Characterisation of the subunit genes of pyrophosphate-dependent phosphofructokinase from loquat (Eriobotrya japonica Lindl.)

Pyrophosphate-dependent phosphofructokinase (PFP) catalyses the reversible phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate in the glycolysis pathway. Two full-length complementary DNAs encoding putative PFP α- and β-subunits, named EjPFPa and EjPFPb1, were isolated by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of the cDNA ends (RACE) from Eriobotrya japonica Lindl. (loquat). The other β-subunit gene was identified from transcriptome data obtained by Illumina sequencing, designated as EjPFPb2. They share up to 88 % identity with other plant PFP α/β-subunits. EjPFPa and EjPFPb clustered separately in clades of plant PFP α- or β-subunits, respectively. EjPFPa and EjPFPb were both shown to be mainly localised in the cell membrane using confocal microscopy of GFP fusion proteins 35S:EjPFPa/b-GFP. Monitoring the dynamic changes of transcripts and proteins demonstrated that EjPFPa and EjPFPb did not show coordinated expression during fruit development in loquat. The transcript levels of EjPFPa and EjPFPb in the leaves of loquat seedlings were significantly enhanced after 3 h of treatment with 0.5, 1.0 and 1.5 M fructose or glucose, which indicates that EjPFPa and EjPFPb are modulated by fructose and glucose in vivo. Transgenic tobacco plants overexpressed EjPFPa did not show visible phenotype changes, while plants overexpressing EjPFPb1 grew faster at the cost of reduced leaf size and sucrose content. Meanwhile, fructose content increased in growing plants compared with wild-type plants. The results confirm that genes of the two subunits from loquat PFP have different transcriptional regulation systems and play different roles in carbohydrate metabolism. Elevation of the PFP β-subunit gene expression can partly impact the glycolytic carbon allocation in growing plants

Sustainability Assessment of a Qingyuan Mushroom Culture System Based on Emergy

The Qingyuan mushroom culture system (QMCS) in Zhejiang Province has been recognized as the source of the world’s first artificial cultivation of mushrooms with a history of more than 800 years. The system embodies the farming wisdom of the local people who have adapted themselves to and utilized nature and has integrated the traditional bark hacking method with multiple modern patterns for mushroom cultivation based on artificial microbial strains. We have investigated the input–output operation of farmers and assessed and analyzed emergy indicators in a bid to reflect and compare their economic and ecological benefits, as well as their sustainable development by analyzing the three typical mushroom cultivation patterns. The cost-benefit analysis of the three patterns shows that the sawdust medium-cultivated method (SMCM) is characterized by dominance in both net income without labor cost and labor productivity; while the evaluation based on emergy indicators has proven that each has its own advantages and disadvantages in terms of ecological and economic benefits and sustainable development. Among them, the bark hacking method (BHM) features the highest utilization rates of local and renewable resources, the smallest damage to the environment, the lowest production efficiency, and the highest exchange efficiency, but the sawdust medium-cultivated method is just the opposite, and the log-cultivated method (LCM) is the most favorable one for sustainable development. As its agricultural heritage, the QMCS’ core of dynamic protection and adaptive management lies in enhancing the sustainable development of its agricultural production methods. It is recommended that the three patterns be improved by targeting their respective shortcomings and at the same time, integrate their advantages to explore a new sustainable development pattern for mushroom cultivation

Emergy-Based Sustainability Evaluation of the Mulberry-Dyke and Fish-Pond System on the South Bank of Taihu Lake, China

The Taihu Lake drainage basin is the birthplace of the Mulberry-dyke and Fish-pond System (MFS), a traditional eco-agricultural system. In 2017, the largest and best-preserved “Zhejiang Huzhou Mulberry-dyke and Fish-pond System” located by the South Bank of Taihu Lake, China was recognized as Globally Important Agricultural Heritage Systems (GIAHS) by the Food and Agriculture Organization of the United Nations (FAO), and its value has been appreciated. As a dynamic heritage, the sustainable development of MFS is a fundamental requirement of the conservation of GIAHS. In this regard, it is necessary to figure out an approach to evaluating the status of its sustainable development. This paper analyzes and contrasts the emergy embodied in the three patterns of MFS over different periods, then constructs an index system of sustainability evaluation involving the production and consumption processes based on that. Finally, it provides the evaluation and analysis. The three patterns of MFS differ in the system structure. In the Ming and Qing Dynasties (abbreviated as Ming-Qing pattern), MFS was an integrated system compromised of mulberry cultivation, silkworm breeding, fish breeding, and sheep breeding, while other patterns exclude sheep breeding, but increase the input of fertilizer, and add the production of mulberry-leaf tea and other local specialties. The results show that the MFS in the Ming-Qing pattern has the highest integrated evaluation index of sustainable development, followed by the traditional MFS pattern and the new MFS pattern employed nowadays. This indicates that the current capability of sustainable development has decreased compared to that in the Ming and Qing Dynasties. The integrated evaluation index regarding the consumption process of the new MFS pattern is higher than the traditional one, suggesting that it needs to promote sustainability in the production process, especially via the utilization rates of renewable resources and wastes

Comparative de novo transcriptomics and untargeted metabolomic analyses elucidate complicated mechanisms regulating celery (Apium graveolens L.) responses to selenium stimuli.

Presently, concern regarding the effects of selenium (Se) on the environment and organisms worldwide is increasing. Too much Se in the soil is harmful to plants. In this study, Illumina RNA sequencing and the untargeted metabolome of control and Se-treated celery seedlings were analyzed. In total, 297,911,046 clean reads were obtained and assembled into 150,218 transcripts (50,876 unigenes). A total of 36,287 unigenes were annotated using different databases. Additionally, 8,907 differentially expressed genes, including 5,319 up- and 3,588 downregulated genes, were identified between mock and Se-treated plants. "Phenylpropanoid biosynthesis" was the most enriched KEGG pathway. A total of 24 sulfur and selenocompound metabolic unigenes were differentially expressed. Furthermore, 1,774 metabolites and 237 significant differentially accumulated metabolites were identified using the untargeted metabolomic approach. We conducted correlation analyses of enriched KEGG pathways of differentially expressed genes and accumulated metabolites. Our findings suggested that candidate genes and metabolites involved in important biological pathways may regulate Se tolerance in celery. The results increase our understanding of the molecular mechanism responsible for celery's adaptation to Se stress

Isolation and characterization of a cytosolic pyruvate kinase cDNA from loquat (Eriobotrya japonica Lindl.)

Pyruvate kinase catalyzes the final reaction of glycolysis, and plays an important role in controlling glycolytic flux. In this study, a full-length cDNA of a putative Eriobotrya japonica Lindl. (loquat) pyruvate kinase, designated EjPK, was isolated. The nucleic acid sequence of EjPK shares about 78-84 % similarity with already studied plant cytosolic pyruvate kinases. EjPK belongs to the cytosolic-1 subgroup of pyruvate kinase, which includes grape, soybean, and citrus cytosolic pyruvate kinases. The cytosolic localization was confirmed by confocal microscopy using transiently expressed 35S:EjPK-GFP fusion protein. Real-time RT-PCR indicated that EjPK is expressed in loquat leaves, roots, stems, flowers, and fruits. Loquat fruits ripen in two stages: in the first stage, the acid content increases, and in the second stage, acids are consumed and at the same time sugars accumulate. EjPK displayed a remarkable expression pattern in the developing fruit as EjPK transcripts increased dramatically and transiently during the transition period between the two stages. The burst of EjPK mRNA expression had greater intensity in a loquat cultivar displaying higher fruit sugar content than in a cultivar with lower fruit sugar concentration. A potential regulatory role of EjPK in loquat fruit ripening is proposed

Comparative proteomic analysis of pepper (Capsicum annuum L.) seedlings under selenium stress

Selenium (Se) is an essential trace element for human and animal health. Se fertilizer has been used to increase the Se content in crops to meet the Se requirements in humans and animals. To address the challenge of Se poisoning in plants, the mechanisms underlying Se-induced stress in plants must be understood. Here, to elucidate the effects of Se stress on the protein levels in pepper, we used an integrated approach involving tandem mass tag labeling, high performance liquid chromatography fractionation, and mass spectrometry-based analysis. A total of 4,693 proteins were identified, 3,938 of which yielded quantitative information. Among them, the expression of 172 proteins was up-regulated, and the expression of 28 proteins was down-regulated in the Se/mock treatment comparison. According to the above data, we performed a systematic bioinformatics analysis of all identified proteins and differentially expressed proteins (DEPs). The DEPs were most strongly associated with the terms “metabolic process,” “posttranslational modification, protein turnover, chaperones,” and “protein processing in endoplasmic reticulum” according to Gene Ontology, eukaryotic orthologous groups classification, and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, respectively. Furthermore, several heat shock proteins were identified as DEPs. These results provide insights that may facilitate further studies on the pepper proteome expressed downstream of the Se stress response. Our data revealed that the responses of pepper to Se stress involve various pathways