Can Selenium and Molybdenum Restrain Cadmium Toxicity to Pollen Grains in Brassica napus?

Cadmium (Cd) is highly toxic, even at very low concentrations, to both animals and plants. Pollen is extremely sensitive to heavy metal pollutants; however, less attention has been paid to the protection of this vital part under heavy metal stress. A pot experiment was designed to investigate the effect of foliar application of Se (1 mg/L) and Mo (0.3 mg/L) either alone or in combination on their absorption, translocation, and their impact on Cd uptake and its further distribution in Brassica napus, as well as the impact of these fertilizers on the pollen grains morphology, viability, and germination rate in B. napus under Cd stress. Foliar application of either Se or Mo could counteract Cd toxicity and increase the plant biomass, while combined application of Se and Mo solutions on B. napus has no significant promotional effect on plant root and stem, but reduces the seeds’ weight by 10–11%. Se and Mo have decreased the accumulated Cd in seeds by 6.8% and 9.7%, respectively. Microscopic studies, SEM, and pollen viability tests demonstrated that pollen grains could be negatively affected by Cd, thus disturbing the plant fertility. Se and Mo foliar application could reduce the toxic symptoms in pollen grains when the one or the other was sprayed alone on plants. In an in vitro pollen germination test, 500 μM Cd stress could strongly inhibit the pollen germination rate to less than 2.5%, however, when Se (10 μM) or Mo (1.0 μM) was added to the germination medium, the rate increased, reaching 66.2% and 39.4%, respectively. At the molecular level, Se and Mo could greatly affect the expression levels of some genes related to Cd uptake by roots (IRT1), Cd transport (HMA2 and HMA4), Cd sequestration in plant vacuoles (HMA3), and the final Cd distribution in plant tissue at the physiological level (PCS1).

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Humic + Fulvic acid mitigated Cd adverse effects on plant growth, physiology and biochemical properties of garden cress

Scientific Reports ◽

10.1038/s41598-021-86991-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ertan Yildirim ◽

Melek Ekinci ◽

Metin Turan ◽

Güleray Ağar ◽

Atilla Dursun ◽

...

Keyword(s):

Heavy Metal ◽

Adverse Effects ◽

Plant Growth ◽

Fulvic Acid ◽

Pollution Level ◽

Hydroxyl Groups ◽

Cd Stress ◽

Garden Cress ◽

Cd Uptake ◽

Fresh Leaf

AbstractCadmium (Cd) is a toxic and very mobile heavy metal that can be adsorbed and uptaken by plants in large quantities without any visible sign. Therefore, stabilization of Cd before uptake is crucial to the conservation of biodiversity and food safety. Owing to the high number of carboxyl and phenolic hydroxyl groups in their structure, humic substances form strong bonds with heavy metals which makes them perfect stabilizing agents. The aim of this study was to determine the effects of humic and fulvic acid (HA + FA) levels (0, 3500, 5250, and 7000 mg/L) on alleviation of Cadmium (Cd) toxicity in garden cress (Lepidium sativum) contaminated with Cd (CdSO4.8H2O) (0, 100, and 200 Cd mg/kg) under greenhouse conditions. Our results showed that, Cd stress had a negative effect on the growth of garden cress, decreased leaf fresh, leaf dry, root fresh and root dry weights, leaf relative water content (LRWC), and mineral content except for Cd, and increased the membrane permeability (MP) and enzyme (CAT, SOD and POD) activity. However, the HA + FA applications decreased the adverse effects of the Cd pollution. At 200 mg/kg Cd pollution, HA + FA application at a concentration of 7000 mg/L increased the leaf fresh, leaf dry, root fresh, root dry weights, stem diameter, leaf area, chlorophyll reading value (CRV), MP, and LRWC values by 262%, 137%, 550%,133%, 92%, 104%, 34%, 537%, and 32% respectively, compared to the control. Although the highest H2O2, MDA, proline and sucrose values were obtained at 200 mg/L Cd pollution, HA + FA application at a concentration of 7000 mg/L successfully alleviated the deleterious effects of Cd stress by decreasing H2O2, MDA, proline, and sucrose values by 66%, 68%, 70%, and 56%, respectively at 200 mg/kg Cd pollution level. HA + FA application at a concentration of 7000 mg/L successfully mitigated the negative impacts of Cd pollution by enhanced N, P, K, Ca, Mg, Fe, Mn, Cu, Mn, Zn, and B by 75%, 23%, 84%, 87%, 40%, 85%, 143%, 1%, 65%, and 115%, respectively. In addition, HA + FA application at a concentration of 7000 mg/L successfully reduced Cd uptake by 95% and Cl uptake by 80%. Considering the plant growth parameters, the best results were determined when HA + FA concentration was 7000 mg/L. We have shown that, it is critical to apply a humic substance with high percentage of FA, which was 10% in this study, to mitigate the adverse effects of heavy metal stress on plant growth. In conclusion, the application of HA + FA may be suggested as an effective solution for reducing the Cd uptake of the plants by stabilizing Cd in soil and preventing translocation of Cd from the roots of plant to its shoot and leaves.

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Effect of Cadmium Toxicity on Growth, Oxidative Damage, Antioxidant Defense System and Cadmium Accumulation in Two Sorghum Cultivars

Plants ◽

10.3390/plants9111575 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1575

Author(s):

Muhammad Jawad Hassan ◽

Muhammad Ali Raza ◽

Sana Ur Rehman ◽

Muhammad Ansar ◽

Harun Gitari ◽

...

Keyword(s):

Heavy Metal ◽

Oxidative Damage ◽

Antioxidant Defense ◽

Cadmium Toxicity ◽

Antioxidant Defense System ◽

Agricultural Crop ◽

Cd Stress ◽

Defense System ◽

Cd Uptake ◽

Semi Arid

Heavy metal stress is a leading environmental issue reducing crop growth and productivity, particularly in arid and semi-arid agro-ecological zones. Cadmium (Cd), a non-redox heavy metal, can indirectly increase the production of reactive oxygen species (ROS), inducing cell death. A pot experiment was conducted to investigate the effects of different concentrations of Cd (0, 5, 25, 50, 100 µM) on physiological and biochemical parameters in two sorghum (Sorghum bicolor L.) cultivars: JS-2002 and Chakwal Sorghum. The results showed that various concentrations of Cd significantly increased the Cd uptake in both cultivars; however, the uptake was higher in JS-2002 compared to Chakwal Sorghum in leaf, stem and root. Regardless of the cultivars, there was a higher accumulation of the Cd in roots than in shoots. The Cd stress significantly reduced the growth and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2) concentration and malondialdehyde (MDA) content in both cultivars, but the Chakwal Sorghum showed more pronounced oxidative damage than the JS-2002, as reflected by higher H2O2, MDA and EL. Moreover, Cd stress, particularly 50 µM and 100 µM, decreased the activity of different antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). However, the JS-2002 exhibited higher SOD, POD and CAT activities than the Chakwal Sorghum under different Cd-levels. These findings revealed that JS-2002 had a stronger Cd enrichment capacity and also exhibited a better tolerance to Cd stress due to its efficient antioxidant defense system than Chakwal Sorghum. The present study provides the available information about Cd enrichment and tolerance in S. bicolor, which is used as an important agricultural crop for livestock feed in arid and semi-arid regions.

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Effect of Molybdenum on Plant Physiology and Cadmium Uptake and Translocation in Rape (Brassica napus L.) under Different Levels of Cadmium Stress

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17072355 ◽

2020 ◽

Vol 17 (7) ◽

pp. 2355

Author(s):

Zhangxiong Han ◽

Xuan Wei ◽

Dejun Wan ◽

Wenxiang He ◽

Xijie Wang ◽

...

Keyword(s):

Plant Physiology ◽

Chlorophyll Fluorescence ◽

Brassica Napus ◽

Cd Stress ◽

Brassica Napus L ◽

Cd Uptake ◽

P Values ◽

Leaf Chlorophyll ◽

Leaf Chlorophyll Fluorescence ◽

Cd Translocation

This study investigated the beneficial effect of molybdenum (Mo) application on rape plants (Brassica napus L.) grown in a soil polluted by cadmium (Cd). A pot experiment was conducted to determine how different concentrations of exogenous Mo (0, 50, 100, and 200 mg/kg) affect plant physiology, biomass, photosynthesis, cation uptake, and Cd translocation and enrichment in rape plants under Cd stress (0.5 and 6.0 mg/kg). Under single Cd treatment, plant physiological and biochemical parameters, biomass parameters, leaf chlorophyll fluorescence parameters, and macroelement uptake of rape plants decreased, while their malonaldehyde content, proline content, non-photochemical quenching coefficient, and Cd uptake significantly increased, compared to those of the control group (p-values < 0.05). High-Cd treatment resulted in much larger changes in these parameters than low-Cd treatment. Following Mo application, the accumulation of malondialdehyde and proline decreased in the leaves of Cd-stressed plants; reversely, the contents of soluble protein, soluble sugar, and chlorophyll, and the activities of superoxide dismutase and glutathione peroxidase, all increased compared to those of single Cd treatment (p-values < 0.05). Exogenous Mo application promoted shoot and root growth of Cd-stressed plants in terms of their length, fresh weight, and dry weight. The negative effect of Cd stress on leaf chlorophyll fluorescence was substantially mitigated by applying Mo. Exogenous Mo also improved the uptake of inorganic cations, especially potassium (K+), in Cd-stressed plants. After Mo application, Cd uptake and accumulation were inhibited and Cd tolerance was enhanced, but Cd translocation was less affected in Cd-stressed plants. The mitigation effect of Mo on Cd stress in rape was achieved through the immobilization of soil Cd to reduce plant uptake, and improvement of plant physiological properties to enhance Cd tolerance. In conclusion, exogenous Mo can effectively reduce Cd toxicity to rape and the optimal Mo concentration was 100 mg/kg under the experimental conditions.

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Pollen Quantity and Viability in 65 Litchi (Litchi chinensis Sonn.) Cultivars

HortScience ◽

10.21273/hortsci12193-17 ◽

2017 ◽

Vol 52 (10) ◽

pp. 1337-1341

Author(s):

Jiefang Wu ◽

Danwen Fu ◽

Jiezhen Chen ◽

Changhe Cai ◽

Qian Yan ◽

...

Keyword(s):

Developmental Stage ◽

Pollen Germination ◽

Germination Rate ◽

Pollen Grains ◽

Flowering Period ◽

Litchi Chinensis ◽

Development Stages ◽

Pollen Quantity ◽

Compatible Pollen

The characteristics of litchi pollen have drawn increasing attention in recent years. Previous studies indicated that there are significant differences in the quantity and viability of litchi pollen grains among different varieties and flowering stages. Moreover, the same variety may show a different quantity of pollen grains and viability in different years. There is still a lack of systematic studies on the change of pollen germination rate and pollen amount in different varieties and at different flowering stages. In this study, the changes in the germination rate of pollen at different development stages were studied. It was primarily revealed that the pollen germination rate already approached its peak upon the filament extends fully, but the anther does not dehisce the developmental stage. In 2009 and 2010, the viability and number of pollen grains per anther were investigated in 65 litchi cultivars, and a difference was observed among cultivars. The pollen germination rate ranged between 20.14% (‘Wuchali’) and 54.69% (‘Donlongmili’). The number of pollen grains per anther ranged between 1555 (‘Zhongshanzhuangyuanhong’) and 7455 (‘Houye’). Sixty-five litchi cultivars were classified into six clusters based on the pollen quantity and germination rate. Most litchi cultivars can produce large amounts of viable and compatible pollen grains during the flowering period. Thus, our results indicate that the pollen amount and germination rate might not be the only factors restricting the successful pollination of litchi.

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Yield of Winter Oilseed Rape (Brassica napus L. var. napus) in a Short-Term Monoculture and the Macronutrient Accumulation in Relation to the Dose and Method of Sulphur Application

Agronomy ◽

10.3390/agronomy12010068 ◽

2021 ◽

Vol 12 (1) ◽

pp. 68

Author(s):

Mariusz Stepaniuk ◽

Aleksandra Głowacka

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Foliar Application ◽

Soil Conditions ◽

Winter Oilseed Rape ◽

Brassica Napus L ◽

Soil Application ◽

Application Method ◽

Combined Application ◽

The Impact

The objective of this study was to assess the yield efficiency of sulphur-enhanced fertilisers, depending on the dose and application method, in a short-lived (three-year) monoculture of winter oilseed rape under the climate and soil conditions of south-eastern Poland. The experiment was carried out between 2010 and 2013 on winter oilseed rape (Brassica napus L. var. napus) of the Orlando variety, fertilised with different sulphur doses—0, 20, 40 or 60 kg S ha−1 applied in different method—soil application sowing, foliar application in the spring, and soil application sowing + foliar application in the spring (combined application). Following the harvest, seed and straw yields and the content of macroelements (N, S, P, K, Ca and Mg) in the seed and straw samples were determined. The harvest indices were also established for each of these elements. The impact of sulphur on winter oilseed rape yield depended significantly on both the dose and the application method. Even at the lowest dose (20 kg·ha−1), sulphur materially increased seed yield, regardless of the application method. With autumn soil application and foliar application, differences between the lowest dose and the higher doses (40 and 60 kg·ha−1) were not significant. However, with combined application, the highest dose (60 kg·ha−1) significantly increased yield compared to the lower doses. In general, all the fertilisation approaches significantly increased the N, P, K, Ca and Mg contents compared to the control sample, but the differences between them were not substantial. Each of the sulphur application approaches decreased the harvest index for sulphur. The foliar application of each of the doses decreased the harvest indices for N, P, K and Ca. The soil application of 20 kg·ha−1, and the mixed application of 40 and 60 kg·ha−1, all increased the harvest indices for P, K and Ca.

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Assessment of pollen viability and germination in Swainsona formosa (G.Don) J.Thompson

Biospecies ◽

10.22437/biospecies.v12i1.6596 ◽

2019 ◽

Vol 12 (1) ◽

pp. 49-54 ◽

Cited By ~ 1

Author(s):

Zulkarnain Z

Keyword(s):

Pollen Tube ◽

Pollen Germination ◽

Proper Time ◽

Sucrose Concentration ◽

Germination Rate ◽

Pollen Viability ◽

Pollen Grains ◽

Tube Formation ◽

Viability Assessment

The work presented here was aimed at investigating the proper time (after spreading) for viability assessment and the effect of various sucrose concentrations on pollen germination in Swainsona formosa. The rate of pollen tube formation was determined for freshly shed pollen grains of glasshouse-grown plants at 10, 15, 20, 25, 30, 60 and 120-minute intervals after being plated on Brewbaker and Kwack (BK) medium. The results indicated that within 60 minutes pollen germination reached 63.70%, after which remained steady at 120 minutes (63.71%). Under the effect of various concentrations of sucrose, i.e. 0.5, 10, 15, and 20% (w/v), the germination rate of pollen grains was assessed at 60 minutes following germination. The results showed that sucrose concentration of 10 – 15% (w/v) produced better germination rate (64.14%) compare to lower concentrations (19.64 and 43.58% at zero and 5% sucrose, respectively). Sucrose concentration above 15% was also found to inhibit pollen germination (48.92% at sucrose concentration of 20%).

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Fertility analyses of interspecific hybrids between Lagerstroemia indica and L. speciosa

Czech Journal of Genetics and Plant Breeding ◽

10.17221/174/2017-cjgpb ◽

2019 ◽

Vol 55 (No. 1) ◽

pp. 28-34

Author(s):

Yi-Qian Ju ◽

Xing Hu ◽

Yao Jiao ◽

Yuan-Jun Ye ◽

Ming Cai ◽

...

Keyword(s):

Pollen Germination ◽

Germination Rate ◽

Embryo Rescue ◽

Pollen Grains ◽

Female Parent ◽

Interspecific Crosses ◽

Apparent Difference ◽

Breeding Programs ◽

Germination Ability ◽

Sterile Hybrids

Interspecific crosses play an important role in gene introgression, plant improvement and speciation. However, poor fertility of F<sub>1</sub> generation was commonly found, which hampered backcrossing and ideal progeny generation. To explore useful materials for further breeding programs, sterile hybrids (DD1, FD1, ZD3) from different cross combinations of Lagerstroemia indica and L. speciosa and the fertile hybrid (ZD6) were selected. The results showed that pollen grains of sterile hybrids had no germination ability while ZD6 showed 25.90% pollen germination rate. The morphology of stigmas and their papilla cells showed no apparent difference. Normal pollen tubes could be detected in ovaries of ZD6 and ZD3 24 h after pollination. However, the enlarged ovaries of ZD3 began to abscise at 72 h after pollination, which suggested that the barriers occurred during post-fertilization phases. As a consequence, ZD6 can be used as either male or female parent for further Lagerstroemia breeding programs, while the sterile hybrids may be used as female parent through embryo rescue culture.

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Alleviation of Cadmium Phytotoxicity Using Silicon Fertilization in Wheat by Altering Antioxidant Metabolism and Osmotic Adjustment

Sustainability ◽

10.3390/su132011317 ◽

2021 ◽

Vol 13 (20) ◽

pp. 11317

Author(s):

Abdihakim Osman Heile ◽

Qamar uz Zaman ◽

Zubair Aslam ◽

Afzal Hussain ◽

Mustansar Aslam ◽

...

Keyword(s):

Foliar Application ◽

Food Contamination ◽

Growth Period ◽

Potassium Silicate ◽

Cd Stress ◽

Cd Uptake ◽

Rapid Action ◽

Silicon Fertilization ◽

Metabolic Activities ◽

The Given

Humans are facing very serious health threats from food contamination with cadmium (Cd), and Cd uptake by wheat is amongst the main causes of Cd entrance into the food chain. The current study examined the effect of foliar application (0, 1.50, 3.00 and 4.00 mM) of various silicate chemicals (calcium silicate and potassium silicate) on wheat growth and Cd addition by wheat under Cd stress 20 mg kg−1 of soil using CdCl2. The results revealed that under control conditions, the application of Si improved all the growth, physiological, biochemical and quality attributes by reducing malondialdehyde contents and electrolyte leakage. Under Cd stress, the supplementation of Si conferred a better growth rate, gaseous exchange for metabolic activity and maintained the tissues’ turgor and membranes’ stabilities compared to those obtained under control (without Si). The enzymatic activities (superoxide dismutase, peroxidase and catalase) also show rapid action by the application of Si supplement, which were associated with elevated osmoprotectant contents and antioxidants, having role in antioxidant defense against Cd stress. These results suggested that a 4.50 mM concentration of Si supplement (potassium silicate) works effectively against Cd stress. The given results showed that Si supplement is beneficial for the enhancement of many metabolic activities that takes places in plants during the growth period that proved a feasible approach in controlling the Cd concentration within wheat plants and, ultimately, in humans.

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Pollen Germination Potential Influences by Carbohydrates and Proteins in Pollen Grains of Asian Pear

HortScience ◽

10.21273/hortsci.39.4.762a ◽

2004 ◽

Vol 39 (4) ◽

pp. 762A-762

Author(s):

Wol-Soo Kim* ◽

Sang-Hyun Lee

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Germination ◽

Germination Rate ◽

Pollen Viability ◽

Pollen Grains ◽

Tube Growth ◽

Con A ◽

Asian Pear ◽

Pollen Surface

In order to investigate the cause of differences of mature pollen in Asian pear (Pyrus phyfolia) that are collected from various sources for the artificial pollination, various factors were measured as below: the composition of nonstructural carbohydrate in bud at 30 days after full bloom, the contents of crude protein in skin, cytosol and membrane, and the affinity for lectin (CON-A: Concanavalin, type III A) of glycoprotein in cytosol of pollen were measured. Contents of sucrose and glucose in buds influenced pollen germination rate and pollen tube growth, respectively. Therefore, soluble types of carbohydrates stored in bud were regarded as influencing on pollen germination rate and pollen tube growth. Pollen, which showed low activity, had low affinity on CON-A, lectin of glycoprotein, because it had fragile membrane, proteins in cells were denatured to pollen surface and certain enzymes concerned in pollen germination lost stability and activity. Pollens that showed high activity contained 92 kDa protein while others not. This was assumed as influencing on control of pollen viability.

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Germination Characteristics and Dynamic Changes of Antioxidant Enzymes during Storage of Viola dissecta Pollen

International Journal of Agriculture and Biology ◽

10.17957/ijab/15.1736 ◽

2021 ◽

Vol 25 (04) ◽

pp. 838-844

Author(s):

Wenqing Jia

Keyword(s):

Antioxidant Enzymes ◽

Pollen Germination ◽

Room Temperature ◽

Storage Temperature ◽

Germination Rate ◽

Pollen Grains ◽

Suitable Medium ◽

Different Temperatures ◽

Surface Ornamentation

Knowledge about pollen ultra-morphology, storage characteristics and germination rate are essential for directional plant breeding and plant improvement. The objective of this study was to determine a suitable medium for pollen germination in vitro of Viola dissecta and to evaluate the effect of different storage temperatures on its pollen longevity. The pollen ultra-morphology of V. dissecta was observed using scanning electron microscopy (SEM), the suitable medium for pollen germination in vitro was determined by orthogonal test. Dried pollen of V. dissecta was stored at different temperatures (room temperature, 4, -20 and -80°C) and different storage times (24, 40, 72, 120, 184, 264 and 365 d), the germination rate of the stored pollen and the activities of SOD, POD and CAT were investigated. Pollen grains of V. dissecta were medium-sized with three germination ditches. The surface ornamentation was smooth with small grains set on the surface, which was different from Viola spp. pollen. The most suitable medium for V. dissecta was composed of 285 g•L-1 sucrose, 6 g•L-1 agar, 50 mg•L-1 GA3, 250 mg•L-1 boric acid, and 200 mg•L-1 Ca(NO3)2, The best storage temperature of pollen was -80oC, after 365 d of storage, the germination rate was still 57.86%. During storage, the pollen germination rate decreased significantly after the peak of the activities of the three antioxidant enzymes. Correlation analysis showed that SOD was major factor affecting the germination rate of V. dissecta pollen, and it has a significant positive correlation with pollen germination rate, followed by CAT and POD. SOD was a sensitive antioxidant enzyme at room temperature, 4 and -80°C, whereas at -20°C, both SOD and CAT were sensitive antioxidant enzymes. © 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers © 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers©

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