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1.
Ying Yong Sheng Tai Xue Bao ; 32(3): 921-930, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754558

RESUMEN

Fertilization is an effective way to improve soil quality, increase soil fertility and soil microbial diversity in paddy soil. To explore the changes of soil labile organic carbon (C) fractions and hydrolytic enzyme activity after 34 years fertilization treatments in a field experiment in double-cropping rice system of southern China. There were four treatments, including chemical fertilizer alone (MF), rice residue and chemical fertilizer (RF), 30% organic matter and 70% chemical fertilizer (OM), and the control without fertilizer input (CK). We measured soil organic carbon (SOC) content, soil labile organic C fractions, SOC related hydrolytic enzyme activity, correlation coefficients of soil enzyme activity with SOC content and its labile organic C fractions. The results showed that MF, RF and OM increased SOC content by 4.5%, 22.4% and 53.5%, respectively. Compared with MF and CK, RF and OM increased soil labile organic C fractions [cumulative C mineralization (Cmin), permanganate oxidizable C (KMnO4-C), particulate organic C (POC), dissolved organic C (DOC), light fraction organic C (LFOC), microbial biomass C (MBC)] and the proportion of each labile organic C fractions to total organic C. The contents of Cmin, KMnO4-C, POC, DOC, LFOC and MBC under OM treatment were 3.5, 3.1, 3.7, 1.9, 1.2 and 1.9 times higher than CK treatment, respectively. The proportion of labile organic C fractions to total organic C of RF and OM treatments was significantly higher than that in CK. The order of soil hydrolytic enzyme activity [α-glucosidase (αG), ß-glucosidase (ßG), ß-xylosidase (ßX), cellobiohydrolase (GBH), and N-acetyl-ß-glucosaminidase (NAG)] was OM>RF>MF>CK. The soil hydrolytic enzyme activity under OM treatment increased by 111.8%, 14.1%, 127.3%, 285.6% and 91.4% compared with CK, respectively. Furthermore, RF and OM treatments were beneficial to soil peroxidase (POD) activity. MF treatment was beneficial to soil polyphenol oxidase (PPO) activity. There was a significant positive correlation between soil hydrolytic enzyme activity and SOC content and its labile organic C fractions. In conclusion, the combined application of organic manure, rice straw returning and chemical fertilizer is an effective method to improve soil labile organic C fractions and hydrolytic enzyme activity in a double-cropping rice paddy field of southern China.


Asunto(s)
Fertilizantes , Oryza , Agricultura , Carbono/análisis , China , Fertilizantes/análisis , Suelo
2.
Ying Yong Sheng Tai Xue Bao ; 32(3): 942-950, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754560

RESUMEN

The strategy of few or no-phosphorus fertilization in rice season but more in wheat season can effectively increase phosphorus use efficiency and reduce phosphorus loss through runoff and leaching. It remains unknown whether the lack of phosphorus will affect greenhouse gas emission in the rice season. We monitored the CH4 and N2O emission fluxes during the growth period of rice treated with normal phosphorus application (NPK) and no-phosphorus application (NK) in two long-term experimental fields in Suzhou and Yixing. The results showed that long-term no-phosphorus application promoted CH4 and N2O emission in both fields. Compared with the NPK treatment, CH4 and N2O emissions from the NK treatment significantly increased by 57% and 25% in Suzhou experi-mental field, respectively, while those in Yixing experimental field were also significantly increased by 221% and 70%, respectively. The contents of organic acid, dissolved organic carbon and available phosphorus in soil were reduced under long-term NK treatment, and they were closely related to CH4 emission. Soil available phosphorus content was significantly negatively correlated with CH4 emission (r=-0.987). The global warming potential (GWP) was greater in NK treatment than NPK treatment in both fields. Therefore, long-term no-phosphorus application could decrease the contents of organic acid, soluble organic carbon, and available phosphorus in soils, resulting in more CH4 and N2O emission in rice field.


Asunto(s)
Gases de Efecto Invernadero , Oryza , Agricultura , China , Fertilización , Fertilizantes , Gases de Efecto Invernadero/análisis , Metano/análisis , Óxido Nitroso/análisis , Fósforo , Suelo
3.
Ying Yong Sheng Tai Xue Bao ; 32(3): 1096-1104, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754577

RESUMEN

Silicon (Si) application could significantly alleviate the toxic effects of cadmium (Cd) on the growth and development of rice. Here, we examined the regulatory effects of Si on Cd accumulation and stress response in rice seedlings through a hydroponic root separation test. The results showed that the biomass of rice seedlings decreased significantly under Cd stress, while the addition of Si could alleviate such negative effect. The uptake, transfer, and accumulation of Cd in rice seedling were significantly affected by Si addition under Cd stress. Si application under the unilateral Cd stress (Si-Cd+Si, Si-Cd) increased Cd-retention coefficient of root by 83.3%-83.6%, which restricted the transfer of Cd from root to aboveground. However, the treatment with Si added to the non-stressed side (Si-Cd) elevated the uptake and accumulation of Cd in rice seedling, with the accumulation in root being increased by 48.2% when compared to the treatment under the unilateral Cd stress without the addition of Si (CK-Cd). The treatment with Si added in two sides (Si-Cd+Si) decreased the uptake of Cd both in root and aboveground parts by 36.7% and 54.9%, respectively. The addition of Si under bilateral Cd stress (Cd-Cd+Si) significantly reduced the Cd uptake of both the root and aboveground parts by 57.8% and 46.5%, respectively, compared to the treatment of bilateral Cd stress (Cd-Cd). Higher Si concentration in rice seedling was found under the Cd stress. More Si was accumulated in rice seedling to resist the Cd stress when Si was added. The addition of Si affected the absorption of other metal elements in rice seedlings, including calcium (Ca), magnesium (Mg) and manganese (Mn). The concentrations of Ca and Mg in root and aboveground parts were significantly increased by Si addition under bilateral Cd-stress (Cd-Cd+Si), but Mn concentration was changed with the stress degree of Cd. The activities of superoxide dismutase (SOD) and peroxidase (POD) in root were affected by Si under Cd stress, especially for the Si-Cd treatment. The activity of POD in the root of the Cd-stress side and that of SOD in non-stress side were significantly increased, which benefit to scavenging the free radicals induced by Cd stress. In conclusion, Si could regulate the growth of rice seedlings, the uptake of elements such as Cd and Si, and the antioxidant reaction of the root system under the Cd stress. High Si concentration in plant is conducive to enhancing Cd tolerance.


Asunto(s)
Oryza , Contaminantes del Suelo , Cadmio/toxicidad , Estrés Oxidativo , Raíces de Plantas , Plantones , Silicio/farmacología , Contaminantes del Suelo/toxicidad
4.
Sci Total Environ ; 772: 145554, 2021 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-33770853

RESUMEN

To understand the effect mechanisms of iron plaque and fatty acids on the migration of PBDEs from soil to rice (Oryza sativa), pot experiments were conducted in the soil spiked with decabromodiphenyl ether (BDE-209) under the conditions of tourmaline and nano-goethite Fenton-like treatments. The results showed that iron mineral Fenton-like oxidation could effectively remove BDE-209 from rhizosphere soil, the highest removal rate obtained 89.29% with the addition of 0.4 mmol/L H2O2 and 8 g nano-goethite (G + 3H group). Iron mineral Fenton-like oxidation could produce iron plaque (IP) on rice roots and accumulate a part of contaminants on the surface of IP, further weakening BDE-209 uptake in the plants. Additionally, the occurrence of fatty acid variation induced by BDE-209 stress, iron mineral Fenton-like oxidation at high concentrations of H2O2 with 0.4 mmol/L affected the distribution of fatty acids in plant tissues, especially for C18:0 fatty acid. While the IP on rice roots prevented the BDE-209 into plant, it was also closely related to the distribution of fatty acids in rice, altering BDE-209 accumulation in the rice. To safely use the iron mineral Fenton-like oxidation in the agricultural soil remediation, the safety of plant cells treated by mineral Fenton-like oxidation was evaluated using the transmission electron microscopy (TEM) and enzyme activity determination, which indicated that iron mineral Fenton-like oxidation would destroy the inner structures of plant cells, especially for G + 3H group.


Asunto(s)
Oryza , Contaminantes del Suelo , Ácidos Grasos , Éteres Difenilos Halogenados/análisis , Peróxido de Hidrógeno , Hierro/análisis , Minerales , Raíces de Plantas/química , Suelo , Contaminantes del Suelo/análisis
5.
Ying Yong Sheng Tai Xue Bao ; 32(2): 564-570, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33650366

RESUMEN

To explore the mechanism of exogenous organic materials enhancing soil organic carbon and soil fertility, based on a long-term experiment located in Hengyang Red Soil Experimental Station, we examined the effects of winter green manure and straw returning patterns (CK, winter fallow; MV, winter Chinese milk vetch; S, early-season rice straw total returning; DS, early-season and late-season rice straw total returning; SMV, winter Chinese milk vetch + early-season rice straw total returning; DSMV, winter Chinese milk vetch + early-season and late-season rice straw total returning) on soil aggregates and organic functional groups. The results showed that the proportion of super aggregates (>2 mm) and macroaggregates (0.25-2 mm) in double cropping rice soil was the highest with a ratio of about 72.1%-81.8%, and the organic carbon content in the two kinds of aggregates was as high as 12.1-20.7 g·kg-1, accounting for 22.7%-59.0% of the total organic carbon. The main organic functional group in paddy soil was polysaccharides, followed by aliphatic carbon and aromatic carbon. The abundance of all those groups was affected by winter Chinese milk vetch growing and straw returning. Compared with other treatments, DSMV significantly increased the proportion of super aggregates (>2 mm) and macroaggregates (0.25-2 mm) and favored the accumulation of inert carbon such as aromatic carbon in the two kinds of aggregates. DSMV could enhance the stability of soil aggregates and organic matter, which had high potential in the real agricultural production.


Asunto(s)
Oryza , Suelo , Agricultura , Carbono , Estiércol , Estaciones del Año
6.
Nat Commun ; 12(1): 1392, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33654102

RESUMEN

Rice grains typically contain high levels of toxic arsenic but low levels of the essential micronutrient selenium. Anthropogenic arsenic contamination of paddy soils exacerbates arsenic toxicity in rice crops resulting in substantial yield losses. Here, we report the identification of the gain-of-function arsenite tolerant 1 (astol1) mutant of rice that benefits from enhanced sulfur and selenium assimilation, arsenic tolerance, and decreased arsenic accumulation in grains. The astol1 mutation promotes the physical interaction of the chloroplast-localized O-acetylserine (thiol) lyase protein with its interaction partner serine-acetyltransferase in the cysteine synthase complex. Activation of the serine-acetyltransferase in this complex promotes the uptake of sulfate and selenium and enhances the production of cysteine, glutathione, and phytochelatins, resulting in increased tolerance and decreased translocation of arsenic to grains. Our findings uncover the pivotal sensing-function of the cysteine synthase complex in plastids for optimizing stress resilience and grain quality by regulating a fundamental macronutrient assimilation pathway.


Asunto(s)
Arsénico/metabolismo , Oryza/metabolismo , Semillas/metabolismo , Selenio/metabolismo , Azufre/metabolismo , Alelos , Cloroplastos/metabolismo , Cisteína Sintasa/metabolismo , Redes y Vías Metabólicas , Modelos Biológicos , Mutación/genética , Fenotipo , Fitoquelatinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Serina/metabolismo , Fracciones Subcelulares/metabolismo
7.
Sci Total Environ ; 771: 144764, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33736157

RESUMEN

Heavy metals like Cr (VI), when released into the environment, pose a serious threat to animal and human health. In this study, iron and (3-Aminopropyl)triethoxysilane (APTES) biochar composites were prepared from the biochar, which was produced through the pyrolysis of rice straw at 400 and 600 °C, using the chemical processes with an aim that the doping of pristine biochar structure with the Fe and NH2 radicals would enhance the removal of Cr (VI) and Zn (II) adsorption in both aqueous solution and soil. Both biochar composites were mixed at a rate of 3% (w/w) with the mine soil for the soil incubation test, and after completion of the test, a soil fertility index (SFI) was calculated. Results showed that both iron and APTES biochar composites followed the Langmuir-Freundlich isotherm showing the maximum removal capacity of 100.59 mg/g for Cr (VI) by APTES/SiBC 600 and maximum adsorption capacity of 83.92 mg/g for Zn2+ by Fe/BC 400. The SFI of the mine-soil amended with both Fe and APTES biochar composites were 16.67 and 13.04%, respectively higher than the controlled study. The mitotic index of the A. cepa cells that grew up in the soil amended with Fe/BC and APTES/SiBC were 40.47 and 44.45%, respectively, higher than the controlled study. The results indicated that the incorporation of the Fe and APTES biochar composites in the soil effectively reduced the metal toxicity and improved the soil physicochemical properties. This study opens up the prospects of using biochar composites in contaminated soil and water treatments.


Asunto(s)
Metales Pesados , Oryza , Contaminantes del Suelo , Adsorción , Carbón Orgánico , Humanos , Hierro , Metales Pesados/análisis , Extractos Vegetales , Propilaminas , Silanos , Suelo , Contaminantes del Suelo/análisis , Zinc
8.
Sci Total Environ ; 771: 145408, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33736169

RESUMEN

The accumulation of antimony (Sb) by rice is a severe threat to exposed populations. Previous studies demonstrated that, compared to flooded (anaerobic) water management, dry cultivation management (aerobic) could substantially decrease As, an analog of Sb, uptake by rice. However, the effects of different water management strategies on the accumulation of Sb by rice are less understood. It is proposed that microorganisms play an important role in regulating Sb mobility in rice paddies. Hence, the current study compared the microbial communities in rice paddies receiving different water management, i.e., flooded (anaerobic) and dry (aerobic)) rice cultivation. Significant decrease in Sb uptake by rice, in both the roots and grains, was observed under the aerobic compared to the anaerobic conditions. This could partially be attributed to the differences in the microbial communities as shaped by the redox environment. In aerobic soils, the gene responsible for Sb oxidation (i.e., aioA) was significantly, while in anaerobic soils the gene responsible for Sb reduction (i.e., arrA) was enriched, suggesting that variation in redox conditions may trigger different microbial responses. Accordingly, geochemical analysis indicated that accumulation of Sb(III) was only observed under anaerobic conditions, but not under aerobic conditions. The environment-microbe interactions were distinct between the two treatments with a greater number of interactions between Sb fractions and the microbial assemblage under anaerobic conditions, while Eh was the most influential geochemical parameter under aerobic conditions. Finally, the presence of a core microbiome under the two conditions suggested the possibility of microorganisms that support rice growth, nutrition, and health. The reduction of Sb in rice grain significantly decreases Sb exposure to the residents in Sb contaminated regions, and should be considered for future rice cultivation practices.


Asunto(s)
Arsénico , Microbiota , Oryza , Contaminantes del Suelo , Anaerobiosis , Antimonio/análisis , Arsénico/análisis , Monitoreo del Ambiente , Suelo , Microbiología del Suelo , Contaminantes del Suelo/análisis
9.
Yi Chuan ; 43(3): 271-279, 2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33724211

RESUMEN

LRXs (leucine-rich repeat extensins) are chimeric cell wall proteins containing an N-terminal leucine-rich repeat (LRR) and a C-terminal extensin domain. Increasing evidences suggest that LRXs family genes play important roles in pollen germination and pollen tube growth in Arabidopsis thaliana. However, the functions of rice (Oryza sativa L.) LRX genes in pollen development remain poorly understood. Bioinformatics analysis showed that the rice LRX gene family consist of eight members, namely OsPEX3, OsLRX3 and OsLRX5 located on chromosome 1, OsLRX1, OsLRX3, OsLRX2,OsPEX1 and OsPEX2 located on chromosome 2, 5, 6, 11 and 12, respectively. The OsPEX1 gene is preferentially expressed in rice anther, suggesting that it may be involved in the regulation of pollen development. Next, we further investigated the role of the OsPEX1 gene in rice by knockdown of its expression using an RNAi approach. The OsPEX1 RNAi transgenic lines showed a significant decrease in seed setting rate (10%~30%) due to pollen sterility. Further quantitative RT-PCR analysis indicated that the OsPEX1 gene was significantly down-regulated in the RNAi transgenic lines. The results indicate that the OsPEX1plays an important role in the regulation of rice pollen development. Further studies on this gene could provide insights on the molecular and genetic mechanisms in this developmental process.


Asunto(s)
Oryza , Pared Celular/metabolismo , Fertilidad , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/genética
10.
Molecules ; 26(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670642

RESUMEN

We investigated the relationship between the blue-light photoreceptor cryptochrome (CRY) and melatonin biosynthesis by generating RNA interference (RNAi) transgenic rice plants that suppress the cryptochrome 1b gene (CRY1b). The resulting CRY1b RNAi rice lines expressed less CRY1b mRNA, but not CRY1a or CRY2 mRNA, suggesting that the suppression is specific to CRY1b. The growth of CRY1b RNAi rice seedlings was enhanced under blue light compared to wild-type growth, providing phenotypic evidence for impaired CRY function. When these CRY1b RNAi rice plants were challenged with cadmium to induce melatonin, wild-type plants produced 100 ng/g fresh weight (FW) melatonin, whereas CRY1b RNAi lines produced 60 ng/g FW melatonin on average, indicating that melatonin biosynthesis requires the CRY photoreceptor. Due to possible feedback regulation, the expression of melatonin biosynthesis genes such as T5H, SNAT1, SNAT2, and COMT was elevated in the CRY1b RNAi lines compared to the wild-type plants. In addition, laminar angles decreased in the CRY1b RNAi lines via the suppression of brassinosteroid (BR) biosynthesis genes such as DWARF. The main cause of the BR decrease in the CRY1b RNAi lines seems to be the suppression of CRY rather than decreased melatonin because the melatonin decrease suppressed DWARF4 rather than DWARF.


Asunto(s)
Vías Biosintéticas/genética , Brasinoesteroides/biosíntesis , Criptocromos/genética , Genes de Plantas , Melatonina/biosíntesis , Oryza/genética , Tolerancia a la Sal/genética , Vías Biosintéticas/efectos de los fármacos , Criptocromos/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Oryza/efectos de los fármacos , Fenotipo , Plantas Modificadas Genéticamente , Interferencia de ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Tolerancia a la Sal/efectos de los fármacos , Plantones/efectos de los fármacos , Plantones/genética , Serotonina/metabolismo , Cloruro de Sodio/farmacología
11.
Carbohydr Polym ; 260: 117789, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712137

RESUMEN

Cellulose was extracted from rice husk (RH) using an integrated delignification process using alkaline treatment and acid hydrolysis (concentrated HNO3) for lignocellulosic biomass dissolution. Cellulose yield and quality were assessed through analysis of lignocellulosic content, thermogravimetric, functional group, X-ray diffraction, and surface morphology. HNO3 treatment showed an increment (2.01-fold) in the cellulose content and some enhancement in the crystallinity of cellulose (up to 40.8%). A slight increase was observed in thermal properties from 334.6 °C to 339.3 °C. Economic analysis showed chlorine extraction produce higher cellulose recovery (58%) as compared to HNO3 (26.7%) with the total cost of operation using HNO3 was double compared to chlorine extraction. The economic feasibility of HNO3 can be improved using various progress in the pre-treatment process, chemical recycling and cellulose recovery process since adopting it is crucial for environmental sustainability.


Asunto(s)
Celulosa/química , Oryza/metabolismo , Celulosa/metabolismo , Cristalización , Hidrólisis , Ácido Nítrico/química , Análisis de Componente Principal , Semillas/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura
12.
Food Chem ; 352: 129364, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33657482

RESUMEN

Rice is contaminated with pesticides applied in pre and post-harvest. These contaminations could be reduced through household operations like washing and cooking. Therefore, in the present research, a pre-soaking rice cooking method was used to reduce pesticides residues. Response Surface Methodology with Central Composite Design was applied to minimize pesticides concentration by choosing the best soaking time and water:rice grain relation before cooking. A quadratic polynomial equation was obtained. Desirability function approach gave the optimal cooking conditions as 14 h soaking time and water:rice grain relation of 3. This process allowed a pesticide elimination of 100.0%, 93.5%, 98.4%, 98.5%, 99.0%, and 95.0%, of azoxystrobin, cyproconazole, deltamethrin, epoxiconazole, kresoxim-methyl and penconazole, respectively.


Asunto(s)
Culinaria/métodos , Oryza/química , Residuos de Plaguicidas/análisis , Contaminación de Alimentos/análisis , Factores de Tiempo , Agua/química
13.
Molecules ; 26(4)2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33671806

RESUMEN

The metabolism of brassinosteroid leads to structural modifications in the ring skeleton or the side alkyl chain. The esterification and glycosylation at C-3 are the most common metabolic pathways, and it has been suggested that conjugate brassinosteroids are less active or inactive. In this way, plants regulate the content of active brassinosteroids. In this work, the synthesis of brassinosteroid 24-norcholane type analogs conjugated at C-3 with benzoate groups, carrying electron donor and electron attractant substituents on the aromatic ring, is described. Additionally, their growth-promoting activities were evaluated using the Rice Lamina Inclination Test (RLIT) and compared with that exhibited by brassinolide (used as positive control) and non-conjugated analogs. The results indicate that at the lowest tested concentrations (10-8-10-7 M), all analogs conjugated at C-3 exhibit similar or higher activities than brassinolide, and the diasteroisomers with S configuration at C-22 are the more active ones. Increasing concentration (10-6 M) reduces the biological activities of analogs as compared to brassinolide.


Asunto(s)
Benzoatos/química , Brasinoesteroides/síntesis química , Oryza/efectos de los fármacos , Reguladores del Crecimiento de las Plantas/síntesis química , Benzoatos/farmacología , Brasinoesteroides/química , Brasinoesteroides/farmacología , Relación Dosis-Respuesta a Droga , Conformación Molecular , Oryza/metabolismo , Reguladores del Crecimiento de las Plantas/química , Reguladores del Crecimiento de las Plantas/farmacología , Estereoisomerismo
14.
Food Chem ; 352: 129402, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690074

RESUMEN

A non-thermal processing method was developed to promote preservation of brown rice using dielectric barrier discharge cold plasma (DBD-CP). Physicochemical properties including free fatty acid (FFA) content, surface color change, volatile organic components (VOCs) and flavor fingerprints were evaluated in brown rice submitted to DBD-CP. FFA levels were 25.2% lower in treated samples compared to the control, and a more stable surface color was obtained at the end of the storage period. A total of 35 major VOCs could be detected in treated samples, and reduced levels of hexanal can be used as an indicator of DBD-CP treatment in brown rice during storage. Moreover, the flavor fingerprints in DBD-CP treated groups can be successfully distinguished through headspace gas chromatography ion mobility spectrometry. Collectively, application of DBD-CP treatment could be utilized as a feasible approach to promote stabilization of brown rice and preserve flavor during storage.


Asunto(s)
Frío , Oryza/química , Gases em Plasma/química , Gusto , Impedancia Eléctrica , Compuestos Orgánicos Volátiles/análisis
15.
Ecotoxicol Environ Saf ; 214: 112119, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714137

RESUMEN

Rice cultivation under cadmium (Cd) contaminated soil often results in reduced growth with excess grain Cd concentrations. A pot experiment was conducted to assess the potential of ultrasonic seed treatment to alleviate Cd stress in rice. Seeds of two aromatic rice cultivars i.e., Xiangyaxiangzhan and Meixiangzhan 2 and two non-aromatic rice cultivars i.e., Huahang 31 and Guangyan 1 were exposed to ultrasonic waves for 1.5 min in 20-40 KHz mixing frequency. The experimental treatments were comprised of untreated seeds (U0) and ultrasonic treated seeds (U1) transplanted in un-contaminated soil (H0) and Cd-contaminated soil (H1). Results revealed that Cd contents and Cd accumulation in grain in U1 were 33.33-42.31% and 12.86-57.58% lower than U0 for fragrant rice cultivars under H1. Meanwhile, biomass production was higher in U1 than U0 under H0 and better yield was assessed in U1 for all cultivars under H1. The activity of peroxidase (POD) in flag leaves was increased by 8.28-115.65% for all cultivars while malondialdehyde (MDA) contents were significantly decreased in U1 compared with U0 under H0. Conclusively, ultrasonic treatment modulated Cd distribution and accumulation in different parts while improved physiological performance as well as yield and grain quality of rice under Cd contaminated conditions.


Asunto(s)
Cadmio/metabolismo , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Contaminantes del Suelo/metabolismo , Ondas Ultrasónicas , Grano Comestible/crecimiento & desarrollo , Grano Comestible/metabolismo , Malondialdehído/metabolismo , Peroxidasas/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Semillas/crecimiento & desarrollo
16.
Environ Pollut ; 276: 116696, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33744496

RESUMEN

It is a common practice to maintain soil fertility based on the paddy-upland rotation with green manure in the subtropical region of China. However, rare studies are known about greenhouse gas (GHG) emissions from the paddy-upland rotation with green manure incorporation. Therefore, we conducted a field experiment of two years to compared with the effect of two kinds of green manure (CV: Chinese milk vetch and OR: Oilseed rape), and two kinds of cropping system (DR: double rice system and PR: paddy-upland rotation) on greenhouse gases emissions. We have found that the annual accumulation of CH4 of Chinese milk vetch-rice-sweet potato || soybean was significantly reduced by 32.95%∼63.22% compared with other treatments, mainly because Chinese milk vetch reduced the abundance of methanogens by reducing soil C/N ratio. Meanwhile increasing soil permeability resulting from paddy-upland rotation also reduced soil CH4 emission. However, The annual accumulation of N2O of Chinese milk vetch-rice-sweet potato || soybean was increased by 17.39%∼870.11% compared with other treatments, mainly attributed to paddy-upland rotation decreased soil pH and nosZ abundance and increased nirK and nirS, thus enhancing N2O emission, meanwhile the Chinese milk vetch incorporation and its interaction with the paddy-upland rotation has greatly enhanced the contents of NO3--N and abundance of ammonia-oxidizing archaea (AOA). The area-scaled global warming potential (GWP) and the biomass-scaled greenhouse gas emissions intensity (GHGI) of Chinese milk vetch-rice-sweet potato || soybean was reduced by 19.01%∼50.69% and 5.38%∼35.77% respectively. Thereby, the Chinese milk vetch-rice-sweet potato || soybean cropping system was suitable for agricultural sustainable development.


Asunto(s)
Astrágalo (Planta) , Gases de Efecto Invernadero , Oryza , Agricultura , China , Calentamiento Global , Metano/análisis , Óxido Nitroso/análisis , Rotación , Suelo
17.
Environ Sci Pollut Res Int ; 28(14): 18284-18293, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33665692

RESUMEN

The objective of this study was to check the potential of crude xylano-pectinolytic enzymes in bleaching of rice straw pulp, in order to reduce the toxic waste load for managing the environmental pollution. The xylano-pectinolytic enzymatic bleaching step for delignification was found to be most effective at pulp consistency 1:10 g/ml, xylanase:pectinase dose of 9:4 IU/ml, pH 8.5 and treatment time 180 min at temperature of 55 °C, and resulted in lowering of kappa number of the rice straw pulp by 15.29%. In subsequent bleaching stages, this enzymatic pre-bleaching treatment also resulted in 30% reduction of active chlorine dioxide dose without any loss of optical properties. Significant improvement in various physical properties of the enzymes treated pulp, tear index (15.43%), breaking length (11.11%), double fold number (25.92%), burst index (9.88%) and viscosity (13.63%), and Gurley porosity (39.86%) was also noticed. This approach resulted in reduction of BOD and COD values by 21.07% and 26.57%, respectively. This is the first study on the use of crude xylano-pectinolytic enzymes for bio-bleaching of rice straw pulp.


Asunto(s)
Oryza , Papel , Poligalacturonasa , Compuestos de Sodio , Temperatura
18.
Bioresour Technol ; 329: 124902, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33657500

RESUMEN

The purpose of this study is to explore the action characteristics of metabolic regulators like adenosine tri-phosphate (ATP) and malonic acid (MA) during rice straw (RS) and fruit and vegetable waste (FVW) composting. Results showed that due to the easy degradation difference, ATP and MA reduced CO2 emission in RS and FVW, respectively. Moreover, adding ATP and MA increased humic acids (HA) content in FVW more significantly (p < 0.05), especially for ATP. However, adding MA accelerated organic matter degradation during RS composting, which was basically consistent with CO2 emission, but it was not effective in promoting HA formation. Furthermore, the microbial community was reshaped by adding ATP and MA. Eventually, structural equation model further confirmed that adding metabolic regulators enhanced the biotic and abiotic pathways of HA formation, and the promotion effect of adding ATP was more obvious. The study has great practical significance for the dispose of agricultural waste.


Asunto(s)
Compostaje , Oryza , Carbono , Sustancias Húmicas/análisis , Suelo
19.
Nat Commun ; 12(1): 1944, 2021 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-33782402

RESUMEN

CRISPR-Cas12a is a promising genome editing system for targeting AT-rich genomic regions. Comprehensive genome engineering requires simultaneous targeting of multiple genes at defined locations. Here, to expand the targeting scope of Cas12a, we screen nine Cas12a orthologs that have not been demonstrated in plants, and identify six, ErCas12a, Lb5Cas12a, BsCas12a, Mb2Cas12a, TsCas12a and MbCas12a, that possess high editing activity in rice. Among them, Mb2Cas12a stands out with high editing efficiency and tolerance to low temperature. An engineered Mb2Cas12a-RVRR variant enables editing with more relaxed PAM requirements in rice, yielding two times higher genome coverage than the wild type SpCas9. To enable large-scale genome engineering, we compare 12 multiplexed Cas12a systems and identify a potent system that exhibits nearly 100% biallelic editing efficiency with the ability to target as many as 16 sites in rice. This is the highest level of multiplex edits in plants to date using Cas12a. Two compact single transcript unit CRISPR-Cas12a interference systems are also developed for multi-gene repression in rice and Arabidopsis. This study greatly expands the targeting scope of Cas12a for crop genome engineering.


Asunto(s)
Arabidopsis/genética , Proteínas Bacterianas/genética , Proteínas Asociadas a CRISPR/genética , Sistemas CRISPR-Cas , Endodesoxirribonucleasas/genética , Edición Génica/métodos , Ingeniería Genética/métodos , Genoma de Planta , Oryza/genética , Agrobacterium tumefaciens , Alelos , Arabidopsis/metabolismo , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Proteína 9 Asociada a CRISPR/genética , Proteína 9 Asociada a CRISPR/metabolismo , Proteínas Asociadas a CRISPR/metabolismo , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Productos Agrícolas , Endodesoxirribonucleasas/metabolismo , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Oryza/metabolismo , Plantas Modificadas Genéticamente , ARN Guia/genética , ARN Guia/metabolismo , Alineación de Secuencia
20.
J Environ Sci (China) ; 103: 336-346, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33743915

RESUMEN

Selenium nanoparticles (Se NPs) are less toxic and more biocompatible than selenite or selenate. However, studies involving spraying with Se NPs for reducing accumulation of cadmium (Cd) and lead (Pb) in rice grains have been rarely reported as yet. Herein, indica rice seedlings cultivated in Cd+Pb-spiked paddy soils (denoted as positive control) were sprayed with Se NPs sols for four times from tillering to booting stage. Compared to positive control, 50-100 µmol/L Se NPs downregulated Cd transporters-related genes such as OsLCT1, OsHMA2 and OsCCX2 in leaves and OsLCT1, OsPCR1 and OsCCX2 genes in node I at filling stage. Meanwhile, Se-binding protein 1 was distinctly elevated, involving the repression of Cd and Pb transportation to rice grains. Se NPs also differentially improved RuBP carboxylase and chlorophylls especially some key genes and proteins involving photosynthetic system. Besides, 25-50 µmol/L Se NPs diminished reactive oxygen species overproduction from NADPH oxidases whereas boosted glutathione peroxidase, reducing protein carbonylation in rice seedlings. However, the antioxidant isozymes and oxidatively modified proteins were slightly rebounded at 100 µmol/L. Se contents were noticeably elevated and confirmed to exist as selenomethionine in the rice grains following all the treatments by Se NPs. Thus, the optimal dosage of Se NPs for foliar application is 50 µmol/L, which significantly decreased Cd accumulation, improved photosynthesis and Se enrichment whereas caused no distinct reduction of Pb in the grains. Thus, an appropriate dosage of Se NPs can be conducted to decrease Cd accumulation, improve photosynthesis, and organic Se contents in rice grains.


Asunto(s)
Oryza , Selenio , Contaminantes del Suelo , Cadmio/análisis , Plomo , Fotosíntesis , Suelo , Contaminantes del Suelo/análisis
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