response of lupine to salinity stress appears to rely on AYE dose. The results proved that Giza 2 was more responsive to AYE than Giza 1, showing a better growth and higher yield, and reflecting further salinity tolerance than the Giza 1 cultivar.


Author(s):  
Muhammad Asaad Bashir ◽  
Xiukang Wang ◽  
Muhammad Naveed ◽  
Adnan Mustafa ◽  
Sobia Ashraf ◽  
...  

Soil pollution with heavy metal is a serious problem across the globe and is on the rise due to the current intensification of chemical industry. The leather industry is one of them, discharging chromium (Cr) in huge quantities during the process of leather tanning and polluting the nearby land and water resources, resulting in deterioration of plant growth. In this study, the effects of biochar application at the rate of 3% were studied on four maize cultivars, namely NK-8441, P-1543, NK-8711, and FH-985, grown in two different tannery polluted Kasur (K) and Sialkot (S) soils. Maize plants were harvested at vegetative growth and results showed that Cr toxicity adversely not only affected their growth, physiology, and biochemistry, but also accumulated in their tissues. However, the level of Cr toxicity, accumulation, and its influence on maize cultivars varied greatly in both soils. In this pot experiment, biochar application played a crucial role in lessening the Cr toxicity level, resulting in significant increase in plant height, biomass (fresh and dry), leaf area, chlorophyll pigments, photosynthesis, and relative water content (RWC) over treatment set as a control. However, applied biochar significantly decreased the electrolyte leakage (EL), antioxidant enzymes, lipid peroxidation, proline content, soluble sugars, and available fraction of Cr in soil as well as Cr (VI and III) concentration in root and shoot tissues of maize plant. In addition to this, maize cultivar differences were also found in relation to their tolerance to Cr toxicity and cultivar P-1543 performed better over other cultivars in both soils. In conclusion, biochar application in tannery polluted soils could be an efficient ecofriendly approach to reduce the Cr toxicity and to promote plant health and growth.


2021 ◽  
Author(s):  
Lynn Doran ◽  
Amanda P. De Souza

Quantification of total soluble sugars (as glucose) in plant tissue extracts via the sulfuric phenol method adapted for 96 well plates.


2018 ◽  
Vol 14 (3) ◽  
pp. 113-121
Author(s):  
Tamara Torres Tanan ◽  
Marilza Neves do Nascimento ◽  
Romeu da Silva Leite

The Physalisbelongs to the Solanaceae family and has sweetish fruit that can be eaten fresh or processed. In Brazil only Physalis peruvianais commercialized, it is necessary research to encourage the cultivation of other promising speciesof the genus. The aim of this study was evaluate the productivity and the physical and biochemical characteristics of P. angulata, P.pubescensand P. ixocarpafruits, in different stages,in Feira de Santana, Bahia. Productivity and the number of fruits in the breeding period were evaluated.In the fruits, longitudinal (LD) and transverse (TD) diameters, the LD/TD ratio,the masses of fruit, the protein content,reducing sugars,and total soluble sugars were analyzed. The results showed differences between species, with higher number of fruits for P. angulata(140,5). P. ixocarpashowed higher productivity (9 t ha-1) and fruit with greater mass and diameter,however P. pubescensand P. angulatashowed round fruits and higher sugar content, desirable characteristics for fresh consumption and for industrialization.


2010 ◽  
Vol 135 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Qi Chai ◽  
Fang Jin ◽  
Emily Merewitz ◽  
Bingru Huang

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.


Author(s):  
Adriana dos S. Ferreira ◽  
Caio C. P. Leal ◽  
Bruno da S. Guirra ◽  
Salvador B. Torres ◽  
Marco Porceddu ◽  
...  

ABSTRACT Saline irrigation water at high levels causes disturbance in the growth of more sensitive plants. The objective of this research was to evaluate the initial growth of Pityrocarpa moniliformis seedlings under different electrical conductivity in irrigation water through physiological and biochemical analyses. The experiment was conducted in a greenhouse with five water electrical conductivities (0.5, 2.0, 4.0, 6.0 and 8.0 dS m-1) and four repetitions of 20 plants each, arranged in a randomized block design. Application of the treatments with irrigation water containing NaCl began at 30 days after sowing. To determine the behaviour of the species, the following variables were analysed: stem diameter, plant height, number of leaves, leaf area, Dickson quality index, shoot dry mass, root dry mass and total dry mass, as well as the biochemical variables, such as the concentrations of total soluble sugars, free proline and chlorophylls a and b. The increase in irrigation water salinity hampered the growth of P. moniliformis seedlings, with electrical conductivity of 0.5 dS m-1 being the limit for maximum production. The results also indicated that the deleterious effects of salt stress on P. moniliformis seedlings variables increase in concentrations of proline, total soluble sugars and betaine glycine.


Sign in / Sign up

Export Citation Format

Share Document