Increased drought resistance of black locust seedlings via pretreatment of seeds with paclobutrazol

1993 ◽  
Vol 23 (12) ◽  
pp. 2548-2551 ◽  
Author(s):  
Shen Hui-Juan ◽  
Zeng Bin
Keyword(s):  
Osmotic Stress ◽  
Water Content ◽  
Drought Resistance ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Black Locust ◽  
Cellular Stress ◽  
Relative Water

The drought resistance of black locust (Robiniapseudoacacia L.) seedlings was increased by pretreatment of seeds with 250 ppm paclobutrazol. Treated seeds produced seedlings with thick roots and higher root/shoot ratios. During osmotic stress, treated plants displayed greater relative water content, lower electrolyte leakage, and fewer symptoms of wilt when compared with untreated black locust seedlings. Paclobutrazol-treated seedlings accumulated more proline than untreated seedlings in response to drought. However, osmotically induced accumulation of putrescine, a possible marker of cellular stress, was reduced in the treated plants.

Studies on the Status of Unburnt Eucalyptus Woodland at Ocean Grove, Victoria. V. The Interactive Effects of Droughting and Shading on Seedlings Under Competition.

1979 ◽  
Vol 27 (3) ◽  
pp. 285 ◽  
Author(s):  
JR Withers
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Drought Resistance ◽  
Relative Water Content ◽  
Height Growth ◽  
Interactive Effects ◽  
Wide Range ◽  
Relative Water ◽  
Pre Treatment ◽  
Grass Sward

Casuarina littoralis seedlings are inherently more drought-resistant than Eucalyptus ovata seedlings over a wide range of environmental conditions. Moderate shade pre-treatment (30% of full daylight) decreased the drought resistance of seedlings of E. ovata, Acacia pycnantha and C. stricta but not that of C. littoralis seedlings. Deep shade pre-treatment (8 % of full daylight) decreased the drought resistance of all species and was associated with decreased rootlshoot ratios. Both shaded and non-shaded C. littoralis seedlings closed stomata at higher relative water contents (about 80% and 88 % respectively) than did E. ovata seedlings (about 36 % and 63 % respectively). Shading decreased the relative water content at which E. ovata closed stomata and reduced the relative decrease in water potential which occurred with unit decreases in relative water content. When E. ovata and C. littoralis seedlings were grown in competition, the larger E. ovata dominated the drought response of plants under both high and low light conditions. E. ovata rapidly depleted moisture supplies thereby subjecting C. littoralis to greater stress and earlier death than it experienced in monoculture. C. littoralis seedlings grown and droughted in competition with E. ovata exhibited smaIIer decreases in water potential per unit decrease in relative water content than seedlings grown in monoculture. The height growth of E. ovata grown in monoculture and in competition with C. littoralis was reduced for at least 10-15 weeks after the wilting treatment, but height growth of C. littoralis was not affected. Eucalypts wilted at higher water potentials (-4.3 MPa) than did C. littoralis seedlings (- 6.3 MPa). It is suggested that the replacement of E. ovata by C. littoralis at Ocean Grove, Vic. may be partly due to the differential effects of shading on the drought resistance of seedlings which become established in the grass sward of canopy gaps.

scholarly journals Biochemical metabolism of two cultivars of cowpea treated with 24-Epibrassinolide and subjected to saline stress

2019 ◽  
Vol 13 ((03) 2019) ◽  
pp. 444-451
Author(s):  
Kerolém Prícila Sousa Cardoso ◽  
Susana Silva Conceição ◽  
Ana Ecídia de Araújo Brito ◽  
Jéssica Taynara da Silva Martins ◽  
Liliane Corrêa Machado ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nitrate Reductase ◽  
Water Content ◽  
Glycine Betaine ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Reductase Activity ◽  
Soluble Proteins ◽  
Saline Stress ◽  
Relative Water

We aimed to evaluate the changes in biochemical metabolism generated by salt stress and to investigate the effect of brassinosteroids in mitigating of this stress on two cultivars of Vigna unguiculata L. We used a completely randomized experimental design in a 2 x 3 x 3 factorial scheme, using two cultivars of cowpea (BRS Guariba and BR3 Tracuateua - moderately tolerant and sensitive to salinity, respectively), three concentrations of brassinosteroids (0, 0.2 and 0.4 μM Br) and three concentrations of NaCl (0 , 50 and 100 mM NaCl), with four replicates. The following evaluations were carried out: relative water content, electrolyte leakage, nitrate levels, nitrate reductase activity, free ammonium, total soluble amino acids, soluble proteins, glycine betaine and proline. The results showed that salinity at 100 mM affected the nitrate reductase enzyme activity, the relative water content, total soluble amino acids and soluble proteins for cultivars BR3 Tracuateua, and BRS Guariba, but the 24-epibrassinolid attenuated the effects of salinity for these variables. The concentration of 0.2 μM of Br increased 55% and 20% in proline and glycine betaine contents, respectively, in both of cultivars. The plants under stress saline and 0.2 mM of 24-epibrassinolid, presented 42% and 58% reductions in electrolyte leakage of BR3 Tracuateua and BRS Guariba cultivars, respectively. The concentrations of ammonium were slightly varied. Therefore, the application of 0.2 μM of 24-epibrassinolid caused a greater acclimatization of the cultivars, being the BR3 Tracuateua (sensitive to salt) cultivar more expressive in most treatments.

scholarly journals Effect of Salt-Tolerant Bacterial Inoculations on Rice Seedlings Differing in Salt-Tolerance under Saline Soil Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1030 ◽  
Author(s):  
Rakiba Shultana ◽  
Ali Tan Kee Zuan ◽  
Mohd Rafii Yusop ◽  
Halimi Mohd Saud ◽  
Arolu Fatai Ayanda
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Water Content ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Rice Variety ◽  
Salt Tolerant ◽  
Relative Water ◽  
Plant Growth Promoting ◽  
Growth Promoting

Salt-tolerant plant growth-promoting rhizobacteria (PGPR) could be an alternative to alleviate salinity problems in rice plants grown in the coastal areas. This study was conducted to isolate and characterize salt-tolerant PGPR and observe their effects on the physiological and biochemical properties of rice plants grown under non-saline and saline glasshouse conditions. Three strains were selected based on their salt-tolerance and plant growth-promoting properties under in vitro saline conditions. These strains were identified as Bacillus tequilensis (UPMRB9), Bacillus aryabhattai (UPMRE6), and Providencia stuartii (UPMRG1) using a 16S rRNA technique. The selected strains were inoculated to three different rice varieties, namely BRRI dhan67 (salt-tolerant), Putra-1 (moderate salt-tolerant), and MR297 (salt-susceptible) under glasshouse conditions. Results showed that the MR297 rice variety inoculated with UPMRB9 produced the highest total chlorophyll content, with an increment of 28%, and lowest electrolyte leakage of 92%. The Putra-1 rice variety also showed a 156% total dry matter increase with the inoculation of this bacterial strain. The highest increase of relative water content and reduction of Na/K ratio were found upon inoculation of UPMRE6 and UPMRB9, respectively. The biggest significant effects of these bacterial inoculations were on relative water content, electrolyte leakage, and the Na/K ratio of the BRRI dhan67 rice variety under saline conditions, suggesting a synergistic effect on the mechanisms of plant salt-tolerance. This study has shown that the application of locally-isolated salt-tolerant PGPR strains could be an effective long-term and sustainable solution for rice cultivation in the coastal areas, which are affected by global climate change.

scholarly journals Etanol e ácido cítrico aumentam a longevidade de gérberas cv. Mistique

2019 ◽  
Vol 25 (2) ◽  
pp. 109-118
Author(s):  
Rúbia Kécia Marins Maia ◽  
Edivan Amaro da Silva ◽  
Rafael Mateus Alves ◽  
Maria Aparecida Dos Santos Morais ◽  
Marcos Ribeiro da Silva Vieira ◽  
...  
Keyword(s):  
Citric Acid ◽  
Water Content ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Distilled Water ◽  
Cut Flowers ◽  
Water Control ◽  
Relative Water ◽  
Stem Bending ◽  
Application Methods

Ethanol and citric acid can increase longevity in some cut flowers. However, its use must be extremely careful, with application methods and specific concentrations for each type of cut flower. Thus, the objective was to examine the physico-chemical and physiological changes in Gerbera cv. Mistique cut flowers treated with ethanol (Et) and/or citric acid (CA). Stem were selected and standardized to a length of 35 cm and maintained at 20 ± 2 ºC and RH 65 ± 2%, under continuous lighting. The flowers were subjected to two application methods (pulsing for 48 h and maintenance), using different concentrations of Et (4%, 6%, and 8%) and/or CA (100 and 200 mg L-1) and distilled water (control). A visual assessment and analyses of longevity, stem bending, fresh mass, relative water content, electrolyte leakage, and peroxidase and polyphenol oxidase enzyme activities were performed at every two days. The Et (4%) + CA (100 mg L-1) solution provided the greatest longevity, regardless of the application method. These results were the basis for a third experiment, in which the stems were immersed in pulsing solutions of Et (4%) and/or CA (100 mg L-1) and distilled water (control). The Gerbera flowers under Et + CA solution showed lower fresh mass loss and electrolyte leakage, higher relative water content and a slower increase in polyphenol oxidase and peroxidase activities. This allowed for delayed stem bending and better appearance, resulting in greater longevity compared to the other solutions.

scholarly journals Beneficial Effects of Biochar and Chitosan on Antioxidative Capacity, Osmolytes Accumulation, and Anatomical Characters of Water-Stressed Barley Plants

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 630 ◽  
Author(s):  
Yaser Hafez ◽  
Kotb Attia ◽  
Salman Alamery ◽  
Abdelhalim Ghazy ◽  
Abdullah Al-Doss ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Drought Stress ◽  
Water Content ◽  
Plant Height ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Relative Water ◽  
Number Of Leaves ◽  
The Impact ◽  
Chlorophyll Concentrations

The impact of biochar and chitosan on barley plants under drought stress conditions was investigated during two field experiments. Our results confirmed that drought stress negatively affected morphological and physiological growth traits of barley plants such as plant height, number of leaves, chlorophyll concentrations, and relative water content. However, electrolyte leakage (EL%), lipid peroxidation (MDA), soluble sugars, sucrose and starch contents significantly increased as a response to drought stress. Additionally, 1000 grain weight, grains yield ha−1 and biological yield significantly decreased in stressed barley plants, also anatomical traits such as upper epidermis, lower epidermis, lamina, and mesophyll tissue thickness as well as vascular bundle diameter of flag leaves significantly decreased compared with control. The use of biochar and chitosan led to significant increases in plant height, number of leaves, and chlorophyll concentrations as well as relative water content; nevertheless these treatments led to significant decreases in electrolyte leakage (EL%) and lipid peroxidation (MDA) in the stressed plants. Moreover, anatomical and yield characters of stressed barley plants were improved with application of biochar and chitosan. The results proved the significance of biochar and chitosan in alleviating the damaging impacts of drought on barley plants.

Ameliorative role of Silicon on Osmoprotectants, Antioxidant Enzymes and Growth of Maize Grown Under Alkaline Stress

2021 ◽  
Author(s):  
Sriramachandrasekharan Malayappa venkataraman ◽  
Gokula Priya Natarajan ◽  
Manivannan Rengarajan ◽  
Prakash Muthu Arjuna Samy
Keyword(s):  
Antioxidant Enzymes ◽  
Water Content ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Dry Weight ◽  
Water Soluble ◽  
Maximum Effect ◽  
Antioxidant Systems ◽  
Alkaline Stress ◽  
Relative Water

Abstract Purpose Maize is grown under a wide spectrum of soil and climatic conditions. Maize is moderately sensitive to salt stress and response of maize under alkaline stress is scanty. Further, silicon is known to protect crops from abiotic stress. Hence, a pot experiment was conducted to study the mechanism on the effect of silicon on maize grown in alkaline stress Methods Maize CO 8 was grown in soil treated with four levels of alkaline stress (0, 25, 50, 75 mM) created through addition of sodium carbonate and three levels of silicon (0,100 and 150 kg ha− 1) applied to root through sodium meta silicate. The experiment was conducted in factorial CRD with three replications. Results Alkaline stress at graded levels caused reduction in growth (5 to 16%), dry weight (28 to 59%) and relative water content (5 to 23%). But electrolyte leakage (6 to 49%), proline (26 to 62%), phenol (8 to 44%), protein (6 to 19%), anti-oxidant systems viz., peroxidase (30 to 52%), SOD (4 to 16%) and catalase activities (32 to 127%) increased with increase in alkaline stress level. Soil application of silicon at different levels improved growth ( 5 to 10%) and dry weight (17 to 30%) of maize, relative water content (6 to 12%) and antioxidant enzymes ( 25 to 52%), water soluble protein ( 7 to10%), phenol ( 10 to 18%) while reduced electrolyte leakage( 15 to 25%) and proline( 17 to 29%). Conclusions It is evident from the study that root supplementation of silicon improved the growth and dry weight of maize crop grown in alkaline stress soil through its action on antioxidant systems and maximum effect was evident with 150 kg Si/ha

Physiological and anatomical responses of wheat to induced dehydration and rehydration

2013 ◽  
Vol 8 (5) ◽  
pp. 499-503
Author(s):  
Konstantina Kocheva ◽  
Peter Petrov ◽  
Georgi Georgiev
Keyword(s):  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Osmotic Stress ◽  
Water Content ◽  
Relative Water Content ◽  
Water Status ◽  
Free Proline ◽  
Leaf Water Status ◽  
Wheat Seedlings ◽  
Relative Water

AbstractHydroponically grown wheat seedlings of two prominent Bulgarian cultivars (Katya and Prelom) were subjected to 48 h osmotic stress with PEG 8000 and were then rehydrated. The degree of stress was evaluated by monitoring relative water content, lipid peroxidation level, and accumulation of free proline and hydrogen peroxide in the leaves. Anatomy and ultrastructure of leaf tissue were observed under light microscopy. After imposition of stress, drought tolerant cultivar Katya displayed higher free proline content and significantly lower malondialdehyde and peroxide concentration in leaves than in the leaves of susceptible cultivar Prelom. After 24 h of rehydration Katya showed better ability to restore leaf water status and an apparent tendency towards recovery, whereas Prelom sustained higher levels of hydrogen peroxide, lipid peroxidation products and free proline and markedly low relative water content. Here, we have uncovered some of the characteristics displayed by cultivar Katya that enable it to survive and recover from severe osmotic stress. Interestingly, there was congruence between our results and the high level of cultivar Katya drought tolerance observed in the field.

scholarly journals The change in the biometric and physiological parameters of aster (Callistephus chinensis), helichrysum (Helichrysum bracteatum) and echinacea (Echinaceae purpurea) under conditions of induced water deficit

2021 ◽  
Vol 13 (30) ◽  
pp. 6-12
Author(s):  
Valeria Ivanova ◽  
◽  
Nadejda Zapryanova ◽  
Keyword(s):  
Water Content ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Climate Models ◽  
Global Climate ◽  
Ornamental Plants ◽  
Field Capacity ◽  
Global Climate Models ◽  
Relative Water ◽  
Helichrysum Bracteatum

The global climate models predict changed precipitation patterns with frequent episodes of drought. Scarcity of water is a severe environmental constraint to plant productivity. Plants display a variety of physiological and biochemical responses at cellular and whole-organism levels towards prevailing drought stress. This study included container experiments with three flower crops aster (Callistephus chinensis), helichrysum (Helichrysum bracteatum) and echinacea (Echinaceae purpurea). Drought was simulated by reducing the number of watering’s to field capacity from 25–30 to 85–90 %. Three levels of watering were studied - three times, twice and once a week. The results showed that the cultivation of ornamental plants in containers under reduced watering conditions (twice or once a week) for a period of 3 months led to considerable inhibition of growth and even to plants death. The relative water content and the level of electrolyte leakage vary depending on the weekly number of waterings. The highest values of electrolyte leakage were reported in a single watering for aster -5107.1µS / g, for helichrysum -8314.9 µS / g and for echinacea -3722.8 µS / g. The high rates of conductivity, especially with one-time weekly watering, are evidence of the damage caused by the simulated water stress. This corresponds to the reported low percentages of RWC % and the low values for the height and diameter of the plants. The relative water content in plant tissues decreases depending on the irrigation regime. The lowest values for aster, helichrysum and echinacea were again observed in the variant with a single weekly watering, respectively 15%, 11.5% and 15.8%.

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