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Straw return is an effective management practice. It not only utilizes agricultural waste but also introduces dissolved organic matter (DOM) into the soil. Selenium (Se) is an essential trace element in the human diet and contributes to the popularity of Se-enriched agricultural products in the Chinese market. Moreover, there are still some Se-enriched agricultural products that have yet to be utilized. This study investigated whether Se addition in soil caused component changes in the DOM extracted from rape straw. DOM extracted from rape straw grown in soil with four Se levels (0, 0.1, 0.5 and 1.0 mg Se kg−1 soil) was characterized by UV-Visible spectroscopy, fluorescence spectroscopy and FTIR spectroscopy. The UV-visible spectra revealed that 0.1 mg Se kg−1 soil reduced the molecular weight of DOM and caused the presence of more irreplaceable aromatic structures in the substituent groups of the DOM, while 0.5 and 1.0 mg Se kg−1 soil only reduced the DOM molecular weight. Fluorescence spectroscopy indicated that Se improved the humification degree but reduced the aromaticity of DOM. FTIR spectra proved that Se altered the contents of carboxylic acids, amino acids, alcohols and aromatic heterocycles in DOM, which were maximized in the 0.5 and 1.0 mg Se kg−1 treatment groups. We concluded that Se application could change the composition of DOM extracted from rape straw, potentially impacting the nutrient bioavailability in soil. This study provides basic data on Se-enriched rape straw utilization for eco-agriculture.

Water deficit is a key factor to induce flowering in many woody plants, but reports on the molecular mechanisms of floral induction and flowering by water deficit are scarce. Here, we analyzed the morphology, cytology, and different hormone levels of lemon buds during floral inductive water deficits. Higher levels of ABA were observed, and the initiation of floral bud differentiation was examined by paraffin sections analysis. A total of 1638 differentially expressed genes (DEGs) were identified by RNA sequencing. DEGs were related to flowering, hormone biosynthesis, or metabolism. The expression of some DEGs was associated with floral induction by real-time PCR analysis. However, some DEGs may not have anything to do with flowering induction/flower development; they may be involved in general stress/drought response. Four genes from the phosphatidylethanolamine-binding protein family were further investigated. Ectopic expression of these genes in Arabidopsis changed the flowering time of transgenic plants. Furthermore, the 5′ flanking region of these genes was also isolated and sequence analysis revealed the presence of several putative cis-regulatory elements, including basic elements and hormone regulation elements. The spatial and temporal expression patterns of these promoters were investigated under water deficit treatment. Based on these findings, we propose a model for citrus flowering under water deficit conditions, which will enable us to further understand the molecular mechanism of water deficit-regulated flowering in citrus.Highlight:Based on gene activity during floral inductive water deficits identified by RNA sequencing and genes associated with lemon floral transition, a model for citrus flowering under water deficit conditions is proposed.

Nitrogen management is the major challenge due to narrow understanding of yield and N uptake relationship on salt-affected soils. To address this problem, a lysimeter experiment for rice and wheat was conducted on salt-affected soil with two lower (15 and 30 %) and three higher N rates (15, 30 and 45 %) with 50 and 100 % SGR. NO3 - leaching was greater with higher N rates (up to 188 mg Leachate-1) in rice as compared to wheat. After the harvesting of rice and wheat, maximum decrease in soil pHs (7.75 %), ECe (41.50 %), SAR (63.64 %) was with N130 G100 which indicated that applied gypsum 100 % SGR with higher N rate ameliorated the soil more efficiently as compared to 50 % SGR. The highest yields recorded with N130 + 100 % SGR. The highest NUE (15.88 g/g) was with treatment G100 N130 in rice but in wheat (NUE, 44.76 g/g) G100 N70 proved to be the best. It was concluded that G100 N130 proved to be the best and reduced the environmental risks. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate citrus tissue's response to varying applications of Fe-EDDHA, zinc (Zn) and manganese (Mn) combinations and the resulting effects on citrus fruit yield and quality in calcareous soil. A field experiment was conducted for three years with satsuma mandarin trees planted in calcareous soil. Four treatments were conducted: (i) control; (ii) soil Fe application; (iii) soil Fe+Zn application; and (iv) soil Fe+Zn+Mn application. Soil available Fe and Zn concentrations were raised through the application of Fe-EDDHA and Zn, whereas the soil available Mn concentration was not increased through the application of Mn. Applying Fe-EDDHA raised the leaf active Fe content significantly without influencing the leaf and fruit Fe concentrations. The Zn concentrations in leaf and fruit decreased when Fe-EDDHA was applied exclusively, but increased when Fe+Zn and Fe+Zn+Mn were applied in the third year. There was no significant difference in leaf and fruit Mn concentrations among all treatments between 2010 and 2012. Soil Fe, Fe+Zn and Fe+Zn+Mn application increased fruit number by 23.5%, 26.7% and 24.9%, respectively, and soil Fe+Zn application increased the yield in 2012. Fruit TSS, TA and Vc content were higher through the application of Fe+Zn and Fe+Zn+Mn in 2012. The results revealed that Fe and Zn play different roles that affect fruit yield and quality in calcareous soil. The citrus yield was mainly affected by Fe, whereas fruit quality was improved by Zn. The application of Fe-EDDHA alone could induce Zn deficiency, so the co-application of Fe-EDDHA and Zn fertilizer was useful for obtaining higher yield and quality in satsuma mandarin in calcareous soil. [ABSTRACT FROM AUTHOR]

Background and Aim: MicroRNAs (miRNAs) are non-coding RNA molecules of 21–24 nt that regulate the expression of target genes in a post-transcriptional manner. Evidence indicates that miRNAs play essential roles in embryogenesis, cell differentiation, and pathogenesis of human diseases including cancer. Methods: We analyzed the miRNA expression profiles in 10 pairs of hepatocellular carcinoma (HCC) and adjacent non-tumorous tissue (NT) from 10 non-viral hepatitis patients, using a mammalian miRNA microarray containing whole human mature and precursor miRNA sequences. Results: A total of 15 miRNAs exhibited higher expression in the HCC samples than that in the NT samples, and one miRNA demonstrated lower expression in the HCC samples than in the NT samples. A total of 18 miRNAs identified valid expression only in HCC samples, with six only in NT samples. The chip results were confirmed by Northern blot analysis. Conclusion: Our study may help clarify the molecular mechanisms involved in the pathogenesis of HCC, and miRNAs potentially serve as a novel diagnostic tool of HCC. [ABSTRACT FROM AUTHOR]