scholarly journals Main Controlling Factors and Empirical Models for Total Mercury and Methylmercury Accumulation in Rice (Oryza Sativa L.)

Author(s):  
Shuyang Du ◽  
Xingxiang Wang ◽  
Zhigao Zhou ◽  
Taolin Zhang ◽  
Muhammad Kamran ◽  
...  

Abstract It has been reported that rice consumption is the main mercury (Hg) exposure pathway for humans, and soil properties could significantly affect the methylation and accumulation process of Hg in soil-rice system. In this study, 19 paddy soil with various properties were spiked with exogenous Hg(II) at three concentration levels to conduct a pot experiment after a 60-days aging period. Stepwise multiple linear regression was applied to determine the controlling soil factors and develop prediction models for the methylmercury (MeHg) concentration in soil and total Hg (THg) and MeHg in brown rice. The results showed that THg in brown rice was positively correlated with THg in soil, while it had a negative correlation with soil pH and clay content. Soil organic matter (OM) promoted Hg methylation and inhibited the accumulation of MeHg in brown rice. Soil pH and clay content were negative factors when soil MeHg was used to predict MeHg in brown rice. THg and MeHg in brown rice could be well predicted by soil THg, pH and clay content. These results may provide a theoretical basis for safe production of rice in Hg contaminated paddy field.

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 685
Author(s):  
Enerand Mackon ◽  
Yafei Ma ◽  
Guibeline Charlie Jeazet Dongho Epse Mackon ◽  
Qiufeng Li ◽  
Qiong Zhou ◽  
...  

Anthocyanins belong to the group of flavonoid compounds broadly distributed in plant species responsible for attractive colors. In black rice (Oryza sativa L.), they are present in the stems, leaves, stigmas, and caryopsis. However, there is still no scientific evidence supporting the existence of compartmentalization and trafficking of anthocyanin inside the cells. In the current study, we took advantage of autofluorescence with anthocyanin’s unique excitation/emission properties to elucidate the subcellular localization of anthocyanin and report on the in planta characterization of anthocyanin prevacuolar vesicles (APV) and anthocyanic vacuolar inclusion (AVI) structure. Protoplasts were isolated from the stigma of black and brown rice and imaging using a confocal microscope. Our result showed the fluorescence displaying magenta color in purple stigma and no fluorescence in white stigma when excitation was provided by a helium–neon 552 nm and emission long pass 610–670 nm laser. The fluorescence was distributed throughout the cell, mainly in the central vacuole. Fluorescent images revealed two pools of anthocyanin inside the cells. The diffuse pools were largely found inside the vacuole lumen, while the body structures could be observed mostly inside the cytoplasm (APV) and slightly inside the vacuole (AVI) with different shapes, sizes, and color intensity. Based on their sizes, AVI could be grouped into small (Ф < 0.5 um), middle (Ф between 0.5 and 1 um), and large size (Ф > 1 um). Together, these results provided evidence about the sequestration and trafficking of anthocyanin from the cytoplasm to the central vacuole and the existence of different transport mechanisms of anthocyanin. Our results suggest that stigma cells are an excellent system for in vivo studying of anthocyanin in rice and provide a good foundation for understanding anthocyanin metabolism in plants, sequestration, and trafficking in black rice.


2021 ◽  
Vol 415 ◽  
pp. 125597
Author(s):  
Gaoxiang Huang ◽  
Changfeng Ding ◽  
Naijia Guo ◽  
Mingjun Ding ◽  
Hua Zhang ◽  
...  

2020 ◽  
Vol 12 (18) ◽  
pp. 7315
Author(s):  
Guandi He ◽  
Zhenming Zhang ◽  
Xianliang Wu ◽  
Mingyang Cui ◽  
Jiachun Zhang ◽  
...  

The content of heavy metals in the soil in Guizhou Province, which is a high-risk area for heavy metal exposure, is significantly higher than that in other areas in China. Therefore, the objective of this study was to evaluate the ability of CaCO3 and clay to accumulate heavy metals in topsoil sample collected from Lixisol using the method of indoor simulation. The results showed that the contents of Cu, Zn, Cd, Cr, Pb, Hg and As in the soil sample were 10.8 mg/kg, 125 mg/kg, 0.489 mg/kg, 23.5 mg/kg, 22.7 mg/kg, 58.3 mg/kg and 45.4 mg/kg, respectively. The soil pH values increased with the CaCO3 concentration in the soil, and the fluctuation of the soil pH values was weak after the CaCO3 concentrations reached 100 g/kg. The adsorption capacity of lime soil increased by approximately 10 mg/kg on average, and the desorption capacity decreased by approximately 300 mg/kg on average. The desorption of all heavy metals in this study did not change with increasing clay content. Pseudo-second-order kinetics were more suitable for describing the adsorption kinetics of heavy metals on the soil material, as evidenced by the higher R2 value. The Freundlich model can better describe the adsorption process of As on lime soil. The process of As, Cr, Cd and Hg adsorption on the soil sample was spontaneous and entropy-driven. Additionally, the process of Cu and Pb adsorption on the soil materials was spontaneous and enthalpy-driven. Generally, the adsorption and desorption of heavy metals in polluted soil increased and decreased, respectively, with increasing CaCO3 content. The effect of calcium carbonate on the accumulation of heavy metals in soil was greater than that of clay. In summary, CaCO3 and pH values in soil can be appropriately added in several areas polluted by heavy metals to enhance the crop yield and reduce the adsorption of heavy metals in soils.


2016 ◽  
Vol 25 (1) ◽  
pp. 335-339
Author(s):  
Hyun-seok Oh ◽  
Se Kwan Oh ◽  
Jum Seek Lee ◽  
June Seek Choi ◽  
Sung-Joon Lee

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Romaya Sitha Silitonga ◽  
Jumaria Nasution

ABSTRACT Black rice is very potential to be expanded because the content of anthocyanin, vitamin B1, and vitamin E black rice is higher than brown rice or white rice. At present, black rice producers are in Java, whereas in Sumatra, South Tapanuli District, Angkola Sub-District is a new type of black rice for rice farmers, so it is necessary to introduce and cultivate. The aims of the research was to determine the effect of chicken manure and paclobutrazol concentration on the tiller number and stems height of the rice plant in Batang Angkola District, South Tapanuli. This research method used was Randomized Block Design Factorial with two factors. The first factor was application of chicken manure (C) with dosage 0 g/pot 3 g/pot (C1), 6 g/pot (C2) and 9 g/pot (P3). The second factor was application paklobutrazol (P) with concentrations of 0 ppm (P0), 25 ppm (P1), 50 ppm (P2) and 75 ppm (P3). Statistical analysis used Anova 5%. If there is a difference followed by DMRT. The result showed that application of chicken manure at 9 g/pot (C3) and paclobutrazol 75 ppm (P3) were produce more tiller number and able to decrease height of black rice plant. Key words : Black Rice, Chicken manure, Paklobutrazol, South Tapanuli District, Tiller number, ABSTRAK Padi hitam sangat potensial dikembangkan karena kandungan antosianin, vitamin B1, dan vitamin E padi hitam lebih tinggi dari beras merah maupun beras putih. Adapun daerah penghasil beras hitam saat ini masih terdapat di daerah-daerah Pulau Jawa, sementara di Pulau Sumatera, khususnya di Kabupaten Tapanuli Selatan, Kecamatan Batang Angkola beras hitam masih tergolong tanaman padi jenis baru bagi para petani beras sehingga perlu dilakukan upaya perkenalan dan budidaya di daerah ini. Penelitian ini bertujuan mengetahui pengaruh konsentrasi kotoran ayam dan paclobutrazol terhadap jumlah anakan dan tinggi batang padi hitam yang tumbuh di Kecamatan Batang Angkola, Tapanuli Selatan. Metode penelitian yang digunakan adalah Rancangan Acak Kelompok Faktorial dengan 2 faktor. Faktor pertama, aplikasi Kotoran ayam (C) dengan dosis 0 g/pot (C0), 3 g/pot (C1), 6 g/pot (C2) dan 9 g/pot. Faktor kedua, paklobutrazol (P) dengan konsentrasi 0 ppm (P0), 25 ppm (P1), 50 ppm (P2) dan 75 ppm (P3). Data dianalisis menggunakan statistik analisis variansi pada taraf kesalahan 5%. Apabila ada beda nyata dilanjutkan dengan DMRT. Hasil penelitian aplikasi Kotoran ayam 9 g/pot (C3) dan paclobutrazol 75 ppm (P3) menghasilkan jumlah anakan lebih banyak dan dapat menekan pertumbuhan tinggi batang padi hitam yang ditanam. Kata Kunci : Jumlah anakan, Kabupaten Tapanuli Selatan, Kotoran Ayam, Paclobutrazol, Padi hitam.


2015 ◽  
Vol 12 (16) ◽  
pp. 13215-13240 ◽  
Author(s):  
W. Luo ◽  
P. N. Nelson ◽  
M.-H. Li ◽  
J. Cai ◽  
Y. Zhang ◽  
...  

Abstract. Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate containing soils and 1700 km sub-transect with non-carbonate containing soils) across northern China. Soil pHBC was greater in the carbonate containing soils than in the non-carbonate containing soils. Acid addition decreased soil pH in the non-carbonate containing soils more markedly than in the carbonate containing soils. Within the carbonate soil sub-transect, soil pHBC was positively correlated with cation exchange capacity (CEC), carbonate content and exchangeable sodium (Na) concentration, but negatively correlated with initial pH and clay content, and not correlated with soil organic carbon (SOC) content. Within the non-carbonate sub-transect, soil pHBC was positively related to initial pH, clay content, CEC and exchangeable Na concentration, but not related to SOC content. Carbonate content was the primary determinant of pHBC in the carbonate containing soils and CEC was the main determinant of buffering capacity in the non-carbonate containing soils. Soil pHBC was positively related to aridity index and carbonate content across the carbonate containing soil sub-transect. Our results indicated that mechanisms controlling pHBC differ among neutral-alkaline soils of northern China, especially between carbonate and non-carbonate containing soils, leading to different rates, risks, and impacts of acidification. This understanding should be incorporated into the acidification risk assessment and landscape management in a changing world.


2021 ◽  
pp. 1-12
Author(s):  
Manoj Menon ◽  
Amelia Smith ◽  
Joseph Fennell

Abstract Rice is consumed by nearly half of the global population and a significant source of energy and nutrients. However, rice consumption can also be a significant pathway of inorganic arsenic (iAs) exposure, thus requiring a risk–benefit assessment. This study assessed nutrient element (NE) densities in fifty-five rice types (white, brown and wild rice) marketed in the UK. Densities of essential NE were used to rank rice types in meeting daily NE targets under different consumption scenarios through a newly developed optimisation approach. Using iAs data from these rice types, we assessed the margin of exposure (MOE) for low (the UK) and high (Bangladesh) rice intake scenarios. Our results showed that brown and wild rice are significantly higher in many NE and significantly contribute to dietary reference value (DRV). Our modelling showed that switching to brown or wild rice could increase the intake of several essential nutrients by up to eight times that of white rice. Using rice consumption data for mid-to-high-consumption countries, we estimate that brown rice could provide 100 % adult DRV for Fe, Mg, Cr, P and Mo, and substantial contributions for Zn, Se and K. Our results show that the amount of rice primarily determines risk from iAs consumed rather than the type of rice. Therefore, switching from white to brown or wild rice could be beneficial, provided iAs concentration in rice is within the recommended limits.


2020 ◽  
Vol 457 (1-2) ◽  
pp. 339-354
Author(s):  
Kimberly Zitnick-Anderson ◽  
Luis E. del Río Mendoza ◽  
Shana Forster ◽  
Julie S. Pasche

Abstract Background and aims Field pea production is greatly impacted by multiple soil-borne fungal and oomycete pathogens in a complex. The objectives of this research were to 1) identify the soil-borne pathogens associated with field pea in North Dakota and; 2) develop prediction models incorporating the occurrence of the soil-borne pathogen communities, soil edaphic properties and disease incidence. Methods Soil and plants were sampled from 60 field pea fields in North Dakota during 2014 and 2015. Plants (1500 across two years) were rated for both root rot and soil-borne pathogens isolated from roots. Soils were analyzed for edaphic properties. Indicator species analysis was used to identify soil-borne pathogen communities. Logistic regression was used to determine associations and develop prediction models. Results Survey results from 2014 and 2015 indicated that the most prevalent soil-borne pathogens identified in field pea fields were Fusarium spp. and Aphanomyces euteiches. Five soil-borne pathogen communities were identified; three of which had statistically significant associations characterized by (1) Fusarium acuminatum, (3) A. euteiches, and (4) Fusarium sporotrichioides. The occurrence of the three communities were associated with clay content, soil pH, Fe2+, and K+. Disease incidence was associated with the presence of either community 1 or 3 and K+. Conclusions The results generated from this research will contribute to the development of management strategies by providing a soil-borne pathogen community prediction tool.


2017 ◽  
Vol 29 (2) ◽  
pp. 123-131
Author(s):  
Reshma Akter ◽  
Md Jamal Uddin ◽  
Md Faruque Hossain ◽  
Zakia Parveen

A study was carried out to evaluate the effects of brick manufacturing on phosphorus (P) and sulfur (S) concentrations in soil and plant collected from different distances of brick kilns in four AEZs of Bangladesh. Forty eight composite soil samples (0 - 15 cm depth) were collected from 48 points in 12 different sites at 0 m, 300 m, 800 m and 1500 m from brick kilns, where most (site 2, site 3, site 5, site 6, site 7, site 9 and site 10) of the brick kilns used coal for brick burning purposes. Plant samples (rice straw and different vegetables) were also collected from the respective fields except 0 m distances. Significantly (p ? 0.05) lower organic matter, cation exchange capacity, clay content and soil pH were found at 0 m distances compared to other distances. Highest concentration of total P in soil were recorded at 0 m distances and these concentrations decreased with increasing distances from the brick kilns in most of the sites; whereas available P is significantly lower at 0 m distances than that of other distances. Total and available concentration of S in soil followed the trend 0 m>300 m>800 m>1500 m. Maximum accumulation of P (69.15 mg kg-1) and S (0.14%) in plant was found at 800 m away from the brick kiln.Bangladesh J. Sci. Res. 29(2): 123-131, December-2016


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