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Iron-sulfur (Fe-S) cluster assembly genes play important roles in plant growth and development. However, their biological function in fruit crops is still unknown, especially in strawberry. In this study, Fe depletion significantly inhibited the growth, photosynthesis, Fe accumulation level and the enzyme activity of Fe-S proteins of aconitase (ACO), nitrate reductase (NiR) and succinate dehydrogenase (SDH) in strawberry seedlings. In addition, 40 Fe-S cluster assembly genes were isolated from strawberry, which were significantly varied among different tissues/organs and were differentially responded to Fe depletion in different tissue parts. In total, 79% of the responsive genes were up-regulated in shoots, while 65% of the responsive genes were down-regulated in roots under Fe depletion. Moreover, the expression level of ISU1 was the highest in strawberry tissues, especially in young fruits, and over-expression of ISU1 gene in Arabidopsis significantly enhanced the Fe accumulation, leaf total chlorophyll, ACO and SDH activities in transgenic lines, and strengthened plant tolerance to Fe depletion. This study provides gene resources to elucidate the molecular mechanisms of Fe-S cluster assembly in strawberry, and lays a theoretical foundation to reveal Fe nutrition and metabolism in Rosaceae fruits. • Fe depletion inhibited the growth, photosynthesis, Fe content and activity of ACO, NiR and SDH in strawberry seedlings. • Forty Fe–S cluster assembly genes were isolated and identified in strawberry, which were differentially responded to Fe depletion. • Non-functional scaffolds are more likely to be lost in perennial plants, including strawberry. • Expression level of ISU1 was the highest in strawberry, and overexpression of ISU1 in Arabidopsis enhanced plant tolerance to Fe deficiency. [ABSTRACT FROM AUTHOR]

Iron (Fe) is required for the iron–sulphur (Fe–S) cluster biosynthesis, which occurs in chloroplasts, mitochondria and cytosol that needs dozens of genes. However, molecular mechanisms of Fe metabolism in fruit trees are largely rare, especially towards fruit development and ripening. In this work, we characterized ‘Xiahui8′ peach development, and analyzed expression profiles of 44 Fe–S cluster biosynthesis genes during different fruit development stages. The development of ‘Xiahui8′ peaches last for an average period of 130 days, followed by a rapid on-tree ripening during 7 days. Notably, the Fe accumulation in peach flesh was negatively correlated to fruit weight and volume, but positively correlated to flesh firmness. Quantitative Real-Time PCR (qRT-PCR) analysis showed that Fe–S cluster biosynthesis genes were differentially expressed during distinct fruit development stages. A majority of plastid SUF and mitochondrial ISC machinery genes were gradually enhanced along with fruit growth, and began to decrease since commercial harvest phase. The highest expression level of all cytosolic CIA machinery genes were appeared in early fruitlet formation stage, and gradually reduced until fruit ripening. Moreover, foliar spraying of amino acid-Fe compound fertilizer significantly enhanced the total soluble solid (TSS) content in peaches, accompanied by strengthened flesh firmness, Fe concentration, and succinate dehydrogenase (SDH) and aconitase (ACO) activities. Thirteen Fe–S cluster biosynthesis genes were responsive to fertilizer treatment, whose expression level were significantly induced, with the exception of HSCA2 that was reduced. Our findings provided molecular basis for Fe metabolism in peach fruit development, and revealed potential genes for further functional verification. [ABSTRACT FROM AUTHOR]

A cold-cathode penning ion gauge (PIG) source built with permanent magnet for the production of intense O- ion beam has been developed for the simultaneous acceleration of O- and O+ ion beams in a 1 MV RFQ accelerator. O- ion beam of intensity of 1.5 mA has been produced with this small PIG ion source. The effects of the source magnetic field, cathode material and extraction aperture on the production of the intense O- ion beam have been investigated and will be presented in this article. [Copyright &y& Elsevier]

Cytochrome P450 monooxygenases (CYP450s) play crucial roles in the regulation of plant growth and response to abiotic stress. However, their functions in woody trees are still largely unknown. Previously, we reported that expression of the rice cytochrome P450 monooxygenase gene OsCYP714D1 increased gibberellic acid (GA) accumulation and shoot growth in transgenic poplar. In this work, we demonstrate that expression of OsCYP714D1 improved the salt tolerance of transgenic poplar plants. Compared to wild type, plant height and K+ content were significantly higher, whereas plant growth inhibition and Na+ content were significantly lower, in transgenic plants grown under high salt stress condition. Transcriptomic analyses revealed that OsCYP714D1 expression up-regulated the expressions of GA biosynthesis, signaling and stress responsive genes in transgenic plants under both normal and high salt stress conditions. Further gene ontology (GO) analyses indicated that genes involved in plant hormone and ion metabolic activities were significantly enriched in transgenic plants. Our findings imply that OsCYP714D1 participated in the regulation of both shoot growth and salt resistance through regulating gibberellin and ion homeostasis in transgenic poplar, and it can be used as a candidate gene for the engineering of new tree varieties with improved biomass production and salt stress resistance. • Constitutive expression of OsCYP714D1 promoted growth and salt tolerance in transgenic poplar. • Expression of gibberellin synthesis and metabolism genes was affected in OsCYP714D1 transgenic poplar. • OsCYP714D1 transgenic poplar showed altered ion homeostasis and related gene expression. [ABSTRACT FROM AUTHOR]

Alternative splicing (AS) plays a crucial role in plant growth, development and response to various environmental changes. However, whether alternative splicing of MADS-box transcription factors contributes to the flower bud dormancy process in fruit trees still remains unknown. In this work, the AS profile of genes in the dormant flower buds of 'Dangshansu' pear tree were examined. A total number of 3661 alternatively spliced genes were identified, and three mRNA isoforms of the dormancy associated MADS box (DAM) gene, PpDAM1 , derived by alternative splicing, designated as PpDAM1.1 , PpDAM1.2 and PpDAM1.3 , were characterized. Bimolecular fluorescence complementation (BiFC) analysis indicated that AS of PpDAM1 didn't affect the nucleus localization and homo-/heterodimerization of PpDAM1.1, PpDAM1.2 and PpDAM1.3 proteins, but disturbed the translocation of PpDAM1.1/PpDAM1.1, PpDAM1.3/PpDAM1.3, PpDAM1.1/PpDAM1.3, and PpDAM1.2/PpDAM1.3 dimers to the nucleus. Constitutive expression of PpDAM1.2 , but not PpDAM1.1 and PpDAM1.3 , in Arabidopsis retarded the growth and development of transgenic plants. Further comparative expression analyses of PpDAM1.1 , PpDAM1.2 and PpDAM1.3 in the flower buds of 'Dangshansu' and a less dormant pear cultivar, 'Cuiguan', exhibited that the expression of all the three isoforms in 'Dangshansu' were significantly higher than in 'Cuiguan', especially PpDAM1.2 , which showed a predominantly higher expression than PpDAM1.1 and PpDAM1.3 in both cultivars. Our results suggest that alternative splicing of PpDAM1 could play a crucial role in pear flower bud dormancy process. • Three alternative spliced mRNA isoforms of PpDAM1 were detected in pear buds. • Constitutive expression of PpDAM1.2 retarded the growth and flowering in Arabidopsis. • PpDAM1.2 showed higher expression than PpDAM1.1/1.3 in different pear cultivars. [ABSTRACT FROM AUTHOR]

• Transcriptome sequencing of the branches of 'Bartlett' and 'Red Bartlett'. • Weighted gene coexpression network analysis (WGCNA) identified 495 differentially expressed genes positively associated with anthocyanin. • The expression levels of one UFGT and one GST were also upregulated in the pericarps of 'Red Bartlett' and 'Starkrimson' than in 'Bartlett' and 'Clapps Favourite'. The color of the peel is the most direct reflection of fruit quality, and is also an important factor in attracting consumers. The 'Red Bartlett' pear (Pyrus communis L.) is a red bud sport mutant variety of 'Bartlett' pear. It was found that the anthocyanin content in branches and pericarps of 'Red Bartlett' pears were significantly higher than that of 'Bartlett' pears. The present study aimed to clarify the underlying mechanisms of anthocyanin accumulation in 'Red Bartlett' using a transcriptome analysis. A weighted gene coexpression network analysis (WGCNA) identified 495 differentially expressed genes positively associated with anthocyanin. Additionally, 12 anthocyanin-related structural genes and 13 transcription factors, including WRKY, ERF, bHLH, ASIL2, and HSF, were identified through screening of 495 DEGs. The expression levels of one UFGT (Pbr014258.1) and one GST (Pbr012649.1) were also upregulated in the pericarps of 'Red Bartlett' and 'Starkrimson', more so than in 'Bartlett' and 'Clapps Favourite'. Overall, this study clarified that the red color mutation of 'Red Bartlett' was closely linked to increased anthocyanin biosynthesis and transport. This study provided an abundance of valuable information on anthocyanin biosynthesis for future breeding of red-skinned pears. [ABSTRACT FROM AUTHOR]

Manganese (Mn) toxicity in soil is a widely observed phenomenon, which seriously restricts growth, quality, and yield of various crops and fruits including apples. However, mechanisms underlying the regulation of polyamines (PAs) by brassinosteroids (BRs) to improve tolerance to Mn stress are still unclear. In this study, we investigated the effects of 2,4-epibrassinolide (EBL; a BR) on the expression of genes involved in BR signaling pathway, Mn accumulation, PAs-mediated responses (PA precursor levels, metabolic enzymes, and genes), and growth parameters in Mn-stressed Malus robusta Rehd. EBL application significantly modulated the expressions of genes related to BR signaling (MdBRI , MdBSK , etc.) and reduced Mn accumulation, along with improving the rate of increase in root length and plant height, relative water content, chlorophyll content, maximum photochemical efficiency of PSII (Fv/Fm), and actual photochemical efficiency (Φ PSII) and decreasing electrical conductivity. Furthermore, EBL application significantly reduced putrescine (Put) accumulation and increased spermine (Spm) content and (Spd + Spm)/Put ratio. EBL weakened ornithine (Orn) pathway, decreased ornithine decarboxylase (ODC) activity, and increased biosynthesis of Spm from Put via elevating the PA oxidase (PAO) activity and expression of MdSPDS , MdSPMS , and MdPAO. The trends for free, PS-conjugated, and PIS-bound PAs were similar to that of total PAs, except that no significant change was observed in free Spm, PS-conjugated Spd, and Spm, as well as PIS-bound Spd. This study revealed that BR-regulated PAs help in mitigating Mn toxicity and clarified the mechanisms of regulation of PAs by BRs in apple trees. • EBL application significantly activated the expressions of genes related to BR signaling. • Mn accumulation was significantly reduced after EBL application. • EBL application improved growth parameters and physiological indexes in M. robusta under Mn toxicity. • The strategy to overcome Mn stress was highly associated with the stimulation of PAs profile by BRs. • The mechanism of regulation of PAs by BRs against Mn stress was provided. [ABSTRACT FROM AUTHOR]

Abstract: A protein microarray containing 144 known or putative virulence-related proteins of Yersinia pestis was used to evaluate the antibody responses of plague patients. Forty-two proteins were found to be expressed in vivo and antibodies against 14 of them were detected in all patients analyzed, providing potential candidates for novel protective antigens and novel serodiagnostic markers in Y. pestis. Moreover, the lack of antibody to LcrV in the five patients in Focus F might be a challenge to our understanding of the pathogenesis of Y. pestis. [Copyright &y& Elsevier]

Soil amendments (e.g., hydrochar) have recently gained increasing research interest because of their potential application in agricultural soils to reduce nutrient loss to the environment. In order to improve the surface properties of hydrochar, we herein used the microbial-aging approach to produce microbially-aged hydrochar (M-SHC), which was applied in rice paddy soil columns to investigate nitrogen transformation processes and gaseous nitrogen losses by NH 3 volatilization. The aim of this research was mainly to explore and understand the mechanisms by which sawdust hydrochar (SHC), M-SHC, and water-washed hydrochar (W-SHC) influence NH 3 volatilization in rice paddy fields. Compared with the control, M-SHC treatment considerably reduced both cumulative NH 3 and yield-scale NH 3 volatilization by 11.52% and 24.40% (p < 0.05), respectively. This reduction could be attributed to a decrease in NH 4 +–N concentrations and an alteration of floodwater pH, following the application of M-SHC. The results showed that changes in floodwater pH could considerably affect the NH 3 volatilization rate. When floodwater was slightly alkaline (pH > 7.25), even a minor alteration of pH following the application of hydrochar could increase NH 3 volatilization rapidly. The application of hydrochar substantially inhibited the soil urease activity and increased the soil amoA gene abundance, which, in turn, decreased the floodwater NH 4 +–N concentrations. These results offer strong theoretical support for the application of hydrochar in agricultural systems to decrease NH 3 volatilization in rice paddy fields. Note: BF, SF1, SF2 represent the basal fertilization, the first supplementary fertilization, the second supplementary fertilization respectively. Image 1 • Hydrochar was aged in a fermentation system and it was applied in rice paddy soil. • Microbially-aged hydrochar (M-SHC) significantly reduced NH 3 volatilization. • M-SHC reduced yield-scale NH 3 volatilization by 24.40% compared with CKU. • Microbially-aging process increased hydrochar's pore volume by 145.49%. • M-SHC reduced soil urease activity and elevated the abundance of amoA gene. [ABSTRACT FROM AUTHOR]