Tolerance and Physiological Responses in Two Populations of Harmel Plant to Silver Stress, A Suitable Candidate for Accumulation of Ag

Author(s):  
Kobra Mahdavian

Abstract By studying harmel plants in Ag metal-contaminated mineral areas, it was found that harmel plants can accumulate Ag metal, so the present study aimed to investigate the effects of Ag exposure (0, 1, 2.5, 5, 10 mgL− 1 Ag) to harmel seedlings. Two populations (metallicolous and non-metallicolous) were compared about Ag tolerance, Ag accumulation, translocation factor (TF), photosynthetic pigments, antioxidant enzyme activity and, non-enzyme metabolite. At first, harmel plants were studied for their ability to accumulate silver metal in a silver metal-contaminated mineral area. Also, the results of hydroponic culture showed that the increase of Ag concentrations in the nutrient solution reduced root length, shoot length, root dry weight, shoot dry weight, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and, total soluble sugars in both populations, but the accumulation is more pronounced in metallicolous populations than non-metallicolous. In response to this, the antioxidant activities were increased under Ag exposure, and sharp in the metallicolous population. In conclusion, the above results show that harmel seems a suitable candidate for Ag-accumulation; and these findings support the use of harmel as an acceptable species for cultivation in soils that are contaminated with Ag and strategies to minimize the toxicity of Ag in plants.

1994 ◽  
Vol 74 (4) ◽  
pp. 693-697 ◽  
Author(s):  
J. T. O'Donovan ◽  
G. M. Jeffers ◽  
M. P. Sharma ◽  
D. Maurice

A chickweed population (R) from a farm near Stony Plain, Alberta, was more resistant to chlorsulfuron than a population (S) collected near Vegreville, Alberta. In greenhouse experiments, the S population was controlled completely by chlorsulfuron applied at 5 g ha−1, whereas 22 g ha−1 was required to reduce dry weight of the R population by 50%. Experiments conducted in a germinator indicated that percentage germination of the R population was higher than that of the S population up to ~ 60 h. Growth analyses in the greenhouse indicated that leaf number, leaf area, shoot dry weight, days to flowering, flower number, seed weight and relative yields differed little between the two populations. In field experiments, control of the R population was poor with the sulfonylurea herbicides, chlorsulfuron, metsulfuron methyl, triasulfuron, amidosulfuron and thifensulfuron. Good to excellent control was obtained with cyanazine/MCPA, linuron, metribuzin, mecoprop, bentazon, metribuzin + MCPA, linuron + MCPA, and mecoprop + bentazon. Key words: Sulfonylurea herbicides, chlorsulfuron, herbicide resistance, relative competitiveness


1997 ◽  
Vol 77 (2) ◽  
pp. 201-205 ◽  
Author(s):  
D. L. Pazdernik ◽  
P. H. Graham ◽  
J. H. Orf

We have previously identified differences among soybean [Glycine max (L.) Merr.] lines in early nodulation and N2 fixation, and related early nodule development and overall plant performance under N-limited field conditions. The objectives of the present study were: 1) to estimate heritabilities for nodule fresh weight (NFW), shoot dry weight (SDW), and root dry weight (RDW) determined 17 d after inoculation (DAI); 2) to examine genetic variation for total nodule soluble protein (TSOLP) at 17 DAI, and SDW and shoot N derived from fixation (SNdfa) at the R5 growth stage; and 3) to assess relationships between early nodulation and subsequent R5 shoot mass and SNdfa. The two populations used were derived from the Minnesota-adapted cultivars Kasota and Parker, and two plant introductions PI 437966 and PI 384469B. Genetic variances within populations were significant for most traits measured at 17 DAI, and at the R5 growth stage. Heritability estimates ranged from 0.79–0.82 for NFW, 0.51–0.56 for SDW, and 0.38–0.40 for RDW, with SDW also correlated with seed size at 17 DAI (r = 0.88**). Additional correlation analyses showed SNdfa correlated with NFW (r = 0.33**) and TSOLP (r = 0.46**). The results of this study suggest that gains from selection are possible for NFW and SDW at early stages of plant development. Key words: Glycine max (L.) Merr., nodulation, nitrogen fixation, heritabilitynot available


Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 588
Author(s):  
Hira Yaqoob ◽  
Nudrat A. Akram ◽  
Samrah Iftikhar ◽  
Muhammad Ashraf ◽  
Noman Khalid ◽  
...  

In the current study, the effects of exogenously applied proline (25 and 50 mM) and low-temperature treatment were examined on the physiochemical parameters in the plants of two cultivars (V1 and V2) of quinoa (Chenopodium quinoa Willd.). The seeds were also exposed to chilling stress at 4 °C before sowing. Plants raised from the seeds treated with low temperature showed reduced plant growth and contents of chlorophyll and carotenoids, but they had significantly increased contents of malondialdehyde, proline, ascorbic acid, total free amino acids, total soluble sugars, and total phenolics, as well as the activity of the peroxidase (POD) enzyme. Cold stress applied to seeds remained almost ineffective in terms of bringing about changes in plant root, hydrogen peroxide, glycine betaine and activities of superoxide dismutase (SOD), and catalase (CAT) enzymes. The exogenous application of proline significantly increased plant growth, the contents of chlorophyll, carotenoids, proline, ascorbic acid, total free amino acids, phenolics, and total soluble sugars, as well as the activities of SOD, POD, and CAT, but it decreased malondialdehyde content. Overall, foliar application of proline was better than the seed treatment in improving root dry weight, root length, chlorophyll a, carotenoids, glycine betaine, ascorbic acid and superoxide dismutase activity, whereas seed pre-treatment with proline was effective in improving shoot dry weight, shoot length, hydrogen peroxide, malondialdehyde, and peroxidase activity in both quinoa cultivars.


Author(s):  
Shilpee Dhali ◽  
, Madhusmit, Pradhan ◽  
Ranjan Kumar Sahoo ◽  
Chinmay Pradhan ◽  
Santanu Mohanty

The discharge of contaminated mining and industrial residues has become a major cause of environmental pollution. Seed is highly protective against external metal stresses. But they are highly sensitive during vegetative developmental process. In this study, germination was conducted in Macrotyloma uniflorum var. Madhu, in order to find out the effect of chromium toxicity on germination, growth and biochemical variations. The seeds were germinated in five different concentrations of chromium (25ìM, 50ìM, 100ìM, 150ìM and 200 ìM) solution. The hydroponically grown plants revealed the toxic phenotypic expression (root length, shoot length, seedling length, shoot vigor index, shoot fresh weight, shoot dry weight, root fresh weight and root dry weight) of plant after 3 growth stage (15 d, 30 d and 45 d). Similarly biochemical characteristics as well as antioxidant activities (Chlorophyll, carotenoid, carbohydrate, reducing sugar, catalase, proline content and peroxidase) were studied to see the toxic effect of chromium.


2003 ◽  
Vol 15 (4) ◽  
pp. 483-491 ◽  
Author(s):  
ALEJANDRA ZÚÑIGA-FEEST ◽  
PATRICIA INOSTROZA ◽  
MARIO VEGA ◽  
LEÓN A. BRAVO ◽  
LUIS J. CORCUERA

Deschampsia antarctica is a freezing-tolerant plant and the only native Poaceae that grows in the Maritime Antarctic. During the long days of the growing season this plant accumulates sucrose (Suc) in the leaves to 36% of the dry weight. The mechanism that leads to this high accumulation is unknown. The effect of day length and low temperature on sucrose phosphate synthase (SPS) (EC: 2.4.1.14) activity and sugar accumulation was studied in D. antarctica and compared with other Poaceae. Three different day lengths: short (SD) (8/16 h), medium (MD) (16/8 h) and long (LD) (21/3 h); and two temperatures: 4°C (cold-acclimated) and 15°C (non-acclimated) were tested. The highest contents in total soluble sugars (TSS) and Suc were reached in crowns and leaves, respectively, in cold-acclimated plants under LD. TSS and Suc contents and SPS activity with cold acclimation were higher in D. antarctica than in other agricultural (wheat, oat and barley) and non-agricultural (D. caespitosa and D. beringensis) Poaceae species. Suc/TSS ratio was higher in all Deschampsia species than in agricultural Poaceae species. SPS activity and sucrose content in leaves were positively correlated only in LD cold acclimated plants. This result shows that SPS activity is responsive to day length in D. antarctica.


2018 ◽  
Vol 6 (3) ◽  
pp. 300-319 ◽  
Author(s):  
Amel A. Tammam ◽  
Samir M. Khalil ◽  
Elsayed E. Hafez ◽  
Atyat M. Elnagar

The objective of the current study was to find out the effect of aluminum on the seedlings pre-treated by two levels of boron concentrations 4μM or 32μM grown in hydroponic solution of Al from 100-500μMAl for 3 days. Data revealed that Al had a negative effect on fresh, dry weight, water content, carbohydrate, protein and amino acids including proline constituents and changes in protein profile were analyzed of fourteen day-old Al-tolerant (‘Sakha 93’) cultivar of Triticum aestivum. The effect of boron treatment was pronounced at 32μM B level. Pretreatment of 4µM B and exposure to 500 µM Al revealed that insoluble protein increased soluble, total protein and total soluble sugars decreased in comparison to Al treatment only. Levels of amino acids most notably proline, the glutathione forming amino acids cysteine, glycine and glutamic and the branched chain amino acids (BCAAs) leucine, isoleucine and valine were increased under Al stress. The obtained results showed the high resistance of ‘Sakha 93’ cultivar to aluminum stress. Aluminum detoxification coincides with increased TSS, TP, Pro, BCAAs contents and polypeptides in the root to cope with alleviation of Al-stress; boron may have a role in this concern.


2016 ◽  
Vol 73 (1) ◽  
pp. 79-86
Author(s):  
Batool Mahdavi

Abstract In this study, the effect of different alkaline concentrations (0, 10, 20, 30, 40, 50, 60 mM) on germination and biochemical characteristics of the two sesame (Sesamum indicum L.) cultivares (Dashtestan and GL-13) which are registered cultivars of Iran were investigated. The experiment was carried out in a completely randomized design with three replications. Results showed that, germination percentage, germination rate, shoot length and dry weight, root length and dry weight and K+ content decreased, whereas, malondialdehyde (MDA), proline, total soluble sugars and Na+ contents increased with increasing alkalinity stress. GL-13 cultivar had the least root and shoot length, proline and K+ content than Dashtestan.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 685a-685
Author(s):  
X. Liu ◽  
P. Robinson ◽  
M.L. Arpaia ◽  
G.W. Witney

Monthly samples were taken from 9-year-old `Hass' avocado trees on Duke 7 rootstock grown at the UC Southcoast Research and Extension Center in Irvine, Calif. Changes in starch and total soluble sugars were monitored from fine and coarse roots, trunk (above the bud union), small diameter stems, leaves, and fruit. When possible, seasonal carbohydrate changes were compared to root and shoot flushing patterns. In all of the vegetative plant organs monitored, total soluble sugars accounted for most of the carbohydrate. Starch accounted for ≈10% of the sample dry weight, whereas the total soluble sugars accounted for ≈18%. D-mannoheptulose and perseitol, both C7 sugars, were the predominant soluble sugars throughout the year. Fructose, glucose, and sucrose accounted for <5% of the total soluble sugars. During fruit development, soluble sugar content of the exo- and mesocarp tissues >25% of the dry weight. The significance of these findings will be discussed in relationship to tree phenology and carbohydrate partitioning.


Author(s):  
Omid Sadeghipour

A pot experiment was conducted to investigate the role of methyl jasmonate (MeJA) in alleviation of the adverse effects of salinity on cowpea. Seeds were soaked in 0, 25 and 50 µM MeJA for 20 h and then the seedlings were irrigated with different concentrations of NaCl (0, 50 and 100 mM). Salt stress markedly decreased growth attributes namely shoot length, shoot and root dry weight and leaf area. NaCl stress also significantly reduced chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins and relative water content (RWC). Furthermore, salinity noticeably increased proline and total soluble sugars content. Nonetheless, seeds treatment with MeJA especially 50 µM, improved the growth of cowpea plants by increasing chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins, proline accumulation, total soluble sugars and RWC under salt stress conditions. Thus results indicate that pretreatment of seeds with MeJA could be used as an effective technique for improving cowpea plants tolerance to salt stress.


2018 ◽  
Vol 26 (2) ◽  
pp. 37-45
Author(s):  
Jelili T. Opabode ◽  
Simbiat Owojori

AbstractThe influence of foliar application of benzylaminopurine (BAP) and gibberellic acid (GA3) alone and in combination on quantitative and qualitative yields of Solanum macrocarpon L. ‘Igbagba’ was investigated to increase the production of the vegetable. Treatments were arranged in randomized complete block design with three replicates. Analysis of variance showed that treatments had significant (p < 0.05) influence on all parameters measured. Foliar application of 20–40 mg·dm−3 of GA3 alone doubled the shoot heights compared with other treatments. The highest leaf area, fresh shoot weight, dry weight and number of regrowth was observed on plants to which foliar application of 40 mg·dm−3 of BAP and 30 mg·dm−3 of GA3 was applied. Combinations of 40 mg·dm−3 of BAP and 30–40 mg·dm−3 of GA3 produced the highest quantities of chlorophyll a and chlorophyll b, carotenoids, total phenolics, soluble sugars and soluble protein. Highest moisture, crude protein, crude fat and ash contents were detected when 40 mg·dm−3 of BAP and 10–40 mg·dm−3 of GA3 were applied. However, the application of GA3 alone promoted crude fiber and carbohydrate synthesis. Leaf Na, P, Ca, Mg, Zn and Fe had highest quantities when 40 mg·dm−3 of BAP was combined with 30–40 mg·dm−3 of GA3. Leaf K was promoted by the application of BAP alone and combination of 40 mg·dm−3 of BAP and 10–20 mg·dm−3 of GA3. The highest number of re-growth was observed when 40 mg·dm−3 of BAP was combined with 30 mg·dm−3 of GA3. Foliar application of 40 mg·dm−3 of BAP and 30 mg·dm−3 of GA3 in combination was suggested for the enhancement of quantitative and qualitative yields of the vegetable.


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