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Abstract
AbstractMorphological, anatomical and ultrastructural characteristics are important for taxonomical and phylogenetic studies of fungi. For scanning electron microscopy (SEM), usually only dry voucher specimens are available. For dried plant material, Aerosol® OT (AOT) has been shown to be a suitable rehydration agent for SEM preparation. For swelling and stabilization of fungal cells, however, this simple method does not yield satisfactory results. Here, we show that a combination of AOT with ultrasonic bath and rehydration in a vacuum desiccator is a good method to distend fungal cells like basidiospores and pleuro- and cheilocystidia for SEM analysis. Tissues of several species of Agaricomycetes with diverse morphological structures were exposed to the treatment. Diverse concentrations of AOT as well as treatments in an ultrasonic bath and a vacuum desiccator were tested to optimize the surface reconstruction and to reduce preparation artefacts. The evaluated rehydration method is a cheap, quick and nontoxic method to prepare dried specimens of fungal cells for SEM analysis.
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Li X, Sha J, Xia Y, Sheng K, Liu Y, He Y. Quantitative visualization of subcellular lignocellulose revealing the mechanism of alkali pretreatment to promote methane production of rice straw. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:8. [PMID: 31988660 PMCID: PMC6966900 DOI: 10.1186/s13068-020-1648-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/02/2020] [Indexed: 05/07/2023]
Abstract
BACKGROUND As a renewable carbon source, biomass energy not only helps in resolving the management problems of lignocellulosic wastes, but also helps to alleviate the global climate change by controlling environmental pollution raised by their generation on a large scale. However, the bottleneck problem of extensive production of biofuels lies in the filamentous crystal structure of cellulose and the embedded connection with lignin in biomass that leads to poor accessibility, weak degradation and digestion by microorganisms. Some pretreatment methods have shown significant improvement of methane yield and production rate, but the promotion mechanism has not been thoroughly studied. Revealing the temporal and spatial effects of pretreatment on lignocellulose will greatly help deepen our understanding of the optimization mechanism of pretreatment, and promote efficient utilization of lignocellulosic biomass. Here, we propose an approach for qualitative, quantitative, and location analysis of subcellular lignocellulosic changes induced by alkali treatment based on label-free Raman microspectroscopy combined with chemometrics. RESULTS Firstly, the variations of rice straw induced by alkali treatment were characterized by the Raman spectra, and the Raman fingerprint characteristics for classification of rice straw were captured. Then, a label-free Raman chemical imaging strategy was executed to obtain subcellular distribution of the lignocellulose, in the strategy a serious interference of plant tissues' fluorescence background was effectively removed. Finally, the effects of alkali pretreatment on the subcellular spatial distribution of lignocellulose in different types of cells were discovered. CONCLUSIONS The results demonstrated the mechanism of alkali treatment that promotes methane production in rice straw through anaerobic digestion by means of a systemic study of the evidence from the macroscopic measurement and Raman microscopic quantitative and localization two-angle views. Raman chemical imaging combined with chemometrics could nondestructively realize qualitative, quantitative, and location analysis of the lignocellulose of rice straw at a subcellular level in a label-free way, which was beneficial to optimize pretreatment for the improvement of biomass conversion efficiency and promote extensive utilization of biofuel.
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Affiliation(s)
- Xiaoli Li
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
- Key Laboratory of Spectroscopy Sensing, Ministry of Agriculture and Rural Areas, 866 Yuhangtang Road, Hangzhou, 310058 China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
| | - Junjing Sha
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
- Key Laboratory of Spectroscopy Sensing, Ministry of Agriculture and Rural Areas, 866 Yuhangtang Road, Hangzhou, 310058 China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
| | - Yihua Xia
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
- Key Laboratory of Spectroscopy Sensing, Ministry of Agriculture and Rural Areas, 866 Yuhangtang Road, Hangzhou, 310058 China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
| | - Kuichuan Sheng
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
- Key Laboratory of Spectroscopy Sensing, Ministry of Agriculture and Rural Areas, 866 Yuhangtang Road, Hangzhou, 310058 China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
| | - Yufei Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
- Key Laboratory of Spectroscopy Sensing, Ministry of Agriculture and Rural Areas, 866 Yuhangtang Road, Hangzhou, 310058 China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
| | - Yong He
- College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
- Key Laboratory of Spectroscopy Sensing, Ministry of Agriculture and Rural Areas, 866 Yuhangtang Road, Hangzhou, 310058 China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058 China
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Elpe C, Knopf P, Stützel T, Schulz C. Diversity and evolution of leaf anatomical characters in Taxaceae s.l.-fluorescence microscopy reveals new delimitating characters. JOURNAL OF PLANT RESEARCH 2018; 131:125-141. [PMID: 28819805 DOI: 10.1007/s10265-017-0973-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 06/16/2017] [Indexed: 06/07/2023]
Abstract
Taxaceae s.l. comprise six genera (including Cephalotaxus) and about 35 species; The present study aims to give new insights into the evolution of this family, especially into the phylogenetic position of Cephalotaxus. Moreover, only little is known about comparative leaf anatomy of this family and this study aims to expose and interpret the diversity and evolution of leaf anatomical characters and to assess their applicability to identify taxa at the generic and species level. A detailed phylogeny was reconstructed, using both maximum likelihood and Bayesian inference, with a combined dataset of four molecular markers from the plastid and nuclear genomes. Leaf sections from 132 specimens, representing 32 species and four varieties (fresh and herbarium material) were inspected, using fluorescence microscopy. Ancestral characters were reconstructed using Mesquite. The phylogenetic analyses provided full support for Cephalotaxus as sister group to Taxaceae s.str. Within the latter, two monophyletic tribes Taxeae (comprising Austrotaxus, Pseudotaxus, and Taxus) and Torreyeae (comprising Amentotaxus and Torreya) were fully supported. Fluorescence microscopy was shown to be very useful for identifying leaf tissues and their constitution. We were able to show that particularly sclerified tissues have highest potential for the discrimination of both freshly collected samples and rehydrated herbarium specimens at the generic and species level. A correlation between the presence of different sclereid types could be shown and sclereids were hypothesized to pose a primitive trait in the evolution of Taxaceae s.l. New identification keys were generated on the basis of leaf anatomical characters. The microscopic method presented here is applicable for further studies within gymnosperms and probably in angiosperms, as well.
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Affiliation(s)
- Christoph Elpe
- Department for Evolution and Biodiversity of Plants, Ruhr-Universität Bochum, Universitätsstraße 150, NDEF 05/770, 44780, Bochum, Germany.
| | - Patrick Knopf
- Botanischer Garten Rombergpark, Am Rombergpark 49b, 44225, Dortmund, Germany
| | - Thomas Stützel
- Department for Evolution and Biodiversity of Plants, Ruhr-Universität Bochum, Universitätsstraße 150, NDEF 05/770, 44780, Bochum, Germany
| | - Christian Schulz
- Department for Evolution and Biodiversity of Plants, Ruhr-Universität Bochum, Universitätsstraße 150, NDEF 05/770, 44780, Bochum, Germany
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Schilmiller AL, Stout J, Weng JK, Humphreys J, Ruegger MO, Chapple C. Mutations in the cinnamate 4-hydroxylase gene impact metabolism, growth and development in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 60:771-82. [PMID: 19682296 DOI: 10.1111/j.1365-313x.2009.03996.x] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The initial reactions of the phenylpropanoid pathway convert phenylalanine to p-coumaroyl CoA, a branch point metabolite from which many phenylpropanoids are made. Although the second enzyme of this pathway, cinnamic acid 4-hydroxylase (C4H), is well characterized, a mutant for the gene encoding this enzyme has not yet, to our knowledge, been identified, presumably because knock-out mutations in this gene would have severe phenotypes. This work describes the characterization of an allelic series of Arabidopsis reduced epidermal fluorescence 3 (ref3) mutants, each of which harbor mis-sense mutations in C4H (At2g30490). Heterologous expression of the mutant proteins in Escherichia coli yields enzymes that exhibit P420 spectra, indicative of mis-folded proteins, or have limited ability to bind substrate, indicating that the mutations we have identified affect protein stability and/or enzyme function. In agreement with the early position of C4H in phenylpropanoid metabolism, ref3 mutant plants accumulate decreased levels of several different classes of phenylpropanoid end-products, and exhibit reduced lignin deposition and altered lignin monomer content. Furthermore, these plants accumulate a novel hydroxycinnamic ester, cinnamoylmalate, which is not found in the wild type. The decreased C4H activity in ref3 also causes pleiotropic phenotypes, including dwarfism, male sterility and the development of swellings at branch junctions. Together, these observations indicate that C4H function is critical to the normal biochemistry and development of Arabidopsis.
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