通讯机构：
[Cao, Fuxiang] C;Cent South Univ Forestry & Technol, Sch Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.
关键词：
Versatile Peroxidase;Pleurotus eryngii;Agro-Industrial Waste;Saccharide- and Fatty Acid-Rich;Solid-State Fermentation;Redox Index
摘要：
Ligninolytic enzymes have attracted considerable attention in recent years due to their potential for various applications in the industrial, biotechnological, and environmental researches. Versatile peroxidase is especially important owing to its broad substrate specificity and catalytic versatility. It is produced through solid-state fermentation using agro-industrial waste as growth medium. Here, we investigated various agro-industrial waste types as alternative low-cost, easily available inducers of versatile peroxidase production from Pleurotus eryngii. Peels of fruits and vegetables, bean dregs, used tea leaves, old newspapers, and dyes were evaluated. We report that 600 mg (w/w) of banana peel, 480 mg (w/w) of corn husk, or 480 mg (w/w) of oat bran per 6 g of wheat bran increased versatile peroxidase production by 2.98-, 2.78-, and 2.34-fold, respectively, compared with those in control samples. H2O2 content and total antioxidant capacity were clearly higher and inhibition of hydroxyl radical was clearly lower in medium supplemented with banana peel, corn peel, or oat bran than that in medium containing wheat bran only. These results suggest that the improved antioxygenation of Pleurotus eryngii by those inducers had a positive effect on versatile peroxidase production. Banana peel, corn peel, and oat bran are saccharide- and fatty acid-rich and effective inducers of versatile peroxidase production from Pleurotus eryngii. Taken together, our results indicate that agro-industrial waste rich in saccharides and fatty acids may be an effective alternative to expensive chemicals required for enhanced industrial versatile peroxidase production.
通讯机构：
[Li, Meng] C;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha, Hunan, Peoples R China.
关键词：
Reference gene;Bract development;Seed abortion;Leaf color;Dove tree (Davidia involucrata Baill.)
摘要：
Key messageFifteen candidate reference genes were selected from the dove tree genome. Their performance as internal controls for RT-qPCR analysis was assessed in bracts at different developmental stages, normal and abortive seeds, and leaves of different colors. The applicability of the candidate reference genes was validated through detection of the expression levels of three target genes normalized by different reference genes.AbstractDove tree (Davidia) is a relic species and has some unique traits in its reproductive organs. The molecular mechanisms underlying the development of these organs have attracted increasing attention. RT-qPCR is a powerful tool for gene expression pattern detection, which is critical for studies on gene function or regulation. However, information regarding suitable reference genes, which ensures reliable RT-qPCR results, is absent in dove tree. Based on our previously obtained Davidia transcriptome data, 15 reference genes, including eight traditional and seven novel reference genes, were selected for this study. Using geNorm, NormFinder and BestKeeper software, the stability and applicability of these candidate reference genes were assessed with regard to different aspects including bract development, seed abortion and leaf color. The candidate reference genes were ranked by the software programs, and the most suitable and unsuitable genes for different situations were determined. In addition, the expression levels of three Davidia genes of interest involved in bract development, seed abortion and leaf color, respectively, were normalized with high-ranking and low-ranking reference genes. The comparison results demonstrated that the selection of good or bad reference genes led to differing conclusions.
关键词：
6-APA;Bacillus sphaericus;Directed evolution;Penicillin V acylase (PVA)
摘要：
Penicillin acylase is commonly used to produce the medical intermediates of 6-Aminopenicillanic acid (6-APA) and 7-Aminodesacetoxycephalosporanic acid (7-ADCA) in industrial process. Nowadays, Penicillin G acylase (PGA) has been widely applied for making pharmaceutical intermediates, while penicillin V acylase (PVA) has been less used for that due to its low activity and poor conversion. In this study, a PVA from Bacillus sphaericus (BspPVA) was employed for directed evolution study with hoping to increase its catalytic efficiency. Finally, a triple mutant BspPVA-3 (T63S/N198Y/S110C) was obtained with 12.4-fold specific activity and 11.3-fold catalytic efficiency higher than BspPVA-wt (wild type of BspPVA). Moreover, the conversion yields of 6-APA catalyzed by BspPVA-3 reached 98% with 20% (w/v) penicillin V as substrate, which was significantly higher than that of the BspPVA-wt (85%). Based on the analysis of modeling, the enhancement of specific activity of mutant BspPVA-3 was probably attributed to the changes in the number of hydrogen bonds within the molecules. The triple mutant PVA developed in this study has a potential for large-scale industrial application for 6-APA production.
通讯机构：
[Cao, FX; Liu, ZM] C;[Liu, Zhiming] E;Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Minist Educ, Coll Life Sci & Technol, Changsha, Hunan, Peoples R China.;Eastern New Mexico Univ, Dept Biol, Portales, NM 88130 USA.
关键词：
Transcriptome;Adversity stress;Phytohormone;Seed abortion;Integument;Dove tree (Davidia involucrata Baill.)
摘要：
Dove tree (Davidia involucrata Baill.) is a rare and endangered species. Natural reproduction of dove tree is extremely difficult due to its low fecundity. Serious seed abortion is one of the key factors restraining its sexual reproduction. Understanding the inducements of seed abortion is critical for addressing the issue of offspring production and the survivability of such an endangered species. However, studies on the molecular mechanism of seed abortion in woody plants are lacking, and the dearth of genomic resources for dove tree restricts further research. In this study, using the Illumina platform, we performed de novo transcriptome sequencing of the fruit and seed in dove tree. A total of 149,099 transcripts were isolated and then assembled into 72,885 unigenes. Subsequently, differentially expressed genes (DEGs) between normal and abortive seeds were screened. Genes involved in response to stress, hormone signal transduction, programmed cell death, lignin biosynthesis, and secondary cell wall biogenesis showed significant different expression levels between normal and abortive seeds. Combined results indicated that the abortive seeds were under the adversity stress, which should be controlled by the maternal plant. Maternally controlled development of integument is assumed to be a critical process for abortion regulation. MYB and WRKY transcription factors, receptor kinase and laccase are considered to be important regulators in seed abortion. Moreover, mass sequence data facilitated further molecular research on this unique species.
作者：
Xie, L. W.;Zhong, J.;Chen, F. F.;Cao, F. X.;Li, J. J.;...
期刊：
SOLID EARTH,2015年6(2):515-524 ISSN：1869-9510
通讯作者：
Wu, L. C.
作者机构：
[Chen, F. F.; Zhong, J.; Xie, L. W.; Wu, L. C.; Li, J. J.] Cent South Univ Forestry & Technol, Minist Educ, Key Lab Cultivat & Protect Nonwood Forest Trees, Changsha 410004, Hunan, Peoples R China.;[Cao, F. X.] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wu, L. C.] C;Cent South Univ Forestry & Technol, Minist Educ, Key Lab Cultivat & Protect Nonwood Forest Trees, Changsha 410004, Hunan, Peoples R China.
摘要：
<jats:p>Abstract. Expanding of karst rocky desertification (RD) area in southwestern China is strangling the sustainable development of local agricultural economy. It is important to evaluate the soil fertility at RD regions for the sustainable management of karst lands. The changes in 19 different soil fertility-related variables along a gradient of karst rocky desertification were investigated in five different counties belonging to the central Hunan province in China. We used principal component analysis method to calculate the soil data matrix and obtained a standardized integrate soil fertility (ISF) indicator to reflect RD grades. The results showed that the succession of RD had different impacts on soil fertility indicators. The changing trend of total organic carbon (TOC), total nitrogen (TN), available phosphorus, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) was potential RD (PRD) > light RD (LRD) > moderate RD (MRD) > intensive RD (IRD), whereas the changing trend of other indicators was not entirely consistent with the succession of RD. The degradation trend of ISF was basically parallel to the aggravation of RD, and the strength of ISF mean values were in the order of PRD > LRD > MRD > IRD. The TOC, MBC, and MBN could be regarded as the key indicators to evaluate the soil fertility.
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