Search

In this paper, hyperaccumulator straw (Solanum nigrum L., Amaranthus chinense L., and Siegesbeckia orientalis L.) and phosphate rock powder were selected as materials, a pot experiment was used to study the effects of three compounding modifiers on the growth, nutritional quality and cadmium (Cd) content of Chinese cabbage. The results showed that: (1) The combination of Siegesbeckia orientalis + phosphate rock powder can significantly promote the growth of Chinese cabbage, while Solanum nigrum + phosphate rock powder and Amaranthus chinense + phosphate rock powder have no effect on the growth of Chinese cabbage. (2) The combination of Solanum nigrum and phosphate rock powder increased the content of soluble sugar, soluble protein and VC in shoots of Chinese cabbage by 64.33%, 16.27% and 2.2%, respectively, and the nitrite content decreased by 34.58%, which improved the quality of Chinese cabbage. (3) Different compounding modifiers can significantly reduce the Cd content in shoots of Chinese cabbage, and the reduction of Solanum nigrum + phosphate rock powder is the largest, reaching 61.29%. In conclusion, all three modifiers can improve the nutritional quality and reduce the Cd content in the shoots of Chinese cabbage, and Solanum nigrum + phosphate rock powder has the best effect.

Soil culture experiments were carried out to study the effects of the mixture of cadmium (Cd) hyperaccumulator straw (Solanum nigrum L., Amaranthus chinense L., and Siegesbeckia orientalis L.) and phosphate rock on soil pH, available Cd content and soil nutrients in Cd polluted soil. The results showed that: (1) The soil pH was increased to a certain extent by three kinds of compound materials. (2) The contents of available potassium (AK) and available phosphorus (AP) in soil were increased to a certain extent by the three compounding materials, but there was no significant effect on total nitrogen (TN). And 2% phosphate rock powder and 1% Amaranthus chinense L. had the greatest increase in AP, reaching 49.28%, and 2% phosphate rock powder and 1% Siegesbeckia orientalis L. had the greatest increase in AK, reaching 136.23%. (3) The available Cd content in soil was reduced by three kinds of compound materials. The decrease of available Cd was the greatest in 2% phosphate rock powder and 1% Solanum nigrum L. straw mixed, which was 12.71%. In summary, the combination of Cd hyperaccumulator straw and phosphate rock powder can effectively passivate Cd in soil and improve soil nutrient content, and 2% phosphate rock powder and 1% Solanum nigrum L. straw are the best.

Soil culture experiments were carried out to study the effects of the mixture of Amaranthus chinense L. straw and phosphate rock on soil pH, available phosphorus (AP), available potassium (AK) and DTPA-Cd content in Cd polluted soil. The results showed that: (1) 2% phosphate rock powder combined with 1%, 2%, 3% of Amaranthus chinense L. straw can significantly increase soil pH, AP and AK content. Compared with CK, pH was increased by 0.42~0.56, 0.53~0.70 and 0.47~0.73 units, respectively, and AP was increased by 19.03%~32.62%, 14.91%~43.63% and 18.88%~58.01%, respectively, and AK was increased by 201.46%~234.66%, 210.5%~266.56% and 184.07%~224.98%, respectively. (2) The DTPA-Cd content in soil decreased significantly after adding three different ratios of compound materials, which were 1.75%~9.01%, 2.86%~10.02% and 0.98%~8.7% lower than CK, respectively. In summary, the mixture of 1% Amaranthus chinense L. straw and 2% phosphate rock powder had the best passivation effect on Cd.

The perturbation induced by a wall-mounted transverse circular cylinder element (TCCE) to a turbulent boundary layer (TBL) is studied using particle image velocimetry (PIV). Measurements are also performed on a smooth wall, which is used as baseline for comparison. The modification of the TBL caused by the sudden perturbation, in a statistical sense, is quantified by comparing the distributions of mean velocity, Reynolds stresses and shape factor in the two geometrical configurations. The impact of the TCCE on the TBL is found to extend more than 9 boundary-layer thickness downstream. Combining the side- and top-view PIV data indicates that the packet-like structures are stretched along the streamwise direction within a flat inclination angle when climbing over the TCCE, and retain their large spatial scales. The separated vortices induced downstream of the TCCE, are quickly lifted up to form the hairpin vortices within strong swirling strength. Then, the robust hairpin packets are generated downstream through the auto-generation scenario, which occupies the low-speed regions beneath the residual hairpin packet’s heads and impairs the process that the low-momentum fluids feed the concentrated vorticity into the residual hairpin heads. Meanwhile, the streamwise-stretched low-momentum regions (LMRs) are redeveloped in the inner layer underneath the new-generated hairpin packets. Further downstream, even though the residual hairpin packets’ heads are merged by the robust hairpin packets, they are not completely dissipated, and still interact with the new-generated hairpin packets in the outer layer to the end of the field of view. [ABSTRACT FROM AUTHOR]

Phytosterols are membrane components or precursors for brassinosteroid ( BR) biosynthesis. As they cannot be transported long distances, their homeostasis is tightly controlled through their biosynthesis and metabolism. However, it is unknown whether micro RNAs are involved in their homeostatic regulation., Rice ( Oryza sativa) plants transformed with microRNA osa-miR1848 and its target, the obtusifoliol 14α-demethylase gene, Os CYP51G3, were used to investigate the role of osa-miR1848 in the regulation of phytosterol biosynthesis., osa-miR1848 directs Os CYP51G3 mRNA cleavage to regulate phytosterol and BR biosynthesis in rice. The role of Os CYP51G3 as one of the osa-miR1848 targets is supported by the opposite expression patterns of osa-miR1848 and Os CYP51G3 in transgenic rice plants, and by the identification of Os CYP51G3 mRNA cleavage sites. Increased osa-miR1848 and decreased Os CYP51G3 expression reduced phytosterol and BR concentrations, and caused typical phenotypic changes related to phytosterol and BR deficiency, including dwarf plants, erect leaves, semi-sterile pollen grains, and shorter cells. Circadian expression of osa-miR1848 regulated the diurnal abundance of Os CYP51G3 transcript in developing organs, and the response of Os CYP51G3 to salt stress., We propose that osa-miR1848 regulates Os CYP51G3 expression posttranscriptionally, and mediates phytosterol and BR biosynthesis. osa-miR1848 and OsCYP51G3 might have potential applications in rice breeding to modulate leaf angle, and the size and quality of seeds. [ABSTRACT FROM AUTHOR]

Introduction: Soil quality plays an irreplaceable role in plant growth for restored grassland. However, few studies investigate the comprehensive effects considering soil and vegetation properties during the restoration of desertified grassland, which restrict the virtuous circle of restored grassland ecosystem., Methods: By setting three restoration patterns of enclosure plus grass (EG), enclosure intercropping shrub-grass (ESG), and enclosure plus sand-barrier and shrub-grass (ESSG) with three different restoration years (≤5, 7-9, and ≥15 years), we selected 28 physicochemical and microbial indicators, and constructed a minimum data set (MDS) to analyze the influences of restoration measurements on soil quality and ecological benefits in alpine desertified grassland., Results: The results showed that the MDS comprised seven soil quality indicators: silt, total nitrogen (TN), carbon-nitrogen ratio (C/N), total potassium (TK), microbial biomass carbon (MBC), microbial biomass phosphorus (MBP), and fungi. Soil quality index (SQI) and ecological restoration effect index (EREI) in restored grasslands significantly increased by 144.83-561.24% and 87.21-422.12%, respectively, compared with unrestored grassland, and their positive effects increased with extending restoration years. The increasing effects of SQI and EREI were the highest in ESSG, followed by EG and ESG. The increasing rate of SQI began to decrease after 5 years in EG and ESG, while it decreased after 7-9 years in ESSG, and that of EREI in EG was lower than ESSG in each restoration year. Our work revealed that ESSG was the optimum restoration pattern for desertified grassland, and anthropogenic monitoring and management measurements such as applying organic fertilization and mowing return reasonably should be carried out at the beginning of 5 years in EG and ESG as well as 7 years in ESSG to maintain sustainable ecological benefits., Discussion: The study highlights that soil quality, including microbial properties, is a key factor to evaluate the restoration effects of desertified grassland., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Hu, Lang, Pu, Zhang, Li, Xu, Jia, Wang, Yuan and Li.)

Phytosterols are membrane components or precursors for brassinosteroid (BR) biosynthesis. As they cannot be transported long distances, their homeostasis is tightly controlled through their biosynthesis and metabolism. However, it is unknown whether microRNAs are involved in their homeostatic regulation. Rice (Oryza sativa) plants transformed with microRNA osa-miR1848 and its target, the obtusifoliol 14α-demethylase gene, OsCYP51G3, were used to investigate the role of osa-miR1848 in the regulation of phytosterol biosynthesis. osa-miR1848 directs OsCYP51G3 mRNA cleavage to regulate phytosterol and BR biosynthesis in rice. The role of OsCYP51G3 as one of the osa-miR1848 targets is supported by the opposite expression patterns of osa-miR1848 and OsCYP51G3 in transgenic rice plants, and by the identification of OsCYP51G3 mRNA cleavage sites. Increased osa-miR1848 and decreased OsCYP51G3 expression reduced phytosterol and BR concentrations, and caused typical phenotypic changes related to phytosterol and BR deficiency, including dwarf plants, erect leaves, semi-sterile pollen grains, and shorter cells. Circadian expression of osa-miR1848 regulated the diurnal abundance of OsCYP51G3 transcript in developing organs, and the response of OsCYP51G3 to salt stress. We propose that osa-miR1848 regulates OsCYP51G3 expression posttranscriptionally, and mediates phytosterol and BR biosynthesis. osa-miR1848 and OsCYP51G3 might have potential applications in rice breeding to modulate leaf angle, and the size and quality of seeds., (© 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.)