scholarly journals Phytoextraction by harvesting dead leaves: Cadmium accumulation associated with the leaf senescence in Festuca arundinacea

Author(s):  
Ling Fei ◽  
ShaoFan Zuo ◽  
JiaXin Zhang ◽  
ZhaoLong Wang

Abstract Phytoextraction strategy by harvesting dead leaves provides non-stop phytoremediation and a great saving in disposal cost of hazardous plant residues. This strategy is entirely dependent upon the amount of cadmium (Cd) accumulated in dead leaves. However, it is unknown that whether the leaf Cd accumulation is associated with its senescence and how to regulate its Cd accumulation. This study showed that Cd was preferentially and consistently distributed to and accumulated in the senescent leaves with the new leaf emergence and the old leaf dieback under 75 µM of Cd stress in tall fescue (Festuca arundinacea). Individual leaf monitoring from its emergence to senescence showed that Cd concentration increased exponentially with the leaf life cycle, while leaf biomass decreased gradually after 14 d of leaf emergence. The total amount of Cd accumulated in the leaf showed an exponential increase during leaf senescence, regardless of the leaf biomass loss. Our results demonstrated that leaf Cd accumulation was significantly associated with its senescence and the highest Cd accumulated in dead leaves could be contributed from the continuous Cd input during the leaf senescent process, indicating that further regulatory studies should be focused on the leaf senescence process to achieve higher Cd accumulation and phytoextraction efficiency by harvesting dead leaves.

2009 ◽  
Vol 54 (No. 1) ◽  
pp. 1-9 ◽  
Author(s):  
J. Száková ◽  
V. Zídek ◽  
D. Miholová

The influence of elevated cadmium content in diet on the content of this element in liver, kidney and testes of 68 male rats was studied in dependence on the chemical form of applied cadmium (as inorganic salt – CdCl<sub>2</sub> and organically bound in yeast cells); the influence of elevated arsenic content (as NaAsO<sub>2</sub>) in diet on its content in the same organs was also investigated. The interactions between arsenic and cadmium in the above-mentioned organs were studied. The addition of cadmium to the diet of rats significantly (<I>P</I> < 0.05) increased cadmium content in several organs. The addition of yeast containing the natural level of Cd increased the content of cadmium in liver and kidney of experimental animals significantly (<I>P</I> < 0.05). A significantly (<I>P</I> < 0.05) increased cadmium accumulation in organs was observed after the addition of Cd as CdCl<sub>2</sub>, compared with the addition of Cd as organically bound Cd in yeast cells. At the same time, the addition of yeasts containing the natural level of Cd decreased the Cd accumulation applied as CdCl2 in the examined organs. The addition of sodium arsenite to the diet of rats led to a significantly (<I>P</I> < 0.05) increased arsenic content in all the analyzed organs. The addition of yeasts to the diet increased arsenic content in liver and at the same time suppressed its content in kidneys of experimental animals. The interaction between arsenic and cadmium applied simultaneously was evident. The addition of As to the diet decreased the accumulation of Cd in kidney and increased its accumulation in testes. The addition of Cd to the diet increased arsenic content in liver and kidney and decreased its content in testes.


Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 904 ◽  
Author(s):  
Zhong-Wei Zhang ◽  
Yi-Ying Dong ◽  
Ling-Yang Feng ◽  
Zong-Lin Deng ◽  
Qiang Xu ◽  
...  

Oilseed rape (Brassica napus) is a Cadmium (Cd) hyperaccumulator. However, high-level Cd at the early seedling stage seriously arrests the growth of rape, which limits its applications. Brassica juncea had higher Cd accumulation capacity, but its biomass was lower, also limiting its applications. Previous studies have confirmed that Selenium (Se) can alleviate Cd toxicity. However, the regulatory mechanism of Se in different valence states of Cd accumulation was unclear. In this study, we investigated the ameliorating effects of three Se valence states, Na2SeO4 [Se(VI)], Na2SeO3 [Se(IV)] and Se-Met [Se(II)], to Cd toxicity by physiological and biochemical approaches in hydroponically-cultured Brassica juncea and Brassica napus seedlings. Although Se treatments slightly inhibited seedling Cd concentration, it tripled or quadrupled the Cd accumulation level per plant, because dry weight increased about four times more with Se and Cd application than with Cd treatment alone. Among the different valence states of Se, Se(II) had the most marked effect on reducing Cd toxicity as evidenced by decreased growth inhibition and Cd content. The application of Se(II) was effective in reducing Cd-induced reactive oxygen species accumulation, and promoted the antioxidant enzyme activity and photosynthesis of both Brassica species. In addition, Se(II) treatment increased the concentrations of Cd in the cell wall and soluble fractions, but the Cd concentration in the organelle part was reduced.


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 223 ◽  
Author(s):  
Xin Huang ◽  
Songpo Duan ◽  
Qi Wu ◽  
Min Yu ◽  
Sergey Shabala

Cadmium (Cd) is present in many soils and, when entering the food chain, represents a major health threat to humans. Reducing Cd accumulation in plants is complicated by the fact that most known Cd transporters also operate in the transport of essential nutrients such as Zn, Fe, Mn, or Cu. This work summarizes the current knowledge of mechanisms mediating Cd uptake, radial transport, and translocation within the plant. It is concluded that real progress in the field may be only achieved if the transport of Cd and the above beneficial micronutrients is uncoupled, and we discuss the possible ways of achieving this goal. Accordingly, we suggest that the major focus of research in the field should be on the structure–function relations of various transporter isoforms and the functional assessment of their tissue-specific operation. Of specific importance are two tissues. The first one is a xylem parenchyma in plant roots; a major “controller” of Cd loading into the xylem and its transport to the shoot. The second one is a phloem tissue that operates in the last step of a metal transport. Another promising and currently underexplored avenue is to understand the role of non-selective cation channels in Cd uptake and reveal mechanisms of their regulation.


2010 ◽  
Vol 113-116 ◽  
pp. 211-217
Author(s):  
Yin Qiu Zhang ◽  
Pei Dong Tai ◽  
Pei Jun Li ◽  
Qing Zhao ◽  
Dian Bo Dong

Hydroponic experiments were carried out to study the effects of cell division inhibitor (Maleic hydrazide MH) and protein synthesis inhibitor(Cycloheximide CHI)on Cd accumulation in Tagetes erecta L and their possible mechanisms. Seedlings were exposed to 4 mmol L-1 MH or 3 µmol L-1 CHI in 0.1 mg L-1 Cd-containing solution for 3 days. After treatment, the Cd content in leaves was significantly (P<0.05) reduced under MH or CHI treatment, which was consistent with the decreased soluble protein contents in leaves, suggesting that protein synthesis plays a role in Cd accumulation in leaves of Tagetes erecta L. Both of the plant growth inhibitors led to increased Cd contents in roots compared with the control, corresponding with increased GSH, Cys or γEC content under MH or CHI treatment, indicating that those S-containing compounds may be related to the increased Cd content in roots under the plant growth inhibitor treatments. On the other hand, the two inhibitors increased the citric acid content in all the tissues of Tagetes erecta L except for that in leaves under CHI treatment. All the results suggest that protein synthesis may be responsible for Cd accumulation in leaves of Tagetes erecta L, while the S-containing compounds and organic acids are associated with Cd absorption in roots of Tagetes erecta L.


2011 ◽  
Vol 71-78 ◽  
pp. 149-155
Author(s):  
Sha Sha Fu ◽  
Xin Fa Xu ◽  
Rong Fang Li ◽  
Pei Dong Tai

A hydroponic culture experiment was conducted to study the effect of temperature and nutrient level on Cd accumulation inTagetes erectaL.. In the first experiment, shoot Cd accumulation and transpiration rate at different temperature was determined. Cd accumulation was lower with higher transpiration rate at 35°C than that of 25°C or 15°C with lower transpiration rate. In the other experiment, cadmium accumulation of plants varies significantly under the condition of different nutrient supplication. Contents of Cd in roots were not high, but the contents of Cd in shoots were the highest when plants were cultivated in 0.05-fold Hoagland’s solution. Roots Cd accumulation decreased as the concentration of single nutrient element (N, P, S) decrease or absence, and shoots Cd accumulation decrease in the condition of sulfur deficiency and sulfur absence. It was shown that transpiration is not the primary factor affecting Cd accumulation inTagetes erectaL, but growth rate of plants has certain correlation with Cd accumulation; contents of Cd in roots are most affected by the supplication of nutrient elements, yet shoots accumulation is relatively lagging behind; different nutrient element has some different effect on Cd accumulation, and the effects of nitrogen and sulfur on the shoots Cd accumulation are the greatest.


RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 47584-47591 ◽  
Author(s):  
Yicheng Yin ◽  
Yaqin Wang ◽  
Yunguo Liu ◽  
Guangming Zeng ◽  
Xinjiang Hu ◽  
...  

A Cd-tolerant plant species named Boehmeria nivea (L.) Gaudich (ramie) was applied to study its Cd accumulation and translocation mechanisms with the addition of ethylene diamine tetracetic acid (EDTA) or nitrilotriacetic acid (NTA).


Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Li Tang ◽  
Jiayu Dong ◽  
Longtao Tan ◽  
Zhongying Ji ◽  
Yaokui Li ◽  
...  

AbstractCadmium (Cd)-contaminated rice is a serious issue affecting food safety. Understanding the molecular regulatory mechanisms of Cd accumulation in rice grains is crucial to minimizing Cd concentrations in grains. We identified a member of the low-affinity cation transporter family, OsLCT2 in rice. It was a membrane protein. OsLCT2 was expressed in all tissues of the elongation and maturation zones in roots, with the strongest expression in pericycle and stele cells adjacent to the xylem. When grown in Cd-contaminated paddy soils, rice plants overexpressing OsLCT2 significantly reduced Cd concentrations in the straw and grains. Hydroponic experiment demonstrated its overexpression decreased the rate of Cd translocation from roots to shoots, and reduced Cd concentrations in xylem sap and in shoots of rice. Moreover, its overexpression increased Zn concentrations in roots by up-regulating the expression of OsZIP9, a gene responsible for Zn uptake. Overexpression of OsLCT2 reduces Cd accumulation in rice shoots and grains by limiting the amounts of Cd loaded into the xylem and restricting Cd translocation from roots to shoots of rice. Thus, OsLCT2 is a promising genetic resource to be engineered to reduce Cd accumulation in rice grains.


1997 ◽  
Vol 122 (2) ◽  
pp. 267-274 ◽  
Author(s):  
G.A. Picchioni ◽  
P.H. Brown ◽  
S.A. Weinbaum ◽  
T.T. Muraoka

Estimates of leaflet and fruit macronutrient (N, P, K, Ca, and Mg) accumulation and resorption were developed in six (three heavily cropping, on-year and three noncropping, off-year) mature pistachio (Pistacia vera L. `Kerman') trees over three growing seasons during three stages of phenology [the spring growth flush (April to June); seed fill (late June to September); and leaf senescence (September to November)]. Crop load influenced total nutrient content per tree in annual organs (leaves and fruit), the relative allocation of nutrients between leaves and fruit, temporal patterns of nutrient accumulation in annual organs, and the magnitude of net leaf nutrient resorption per tree prior to leaf fall. In off-year trees, macronutrient accumulation in annual organs (leaves) was concentrated during the spring flush of growth. In contrast, significant macronutrient accumulation in annual organs of on-year trees (leaves plus fruit) occurred not only during the spring flush of growth but also during seed fill. Duration and magnitude of macronutrient accumulation were greater in on-year vs. off-year trees. Fruit N and P demand during seed fill was partially met by a net decrease in the N and P contents of the pericarp. These decreases in pericarp nutrient content during seed fill were equivalent to 32% and 26% of embryo accumulation of N and P, respectively. Fruit demand for N, P, and K during the spring flush of “on” years was accompanied by reduced leaf N, P, and K contents per tree. Net leaf N, Ca, and Mg resorption per tree during leaf senescence differed with crop load. Net leaf N resorption was significantly greater in off-year trees than on-year trees. Leaf N resorption presumably represents an important component of the N pool stored in perennial tree parts during dormancy. The greater leaf N resorption following “off” years was a function of greater leaf N concentration and greater leaf biomass per tree. In contrast, net leaf resorption of Ca and Mg was greater in on-year vs. off-year trees. Experimental validation of the magnitude and periodicity of nutrient uptake by mature pistachio trees is needed during the alternate-bearing cycle, especially in light of the potential contribution of current fertilization practices to groundwater contamination.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244085
Author(s):  
Mohammad Mazbah Uddin ◽  
Zhenfang Chen ◽  
Lingfeng Huang

Sesuvium portulacastrum is a well-known halophyte with considerable Cd accumulation and tolerance under high Cd stress. This species is also considered as a good candidate of Cd phytoremediation in the polluted soils. However, the mechanism of Cd accumulation, distribution and fractionation in different body parts still remain unknown. Seedlings of Sesuvium portulacastrum were studied hydroponically under exposure to a range of Cd concentrations (50 μM or μmol/L to 600 μM or μmol/L) for 28 days to investigate the potential accumulation capability and tolerance mechanisms of this species. Cd accumulation in roots showed that the bio-concentration factor was > 10, suggesting a strong ability to absorb and accumulate Cd. Cd fractionation in the aboveground parts showed the following order of distribution: soluble fraction > cell wall > organelle > cell membrane. In roots, soluble fraction was mostly predominant than other fractions. Cd speciation in leaves and stems was mainly contained of sodium chloride and deionised water extracted forms, suggesting a strong binding ability with pectin and protein as well as with organic acids. In the roots, inorganic form of Cd was dominant than other forms of Cd. It could be suggested that sodium chloride, deionised water and inorganic contained form of Cd are mainly responsible for the adaption of this plant in the Cd stress environment and alleviating Cd toxicity.


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