An anatomically preserved lepidodendralean stem is described from coal balls of the early Early Permian or late Late Carboniferous Taiyuan Formation in Tao-Zao and Yanzhou coal fields from southern Shandong, North China. The stem bears leaf cushions previously assigned into “Lepidodendron” tachingshanense Lee, but is renamed as “Lepidodendron” tripunctatum Stock. et Math. based on the morphology of the leaf cushion in this study. Comparison and relationship between “L.” tripunctatum and other anatomically preserved lepidodendralean stems from the middle Late Carboniferous Euramerican and the late Late Carboniferous or early Early Permian Cathaysian floras is made and discussed.
We report a new species of the genus Weltrichia Braun with a special Bennettitalean male reproductive organ—W. daohugouensis Li et Zheng sp. nov., which was discovered from Haifanggou Formation (Middle Jurassic) in Daohugou Village, Shantou Town, Ningcheng County, Inner Mongolia (Nei Mongol) Autonomous Region, China. It is a unisexual male strobile which was a laterally compressed preserved specimen being fan-shaped and appearing as half of a whole. Its base and peduncle are lost while the lower part of the strobile consists of eleven narrowly wedged segments fused together into a funnel or cup-like. In the upper part of the strobile these segments separate into free structure (microsporophylls), each bearing two rows of pollen sacs (synangia). In this paper a new species W. daohugouensis Li et Zheng sp. nov. is described and the identification of the W. huangbanjigouensis Sun et Zheng is emended.
This paper deals with the new leaf-like rhodophycean fossils in the Early Cambrian from Chengjiang Biota at Mafang Village of Haikou, Kunming, Yunnan, Southeast China. The new taxa Paradelesseria sanguinea gen. et sp. nov. is found to have a close relationship with the living Delesseria according to detailed morphological study between the fossil and modern Delesseria. These new findings show that the Chengjiang Biota is high in species diversity of fossil algae and might offer new evidence for a better understanding of the Cambrian explosive biological evolution and its paleoenvironment. The Biota in Haikou district of Kunming was living in subtidal and lower intertidal marine environment, up to 30 m below surface of the water based on the comparative study of extant red algae.
An ecosystem process model, BIOME-BGC, was used to explore the sensitivity of net primary productivity (NPP) of an oak (Quercus liaotungensis Koidz) forest ecosystem in Beijing area to global climate changes caused by increasing atmospheric CO2 concentrations. Firstly we tested the model, and validated the modeled outputs using observational data; the outputs of BIOME-BGC model were consistent with observed soil water content and annual NPP. Secondly the potential impacts of climate change on the oak forest ecosystem were predicted with BIOME-BGC model. We found that the simulated NPP was much more sensitive to a 20% precipitation increase or a doubling of atmospheric CO2 from 355 to 710 祄ol/mol than to a 2 ℃ temperature increase. Our results also indicated that the effects of elevated CO2 and climate change on the response of NPP were not interactive.
Role and relationship of NO and H2O2 in light/dark-regulated stomatal movement in Vicia faba L. were investigated by epidermal strip bioassay and laser-scanning confocal microscopy. Results showed that the effects of exogenous sodium nitroprusside (SNP, NO-releasing compound) and H2O2 on stomatal closure were more significant in light than those in the dark. Dark-induced closure of stomata was largely prevented not only by 2,4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), a specific NO scavenger and NG-nitro-L-arg-methyl eater (L-NAME), an inhibitor of NO synthase (NOS) in mammalian cells that also inhibits plant NOS, but also by addition of ascorbic acid (Vc) and exogenous catalase (CAT), which are an important reducing substrate for H2O2 removal and an H2O2 scavenger, respectively. Experiments based on fluorescent probe DAF-2 DA and H2DCF-DA showed that the level of endogenous NO and H2O2 in guard cells was greater in the dark than that in light. These results prove that light/dark regulates stomatal movement via influencing NO and H2O2 production. In addition, H2O2-induced NO production and stomatal closure in light were abolished partly by cPTIO and L-NAME. Interestingly, SNP-induced H2O2 accumulation and stomatal closure were reversed by Vc and CAT in light. These show that NO and H2O2 cross talk in light/dark-regulated stomatal movement. Furthermore, L-NAME could reverse stomatal closure and NO generation induced by darkness and H2O2 in light, we presume that the NO generation in guard cells of Vicia faba is likely related to NOS-like enzyme.
A new mannose-binding agglutinin gene was cloned from bulbs of Amaryllis vittata Ait. The full-length cDNA of A. vittata agglutinin (AVA) was 686 bp. The start codon of ava cDNA was at 41-43 bp and the stop codon was at 515-517 bp. Analysis in the BLAST of GenBank showed that ava gene encodes a protein precursor composed of a signal peptide, mature protein and C-terminal amino acid cleavage sequence. The mature protein of AVA includes 109 amino acid residues and the molecular weight is 11.9 kD. The homologous analysis showed that the identity between AVA and Galanthus nivalis agglutinin, Narcissus hybrid cultivar agglutinin, Lycoris radiata agglutinin, Clivia miniata agglutinin are 73.4%, 85.3%, 80.7%, 83.5%, respectively. Molecular modeling of AVA indicated that its three-dimensional structure strongly resembles that of the snowdrop agglutinin. Blocks’ analysis revealed that the deduced amino acid sequence of AVA has three functional domains specific for agglutination and three carbohydrate-binding boxes (QDNY).
Exogenous nitric oxide (NO) releaser sodium nitroprusside (SNP) with different concentrations from 0.01 to 5.00 mmol/L induced proline accumulation in wheat (Triticum aestivum L. cv. Yangmai 158) seedling leaves under 150 mmol/L salt stress in a dose-dependent manner. It was most effective at 0.1 mmol/L SNP, and the combination treatments with two NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) and hemoglobin, separately reverted the 0.1 mmol/L SNP induced proline accumulation. Meanwhile, the proline accumulation induced by NO might be of benefit to the water retention in wheat seedling leaves when subjected to salinity, and exogenous 0.1 mmol/L SNP treatment also dramatically activated the synthesis of endogenous abscisic acid (ABA), and the employment of hemoglobin further indicated that NO might be downstream of the ABA induced proline accumulation in wheat seedling leaves under 150 mmol/L salt stress, but there did not exist synergism between NO and ABA signaling toward proline accumulation. Detection of proline synthesis and degradation demonstrated that exogenous NO induced proline accumulation in a phase dependent manner, mainly by enhancing the activities of D1-pyrroline-5-carboxylate synthetase (P5CS) within the first 4 d of treatment and inhibiting activities of proline dehydrogenase (ProDH) 4 d later up to 8 d. And ABA showed a weak effect on P5CS and ProDH activities in comparison with NO treatment. Additionally, Ca2+ was confirmed as the important intermediates during the NO signaling pathway in proline accumulation under salinity conditions.
Dynamics of leaf mass (LM), leaf area (LA) and element retranslocation efficiency during leaf senescence was investigated in Phyllostachys pubescens Mazel ex H. de Lehaie in Yongchun, Fujian, China. Comparison of differences in element retranslocation efficiencies (RE) based on per gram leaf dry weight, per leaf and per LA during leaf senescence was carried out. With leaf senescence, the mean decreases of LM, LA and specific leaf mass (SLM) were 19.55%, 15.16% and 5.07%, respectively. The seasonal changes in decrease percentage of LM and LA were similar, indicating that certain mass to area ratios occurred in P. pubescens leaves. On different bases, RE of N and K was positive, while RE of Ca was negative, suggesting that with leaf senescence, N and K were translocated out of senescing leaves to other parts of plant, while Ca accumulated in senescing leaves. For the mean RE of N, P, K, Ca and Mg on different bases, the rank order was RE2 (mg element/leaf)＞RE3 (mg element/cm2 leaf)＞RE1 (mg element/g), therefore, RE on the basis of leaf weight or LA would be underestimated.
The yeasts Trichosporon pullulans (Lindner.) Diddens et Lodder, Cryptococcus laurentii (Kuffer.) Skinner and Rhodotorula glutinis (Fresenius) Harrison were sprayed at concentration of 1×108 CFU/mL onto sweet cherry (Prunus avivum L. cv. Hongdeng) fruit in two orchards prior to harvest. Survival of these species on fruit surfaces under field conditions was investigated. Also, their biocontrol efficacy against postharvest decay of cherry fruit stored under various conditions was assessed. All three yeasts colonized the surface of sweet cherry fruit. However, only C. laurentii and R. glutinis maintained populations at high and stable levels throughout the 4-d experimental period. C. laurentii was the most effective and promising of the three antagonists. It had strong survival ability on fruit surfaces under field conditions and adaptability to postharvest storage conditions of low temperature, low-O2 and high-CO2 concentrations.
While attempting to obtain large crystals of nitrogenase CrFe protein, brown crystals and brick red crystals were simultaneously or independently obtained from CrFe protein preparation, which was partially purified from a mutant UW3 of Azotobacter vinelandii Lipmann grown on Mo-, ammonia-free but Cr-containing medium. SDS-PAGE and anoxic native-PAGE analysis consistently showed that the protein of the brown crystal was mainly composed of subunits (～60 kD) similar to those of Av1 (MoFe protein), while the protein of the brick red crystal was composed of ～20 kD subunits. And only the larger subunits rather than the smaller ones were detectable by Western blot to the antibody of Av1. Comparing with the large subunits, the amount of the small subunits in the partially purified CrFe protein solution was much smaller, indicating that the protein composed of the smaller subunits was one of contamination proteins for CrFe protein. Detection by 3, 5-diaminobenzoic acid of native-PAGE gels showed that the proteins forming the brick red crystal and the brown crystal were two kinds of iron-containing proteins with different electrophoretic mobility on the gel. The analysis of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) proved that the protein forming the brick red crystal was bacterioferritin of A. vinelandii (AvBF). X-ray diffraction to 2.34 Å resolution showed that the crystal belonged to space group H3, with unit-cell parameters a = 124.965 Å, b=124.965 Å and c = 287.406 Å. The detailed structural analysis published in the near future has confirmed that the brick red crystal is that of 24-meric bacterioferritin.
A full-length cDNA (apod1) encoding a peroxidase was isolated from Artemisia annua L. using rapid amplification of cDNA end (RACE) strategy. The peroxidase activity of recombinant protein (APOD1) expressed in E. coli BL21 (DE3) pLysS cells was about 1.8-fold higher with guaiacol than ascorbate, which indicated that APOD1 was a plant classical peroxidase (class Ⅲ peroxidase). The deduced amino acids of apod1 had 42.0% homology to the peroxidase from Lupinus albus, 36.2% to Armoracia rusticana, 38.9% to Triticum aestivum, 33.6% to Nicotiana tabacum and 32.8% to Lycopersicon esculentum, respectively. Northern blotting analysis showed that apod1 was expressed in the roots, stems and leaves of A. annua. APOD1 favored the bioconversion of artemisinic acid to artemisinin in the cell-free extracts of A. annua indirectly but no oxidization with artemisinic acid as the only substrate. Key words: Artemisia annua ; artemisinic acid; artemisinin; peroxidase
Here we report the isolation and expression of a pollen-specific cDNA TaPSG719 with an unusually long 5'' leader sequence via suppression subtractive hybridization and 5''/3'' RACE techniques. The insert in the TaPSG719 is 1 172-bp long, and encodes a protein of 188 amino acids long with a pI of 12.1. This sequence did not show a significant homology to any genes deposited in the public database by BLAST search. Southern blot indicated that TaPSG719 might be multicopy. Northern blot and RT-PCR analyses indicated that TaPSG719 transcripts were specific for mature pollen, and undetectable in microspore, immature seed, stem, young leaf, root and ovary. During pollen development, TaPSG719 transcripts were first detectable on the 5th day before anthesis and increased rapidly at middle stages of pollen development with maximum levels on the 4th day before anthesis, and decreased during pollen maturation. It is noted that TaPSG719 contains an unusually long 5'' leader sequence (329-nt) upstream the ATG start codon, suggesting that the gene could be subject to translational regulation. To investigate the role of the 5'' UTR on translation, in vitro transcription/translation assays with various deletion and mutation constructs were performed using wheat germ extract. The results demonstrated that the 5'' UTR affected positively downstream translation in wheat germ extract.
Chromosome 6B of wheat (Triticum aestivum L.) in mitotic metaphase spreads was micro-dissected with Nd:YAG laser microbeam into four segments and then each segment was collected by glass needles. The DNAs of the isolated chromosomal segments were separately amplified by Sau3A linker adaptor-mediated polymerase chain reaction (LA-PCR). The presence of region-specific DNA from each of four segments was verified by Southern hybridization. The second round PCR products from four segments of chromosome 6B were cloned into a pGEM T-vector to create four chromosome region-specific libraries, named R1, R2, R3 and R4, which included 2.1×105; 2.74×105; 2.45×105 and 2.93×105 recombinant clones, respectively. A total of 150 randomly selected clones from each library were characterized by mini plasmid DNA preparation and enzyme restriction. Results showed that the size of inserts ranged from 300 to 1 800 bp with an average of 820 to 870 bp, of which 43%-48% were low/unique copy and 42%-47% were medium/high copy sequences. A set of microsatellite sequences located on chromosome 6B and other chromosomes of wheat were used for the verification of PCR products from micro-dissected chromosomal segments. The results reported here should facilitate the molecular genetics analysis of different fragments from single chromosomes of a plant.
Ubiquitin fusion degradation (UFD) protein, encoded by the UFD1 gene that was first described in yeast, is a key component in this Ub-dependent degradation system or Ub fusion degradation pathway. We isolated a UFD1 -like gene in wheat (Triticum aestivum L.) through RT-PCR. The entire coding region is 948 bp and encodes a polypeptide of 315 amino acids with 74% homology to a UFD1-like protein of Arabidopsis deposited in the GenBank. Its N-terminal possesses the so-called UFD1 domain highly conserved among eukaryotic organisms. This gene was designated as TUFD1 and mapped to group 6 chromosomes of wheat. Southern hybridization and database search demonstrated that UFD1 genes in plants are in single copy or low copies. Plant UFD1 proteins have three highly conserved C-terminal domains besides the UFD1 domain and are highly homologous to one another. TUFD1 showed a constitutive expression pattern in roots, stems, coleoptiles, and leaves of seedlings, and in young spikes and seeds at the hard-dough ripening stage.
Using degenerate primers based on conserved regions of the UDP-glucose dehydrogenase (UDPGDH) gene, an initial 476-bp DNA fragment was amplified from the water-bloom forming cyanobacterium, Microcystis aeruginosa FACHB 905. TAIL-PCR and ligation-mediated PCR were used to amplify the flanking regions to isolate an about 2.5-kb genomic DNA fragment. Sequence analysis revealed an ORF encoding a putative 462 amino acid protein, designated Mud for Microcystis UDPGDH. The Mud amino acid sequence is closely related to UDPGDH sequences from cyanobacterium Synechocystis PCC6803 (73% identity, 81% similarity), and bacterium Bacillus subtilis (51% identity and 67% similarity). The cloned mud gene was expressed in Escherichia coli using the pGEX-4T-1 fusion expression vector system to generate a GST-Mud fusion protein that exhibited UDPGDH activity. The cytosolic fraction of M. aeruginosa FACHB 905 was subjected to Western analysis with an anti-Mud antibody, which revealed a single band of approximately 49 kD, consistent with the deduced molecular mass of the enzyme. The Mud protein could thus be characterized as a UDP-glucose dehydrogenase, which was a key enzyme for polysaccharide synthesis and has, for the first time, been studied in algae.
The biotransformation of paclitaxel (TaxolⓇ) by the cell suspension cultures of Rauwolfia serpentina (L.) Benth. et Kurz. were investigated. Three Paclitaxel-based intracellular metabolites were detected from the cell filter cake and were, by high field 1H-NMR and MS data, identified as 10-deacetyltaxol, baccatin Ⅲ, and 10-deacetylbaccatin Ⅲ. No glucosidated or hydroxylated derivatives were checked out in this incubation experiment.
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