Ecophysiological responses of almond (Prunus dulcis) seedlings to cadmium stress

Biologia ◽  
2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Nada Elloumi ◽  
Mohamed Zouari ◽  
Leila Chaari ◽  
Chiraz Jomni ◽  
Bechir Ben Rouina ◽  
...  

AbstractAlmond (Prunus dulcis L.) seedlings were exposed to 0, 25, 50, 100 and 150 μM of CdCl2 in a solution culture under controlled conditions. The effects of cadmium (Cd) exposure on almond seedlings growth, stomatal architecture, gas exchange and physiological parameters were investigated.Under cadmium stress conditions, significant decrease in fresh and dry weight, length of shoot and chlorophyll content were observed. Stomatal conductance, transpiration and net photosynthetic rates were generally depressed by Cd stress, despite stomatal frequency values and stomatal pore size remained unchanged. Exposure to Cd severely restricted the starch content and increased soluble sugars.

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 182
Author(s):  
Ruchi Bansal ◽  
Swati Priya ◽  
Harsh Kumar Dikshit ◽  
Sherry Rachel Jacob ◽  
Mahesh Rao ◽  
...  

Cadmium (Cd) is a hazardous heavy metal, toxic to our ecosystem even at low concentrations. Cd stress negatively affects plant growth and development by triggering oxidative stress. Limited information is available on the role of iron (Fe) in ameliorating Cd stress tolerance in legumes. This study assessed the effect of Cd stress in two lentil (Lens culinaris Medik.) varieties differing in seed Fe concentration (L4717 (Fe-biofortified) and JL3) under controlled conditions. Six biochemical traits, five growth parameters, and Cd uptake were recorded at the seedling stage (21 days after sowing) in the studied genotypes grown under controlled conditions at two levels (100 μM and 200 μM) of cadmium chloride (CdCl2). The studied traits revealed significant genotype, treatment, and genotype × treatment interactions. Cd-induced oxidative damage led to the accumulation of hydrogen peroxide (H2O2) and malondialdehyde in both genotypes. JL3 accumulated 77.1% more H2O2 and 75% more lipid peroxidation products than L4717 at the high Cd level. Antioxidant enzyme activities increased in response to Cd stress, with significant genotype, treatment, and genotype × treatment interactions (p < 0.01). L4717 had remarkably higher catalase (40.5%), peroxidase (43.9%), superoxide dismutase (31.7%), and glutathione reductase (47.3%) activities than JL3 under high Cd conditions. In addition, L4717 sustained better growth in terms of fresh weight and dry weight than JL3 under stress. JL3 exhibited high Cd uptake (14.87 mg g−1 fresh weight) compared to L4717 (7.32 mg g−1 fresh weight). The study concluded that the Fe-biofortified lentil genotype L4717 exhibited Cd tolerance by inciting an efficient antioxidative response to Cd toxicity. Further studies are required to elucidate the possibility of seed Fe content as a surrogacy trait for Cd tolerance.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 454c-454
Author(s):  
Anil P. Ranwala ◽  
Beth Hardin ◽  
William B. Miller

The energy and carbon needs for early shoot growth in tulips are mainly provided by reserve carbohydrates in bulbs. The cold-treatment of bulbs before greenhouse forcing enhances the breakdown and remobilization of reserve carbohydrates in bulb scales, and is necessary for proper shoot growth and flowering in tulips. Tulip bulbs are known to contain both starch and fructans as reserve carbohydrates. We evaluated several extraction solvents, including ethanol and distilled water, and several extraction temperatures to accurately determine the amounts of different types of non-structural carbohydrates in tulip bulb scales. Extraction with distilled water resulted in excessive solubilization of starch. For example, extraction at 70 °C solubilized more than 80% of starch to glucan polymers. On the other hand, 80% ethanol at 70 °C extracted all soluble sugars including fructans with no apparent solubilization of starch. The changes in non-structural carbohydrates in the outermost bulb scale of tulip (Tulipa gesneriana L. `Frankfurt') during 12 weeks of cooling at 8.8 °C followed by 5 weeks of greenhouse forcing were determined. Starch was the major carbohydrate in bulb scales consisting of ≈70% of the dry weight at the beginning of cold treatment. Starch content per scale decreased slightly during cold treatment, but rapidly after transferring to greenhouse. Sucrose and soluble fructan content per scale increased during cold treatment, then decreased after transferring to greenhouse. Glucose content per scale remained fairly constant during cooling and greenhouse forcing, while fructose content increased in the greenhouse.


2010 ◽  
Vol 2 (4) ◽  
pp. 76-82 ◽  
Author(s):  
Hossam Saad EL-BELTAGI ◽  
Amal A. MOHAMED ◽  
Mohamed M. RASHED

Presented study has demonstrated that exposure of plants to toxic heavy metal Cd results a reduction in plant growth. Varied concentrations of CdCl2, ranging from 0.0 to 50 ppm in the germinating media reduced leaf area of radish plant, chlorophyll and carotenoid contents. Greater loss of chlorophyll b content than chlorophyll a was observed especially under 50 ppm Cd exposure. With regards to the distribution of Cd in roots and leaves, the obtained data showed that the maximum accumulation of Cd occurred in roots followed by leaves. Generally, Fe, Zn, Mn and Cu declined in leaves compared to the roots. Furthermore, substantial increases were observed in antioxidant enzymes, such as catalase (CAT), glutathione S-transferase (GST) and peroxidase (POD), in Cd-stressed plants in comparison with control. The Cd stress also induced several changes in CAT and POD isozyme profiles and enhanced their activities. The results suggest that the reduction of leaf area and pigment content together with antioxidant enzymes and isozyme patterns can be used as indicators to Cd contamination.


2021 ◽  
Vol 23 (1) ◽  
pp. 332
Author(s):  
Jiajie Meng ◽  
Xinming Gao ◽  
Shengyu Luo ◽  
Chenwen Lin ◽  
Chen Du ◽  
...  

Cadmium (Cd) is a heavy metal toxicant and is widely distributed in aquatic environments. It can cause excessive production of reactive oxygen species (ROS) in the organism, which in turn leads to a series of oxidative damages. Thioredoxin (Trx), a highly conserved disulfide reductase, plays an important role in maintaining the intracellular redox homeostasis in eukaryotes and prokaryotes. Phascolosoma esculenta is an edible marine worm, an invertebrate that is extensively found on the mudflats of coastal China. To explore the molecular response of Trx in mudflat organisms under Cd stress, we identified a new Trx isoform (Trx-like protein 1 gene) from P. esculenta for the first time, designated as PeTrxl. Molecular and structural characterization, as well as multiple sequence and phylogenetic tree analysis, demonstrated that PeTrxl belongs to the Trx superfamily. PeTrxl transcripts were found to be ubiquitous in all tissues, and the highest expression level occurred in the coelomic fluid. Exposure to three sublethal concentrations of Cd resulted in the upregulation and then downregulation of PeTrxl expression levels over time in coelomic fluid of P. esculenta. The significant elevation of PeTrxl expression after 12 and 24 h of Cd exposure at 6 and 96 mg/L, respectively, might reflect its important role in the resistance to Cd stress. Recombinant PeTrxl (rPeTrxl) showed prominent dose-dependent insulin-reducing and ABTS free radical-scavenging abilities. After exposure to 96 mg/L Cd for 24 h, the ROS level increased significantly in the coelomic fluid, suggesting that Cd induced oxidative stress in P. esculenta. Furthermore, the injection of rPeTrxl during Cd exposure significantly reduced the ROS in the coelomic fluid. Our data suggest that PeTrxl has significant antioxidant capacity and can protect P. esculenta from Cd-induced oxidative stress.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 648d-648
Author(s):  
Jack W. Buxton ◽  
Donna Switzer ◽  
Guoqiang Hou

Marigold seedlings, 3 weeks old, were grown in natural light growth chambers at 3 day/night temperature regimes, 8°N/16°D, 13°N/20°D and 18°N/24°D, in a factorial combination with ambient and 1000-1500 ppm CO2. Seedlings were harvested at regular intervals during a 24 hr period and were analyzed for soluble sugars (reducing sugars and sucrose) and starch. Neither temperature nor CO2 concentration affected the accumulation of soluble sugars or starch during the day or night. The soluble sugar concentration ranged from 3% of dry weight at sunrise to 6% at mid-day; the concentration changed little during the night. Light intensity was different during replications of the experiment. Increased light intensity appeared to cause a slight increase in the soluble sugars maintained by the seedling during the day. Accumulated starch increased 6% to 8% from sunrise to late afternoon. Preliminary results indicate that light intensity greatly affected the concentration of starch. On the higher light intensity day, starch accumulated to a maximum of 18% of dry weight; whereas on the lower light intensity day the maximum concentration was 10%. During the night following the lower light intensity day, the starch concentration decreased to approximately 3% by the end of the night; following a brighter day the starch content was 13% at the end of the night.


2021 ◽  
Vol 49 (3) ◽  
pp. 11924
Author(s):  
Seyed A. HOSSEINI ◽  
Roya ROSTAMI ◽  
Behrooz ESMAIELPOUR ◽  
Alireza ETMINAN ◽  
Ghobad SALIMI

Thyme (Thymus vulgaris L.) is one of the most important medicinal plants used in various pharmaceutical, osmotic, health, and food industries. Arbuscular mycorrhizal fungi (AMF) symbiosis is viewed as one of the several methods to improve growth under heavy metals stress. To investigate the effects of cadmium (Cd) and AMF bio-fertilizers on the growth and morpho-physiological characteristics of thyme, a greenhouse experiment was performed in three replications. Experimental treatments included Cd at three levels 0, 75, and 150 mg/kg of soil and AMF at three levels without inoculation, inoculation with Funneliformis etunicatum, and Funneliformis mosseae. Cadmium stressed plant showed reduced plant height, number of leaves, stem fresh and dry weight, and root fresh and dry weight while AMF inoculation enhanced the increased means of these traits considerably. Inoculation with F. mosseae also ameliorated the Cd stress (150 mg/kg) induced reduction in plant height, number of leaves, and stem and root dry weight by 13.41%, 8.42%, 30.3%, and 22.2%, respectively. Cadmium stress reduced membrane stability index while AMF inoculation enhanced membrane stability index considerably. An increase in soluble carbohydrate and proline content was observed due to Cd stress and AMF inoculation caused a further increase in these two metabolite contents ensuring better growth under Cd stressed conditions. Results indicated that F. mosseae had a higher efficiency in increasing morphological traits and improving physiological characteristics than F. etunicatum. Overall, AMF inoculation, especially F. mosseae significant ameliorative potential for Cd toxicity in thyme plants.


2021 ◽  
Vol 56 ◽  
pp. 113-127
Author(s):  
M. Zahidul Islam Hawlader TUHIN ◽  
◽  
Taufika Islam ANEE ◽  
Naznin AHMED ◽  
Mira RAHMAN ◽  
...  

An experiment was conducted to investigate the effect of different levels of cadmium (Cd) stress on germination, morphology, physiology and yield of rice. There were five treatments, viz. control (no Cd), 0.5 mM CdCl2, 1 mM CdCl2, 1.5 mM CdCl2 and 2 mM CdCl2, carried out by a randomized complete block design (RCBD) with three replications. Cadmium stress caused a significant reduction of plant height and tillers hill-1 in a dose-dependent manner. The highest decline of relative water content and SPAD value was found at 1.5 mM (11 and 16%) and 2 mM (14 and 19%) Cd stress compared to the control. The number of effective tillers hill-1, filled grains panicle-1, 1000-grain weight, length of panicle, grain yield and straw yield reduced significantly by 44, 32, 15, 24, 37 and 45%, respectively, over the control. Germination and seedling-related parameters were recorded 10 days after germination. The lowest germination percentage (27%), germination index (27%) and seedling vigour index (49%) were observed at the highest level of Cd stress in comparison to the control. Cadmium stress resulted in maximum abnormal seedlings and markedly reduced length of root and shoot as well as their fresh and dry weight. Root shoot ratio showed differential responses to Cd stress. Thus, it can be concluded that a higher level of Cd in soil has a detrimental effect on seed germination, morphology, physiology and yield of rice.


1977 ◽  
Vol 89 (3) ◽  
pp. 589-597 ◽  
Author(s):  
A. B. McAllan ◽  
R. H. Phipps

SummaryThe (early maturing) maize hybrid, Anjou 210, was sown on 1 May (1975) and 50000 (LD) and 150000 (HD) plants/ha established. Leaf, stem, ear and husk components of the shoots, and whole shoots were separately examined for changes in dry weight, soluble sugars, starch, hemicellulose and cellulose at regular intervals from 104 to 154 days after planting together with whole shoots after ensiling.Throughout the sampling period whole shoot and ear dry weights increased steadily whereas those of leaf and stem decreased in plants from both treatments.Total soluble sugar contents for plants grown at LD were at a maximum 104 days after planting compared with 125 days after planting for the HD crop. Immediately prior to ensiling whole shoot soluble sugar content was 74 and 93 g/kg D.M. for LD and HD treatments respectively.Small amounts of starch (g/kg D.M.) were found in stems (10–25), husks (40–80) and leaves (17–35) of plants grown at both densities. The starch content of the ear increased from 57 to 390 g/kg D.M. and 168 to 376 g/kg D.M. in plants grown at LD and HD respectively.For plants from both treatments hemicellulose contents of husks, leaves and whole shoots increased with age whereas those of stems decreased. Cellulose contents did not vary greatly over the growing season.On ensiling plants from both densities, total soluble sugars had virtually disappeared after only 3 days. Apparent losses (approximately 0·3 g/g), over a longer period of time, were observed in hemicellulose sugars and starch. Apparent increases were observed in cellulose contents of approximately 0·15 g/g.


1980 ◽  
Vol 10 (3) ◽  
pp. 338-347 ◽  
Author(s):  
Hsu-Ho Chung ◽  
Robert L. Barnes

Research was conducted to study (1) seasonal changes in tissue composition and (2) dynamic allocation of photosynthate to different biochemical fractions in growing shoots of the current and previous years of 15-year-old loblolly pine (Pinustaeda L.). As the growing season progressed, the shoots increased rapidly in total biomass; however, old needles formed in the previous year lost dry weight. The most striking biochemical change was a rapid decrease in starch content of old needles early in the growing season. Soluble sugars and organic acids in old needles also decreased slightly. Contents of biochemical constituents generally increased in current axes and needles as the organs grew and increased in weight, although there were decreases in organic acid contents of current axes early in the growing season. Formation of nonlabile major constituents (cellulose, hemicelluloses, lignin, and protein) in current-year shoots proceeded at different rates. These rates were interpreted in terms of aspects of shoot growth and development. Seasonal allocation of photosynthates into biochemical constituent fractions in current year growth flushes was calculated. Results suggested that photosynthates were allocated to constituents of different functional categories (metabolism, storage, structure, and protection) at different times of the growing season in such a way that structural growth was of first priority. Thus, allocation of photosynthates to structural growth early in the season enables branches to compete for favorable growing conditions.


HortScience ◽  
1999 ◽  
Vol 34 (7) ◽  
pp. 1279-1285 ◽  
Author(s):  
D. Bradley Rowe ◽  
Frank A. Blazich ◽  
Robert J. Weir

Hedged stock plants of four full-sib families [27-2 × 27-5, 27-3 × 27-1, 27-2 × 27-1, and 27-6 × 27-1 (designated B, G, R, and W)] of loblolly pine (Pinus taeda L.) were fertilized daily with a complete nutrient solution containing N at 10, 25, 40, 55, or 70 mg·L–1. In May, terminal softwood stem cuttings were taken and placed under intermittent mist. Families were combined to form composite poor-rooting (BR) and good-rooting (GW) families. At 0, 3, 6, 9, and 12 weeks after sticking, cuttings were evaluated for rooting and analyzed for mineral nutrient and carbohydrate content. Percent rooting by week 12 for cuttings from stock plants receiving N between 25 to 70 mg·L–1 was 28% to 33%, whereas significantly fewer (17%) cuttings from plants receiving 10 mg·L–1 had rooted. By week 12, 98% of cuttings taken from stock plants receiving N at 10 mg·L–1 were alive, while significantly fewer (81% and 82%) of the more succulent cuttings receiving 55 and 70 mg·L–1, respectively, had survived. Nearly all increases in cutting height occurred within the first 3 weeks. In contrast, top dry weight increased steadily throughout the experiment. There were no significant differences in rooting between the two composite families until week 12, when 32% of cuttings from family GW had rooted compared with 24% for family BR. Survival of cuttings was greater for the poor-rooting family (BR) (94%) than for the good-rooting family (GW) (82%) after 12 weeks. Levels of total nonstructural carbohydrates (TNC) and individual soluble sugars were initially higher in cuttings taken from stock plants that received higher rates of N, whereas the reverse was true for starch content. With the exception of sucrose, content of TNC and soluble carbohydrates generally increased over time. Starch was nearly depleted by week 3, but had increased by weeks 6 and 9. No correlation was found between TNC: N ratios and rooting percentage. Family GW contained greater quantities of myo-inositol, glucose, fructose, sucrose, total soluble carbohydrates (TSC), and TNC than did family BR. Mineral nutrient content was generally greater in cuttings taken from stock plants that received higher rates of N; these cuttings also maintained higher levels throughout the 12-week rooting period. As with the soluble carbohydrates, the good-rooting composite family (GW) contained greater amounts of all mineral nutrients than did the poor-rooting family BR.


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