Effects of crop straw biochars on aluminum species in soil solution as related with the growth and yield of canola (Brassica napus L.) in an acidic Ultisol under field condition.

The toxicity of aluminum (Al) to plants in acidic soils depends on the Al species in soil solution. The effects of crop straw biochars on Al species in the soil solution, and canola growth and yield were investigated in this study. In a long-term field experiment, there were four treatments, which were a control, rice straw biochar (RSB), canola straw biochar (CSB), and peanut straw biochar (PSB). The soil solution was collected in situ, the Al species were identified, and the relationships between the concentration of phytotoxic Al and canola growth and yield were evaluated. The results showed that applying the three biochars resulted in significant decreases in the concentrations of total Al, monomeric Al, and monomeric inorganic Al (P < 0.05). The Al3+, Al-OH, and Al-SO4 proportions of the total Al also decreased. The abilities of the different biochars to reduce dissolved Al followed the order PSB > CSB > RSB, which was consistent with the alkalinity of these biochars. Application of the biochars significantly decreased the concentration of phytotoxic Al (Al3+ + Al-OH), which improved canola growth and increased the canola seed and straw yields. Plant height, leaf number per plant, area per leaf, chlorophyll content, and canola yield were negatively correlated with the Al3+ + Al-OH concentrations. Therefore, the results showed that crop straw biochars can be used to ameliorate soil acidity and alleviate Al toxicity in acidic soils, and that peanut straw biochar is the best amendment for acidic soils.

Periphyton has the potential to increase phosphorus use efficiency in paddy fields.

The phosphorus (P) supply is mismatched with rice demand in the early and late stages of rice growth, which primarily results in low P use efficiency and high environmental risk. In recent years, the use of the natural periphyton in nutrient regulation in paddy fields has attracted much research interest. However, a mechanistic understanding of the action of periphyton on P biogeochemical cycling during the pivotal stages of rice growth has received little attention. In this study, the influence of periphyton proliferation on the soil surface and its consequential decomposition on P migration and bioavailability were investigated in two paddy soils using two microcosm experiments. The results showed that periphyton rapidly accumulated fertilizer P when it proliferated on the soil surface under favorable light condition, which led to more fertilizer P being stored on the soil surface and less P being fixed by soil particles or transported via runoff into the water bodies. The decomposition of periphyton under unfavorable light condition not only increased soil soluble reactive P, but also increased the amount of easily available P species, such as labile P, AlP, FeP, and mobilized OP. Thus, periphyton colonizing the soil surface in the early stage of rice growth could act as a P sink and decrease the P environmental risk, and its decomposition in the late stage of rice growth could act as a P source and activator. Phosphorus bioavailability regulated by periphyton could be synchronous with rice needs. Thus, periphyton has the potential to increase P use efficiency in paddy fields.

Mechanisms of enhanced inorganic phosphorus accumulation by periphyton in paddy fields as affected by calcium and ferrous ions.

The effect of periphyton propagation in paddy fields on phosphorus biogeochemical cycling has received little attention. In this phytotron study, inorganic phosphorus (Pi) accumulation by periphyton was investigated for varying inputs of calcium [Ca(II)] or ferrous­iron [Fe(II)], and lighting conditions. Results indicated that additions of Ca(II) or Fe(II) enhanced abiotic accumulation of Pi by up to 16 times, and decreased solution Pi concentration by up to 50%, especially under light condition. The enhanced Pi accumulation into periphyton intensified with increasing Pi concentration, and Pi accumulation showed a positive linear relationship with Ca or Fe accumulation. Abiotic accumulation of Pi induced by Ca(II) was mainly through Ca-phosphate precipitation, and co-precipitation of P with carbonates at pH>8. Accumulation with added Fe(II) was mainly considered to be through Fe(III) phosphate precipitation coupled with adsorption of Pi by ferric hydroxides. Moreover, Fe(II) was more effective than Ca(II) in promoting abiotic accumulation of Pi by periphyton. Our results indicate the potential for controlling environmental factors to enhance the role of periphyton in biogeochemical cycling and P-use efficiency in paddy rice fields and to reduce P discharged to neighboring water bodies.

Variation of rhizosphere bacterial community in watermelon continuous mono-cropping soil by long-term application of a novel bioorganic fertilizer.

The application method for a novel bioorganic fertilizer (BIO) was developed to improve its biocontrol efficacy of Fusarium wilt (Ling et al. 2010). However, its efficacy on controlling Fusarium wilt and the variations of microbial community after long-term application for watermelon production had not been elucidated. To clarify, a 4-years pot experiment of mono-cropping watermelon was conducted. The results revealed that though the disease incidences were increased in all treatments with the increase of continuous cropping years, the treatment of BIO application both in nursery and pot soil always maintained the lowest disease incidence. The real-time PCR results showed that the population of Paenibacillus polymyxa was decreased with continuous cropping years, but in all seasons, the treatment with BIO application both in nursery and pot soil had a highest population of P. polymyxa than the other treatments. On the other hand, the abundance of the pathogen FON was increased with the increase of continuous cropping years and the lowest rate of increase was found by BIO application in both nursery and pot soil. DGGE patterns showed that the bacterial diversity was weakened after mono-cropping of watermelon for 4 years, but the consecutive applications of BIO at nursery and transplanting stage resulted in the minimal change of bacterial diversity. More detailed differences on bacterial diversity between control and double application of BIO treatment after 4-years monoculture were analyzed by 454 pyrosequencing, which showed the dominant phyla found in both samples were Firmicutes, Proteobacteria and Actinobacteria, and the consecutive applications of BIO recruited more beneficial bacteria than control, such as Bacillus, Paenibacillus, Haliangium, Streptomyces. Overall, these results, to a certain extent, approved that the consecutive applications of BIO at nursery and transplanting stage could effectively suppress watermelon Fusarium wilt by regulating the rhizosphere bacterial diversity. These results could give some clues that how to regulate the soil microbial community to an appropriate level which can keep the plant healthy and thus control the soil-borne diseases.

[Simultaneous determination of six ingredients in Huoxiang Zhengqi oral liquid by UPLC].

OBJECTIVE: To develop a UPLC method for the simultaneous determination of liquiritin, narirutin, hesperidin, ammonium glycyrrhetate, honokiol and magnolol in Huoxiang Zhengqi oral liquid. METHOD: A Zorbax Eclipse C18 column was used with the mobile phase of acetonitrile and 0. 05% phosphate acid by gradient elution at the detection wavelength of 220 nm. The flow rate was 0.42 mL x min(-1) and the column temperature was 30 degrees C. RESULT: The calibration curves were linear in the ranges of 0.001 7-0.034, 0.003 4-0.068, 0.006 4-0.128, 0.012 8-0.256, 0.003 2-0.064, 0.006 4-0.128 microg, respectively. The average recoveries were 103.3%, 98.39%, 98.29%, 102.1%, 98.45%, 102.2% with RSDs of 2.1%,1.0%, 0.50%, 2.3%, 0.9%, 2.0%, respectively. CONCLUSION: The UPLC method was simple, rapid and accurate, it could be used for quality control of Huoxiang Zhengqi oral liquid.

ICAT as a potential enhancer of monocytic differentiation: implications from the comparative proteome analysis of the HL60 cell line stimulated by all-trans retinoic acid and NSC67657.

A novel sterol mesylate compound (NSC67657) was recently identified and reported by National Cancer Institute that could efficiently induce the differentiation of HL60 cells into monocytes in vitro and in vivo. The expression of many proteins would have been changed during the differentiation process, and some proteins may have played key roles in the differentiation of HL60 cell line induced by this drug. Therefore, we treated HL60 cells with NSC67657 and all-trans retinoic acid (ATRA) to identify the differentially expressed proteins and determine their functions in cellular differentiation. Of the 45 differentially expressed protein spots investigated, 24 were either elevated or decreased in both the monocytic and granulocytic differentiating HL60 cells, 8 showed significant changes only when induced by NSC67657, and 13 showed significant changes only when induced by ATRA. After verification by RT-PCR, Western blotting, and immunocytochemistry, only the protein ICAT was found to be elevated by NSC67657 treatment alone. Although the over-expression of ICAT is not sufficient to induce the differentiation of HL60 cells into monocytes, it did increase the proportion of CD14+ cells in cells pretreated with NSC67657. Successful application of multiple techniques including two-dimensional gel electrophoresis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, Western blotting, and eukaryotic electroporation revealed that proteomic and molecular biological analyses provide valuable tools in drug development research.