Isotope-based water-use efficiency of major greening plants in a sponge city in northern China.

To tackle urban water issues, the Chinese government has promoted the construction of sponge cities in recent years. Thirty cities have been designated as experimental sites to serve as models for future sponge city construction, as more than 80% of the built-up urban areas in China must reach the standards of sponge cities by 2030. Greening plants play an important role in sponge cities, and water-use efficiency (WUE) is a vital index to determine whether plants could adapt to and grow healthily in environments with water deficits. In this study, WUE of greening plants was quantified by measuring the stable carbon isotope fractionation. Suitable plants for the green spaces in Guyuan sponge city, in northern China, were selected based on their WUE, and the main factors affecting WUE were studied in four habitats within the city. Plant species identity had the greatest effect on WUE, while habitat and plant life form had lower effect, illustrating that WUE is a relatively stable and reliable index for the classification of plant species. We can improve the WUE and ecological function of green spaces in sponge cities by using isotope technology to select suitable plant species with high WUE. To our knowledge, this study is the first to select plant species for sponge city by using this method, providing a quick and scientific method for the selection of greening plants for future sponge cities.

In vitro inhibitory properties of sesquiterpenes from Chloranthus serratus on cell motility via down-regulation of LIMK1 activation in human breast cancer.

BACKGROUND: LIM kinase 1 plays an important role in tumor cell invasion and metastasis by regulating architecture of actin cytoskeleton, and inhibiting activity of this kinase may be a promising strategy to prevent cancer cells from distant spread. In our previous studies, we found several extracts from the medical herbs in genus Chloranthus to exhibit anti-metastatic effects. PURPOSE: The aim of this study is to find LIMK1 inhibitors from Chloranthus serratus, a medical herb from genus Chloranthus and to evaluate their effects on cell motility. METHODS: Three sesquiterpenes, chloranthalactone E (compound 1), serralactone A (compound 2, SERA is used in the further testing), and 8ß, 9α-dihydroxylindan-4(5), 7(11)-dien-8α, 12-olide (compound 3) were isolated from Chloranthus serratus, and the anti-LIMK1 activities of these compounds were investigated by kinase-Glo® luminescent kinase assay. Then, the anti-LIMK1 properties of SERA were verified by kinase-Glo® luminescent kinase assay and western blot assay. The effects of SERA on F-actin polymerization and cell migration were investigated by Phalloidin dying, AP 48 chamber system and ORIS™ cell migration assay. Furthermore, the inhibitory effects of SERA on LIMK1 were confirmed by overexpression of LIMK1 and small interfering RNA (siRNA) mediated gene silencing. RESULTS: we reported here that among the three sesquiterpenes, SERA showed significantly inhibition on LIMK1 activity, and the IC50 values on MDA-MB-231 and MDA-MB-468 cells were 3.14 µM and 4.64 µM, respectively. Furthermore, it was also found that SERA significantly suppressed LIMK1 and cofilin1 phosphorylation, F-actin polymerization and also cell migration. Data from LIMK1 overexpression and RNA interfering assay confirmed that the inhibitory effects of SERA on LIMK1 was antagonized and enhanced by the overexpression and knockdown of LIMK1. CONCLUSION: collectively, it was concluded that SERA exhibited significant inhibitory effects on breast cancer cells migration, and these effects of this sesquiterpene are due to its properties reducing the activation of LIM kinase 1.

Extraction and Quantification of Lipids from Plant or Algae.

In plants and algae, the glycerolipidome changes in response to environmental modifications. For instance, in phosphate starvation, phospholipids are degraded and replaced by nonphosphorus lipids and in nitrogen starvation, storage lipids accumulate. In addition to the well-known applications of oil crops for food, algae lipids are becoming a model for potential applications in health, biofuel, and green chemistry and are used as a platform for genetic engineering. It is therefore important to measure accurately and quickly the glycerolipid content in plants and algae. Here we describe the methods to extract the lipid, quantify the fatty acid amount of the lipid extract and to quantify the different lipid classes that are present in these samples.

Functions and Evolution of Lhcb Isoforms Composing LHCII, the Major Light Harvesting Complex of Photosystem II of Green Eukaryotic Organisms.

Oxygenic photosynthesis provides energy and oxygen for almost all forms of life on earth. This process is based on the energy of photons, which is used to split water and use its electrons to reduce carbon atoms to create organic molecules and thus fix the light energy into a chemical form. Two photosytems working in series are involved in light harvesting and conversion. Both are multi-protein supercomplexes composed of a core complex, where the photochemical reaction takes place, and an antenna system involved in light harvesting. In plants and green algae, the antenna of photosystem II, the photosynthetic complex involved in water splitting, comprises the Light Harvesting Complex II (LHCII) trimers, the most abundant membrane protein on earth. LHCII is composed of highly conserved Lhcb isoforms and all green organisms count a high number of Lhcb. In vascular plants they are classified in three distinct subclasses, Lhcb1, 2 and 3, while in algae and non-vascular plants, these isoforms are less differentiated and called Lhcbm proteins. In this review, we compare LHCII proteins of different organisms, from green algae to angiosperms, and discuss the role of the modifications that occurred through evolution. We highlight the various functions of the different isoforms in photosynthesis, ranging from light harvesting, a common role to all these proteins, to regulations of photosynthesis that rely on specific isoforms.

The evolution of hydrophobic cell wall biopolymers: from algae to angiosperms.

The transition from an aquatic ancestral condition to a terrestrial environment exposed the first land plants to the desiccating effects of air and potentially large fluctuations in temperature and light intensity. To be successful, this transition necessitated metabolic, physiological, and morphological modifications, among which one of the most important was the capacity to synthesize hydrophobic extracellular biopolymers such as those found in the cuticular membrane, suberin, lignin, and sporopollenin, which collectively reduce the loss of water, provide barriers to pathogens, protect against harmful levels of UV radiation, and rigidify targeted cell walls. Here, we review phylogenetic and molecular data from extant members of the green plant clade (Chlorobionta) and show that the capacity to synthesize the monomeric precursors of all four biopolymers is ancestral and extends in some cases to unicellular plants (e.g. Chlamydomonas). We also review evidence from extant algae, bryophytes, and early-divergent tracheophytes and show that gene duplication, subsequent neo-functionalization, and the co-option of fundamental and ancestral metabolic pathways contributed to the early evolutionary success of the land plants.

Evaluation of heavy metal pollution in water wells and soil using common leafy green plant indicators in the Al-Kharj region, Saudi Arabia.

This study was performed to determine the levels of eight heavy metals in irrigation well water and soil and to assess the suitability of some leafy green plants that are commonly cultivated in the Al-Kharj region, Saudi Arabia, for human consumption using an atomic absorption spectrometer. The mean concentrations of metals ranged from 0.0001 to 0.436 mg/L in well water and from 0.248 to 164.52 mg/kg in soil. The heavy metal concentrations showed significant differences among the different leafy green plants studied. Parsley (4.98 mg/kg) exhibited higher levels of Pb than other leafy green plants, whereas mallow (0.097 mg/kg) revealed greater amounts of Cd than other plants. All of the leafy green plants retained essential metals (Cu, Zn, Fe and Mn) more than the toxic metals (Pb and Cd). The levels of some of the metals in the leafy green plants were found to meet the FAO/WHO-recommended limits. The monitoring of heavy metals in leafy green plants must be continued because these plants are the main source of food for humans in many parts of the world and are considered to be bio-indicators for environmental pollution.

Oral administration of green plant-derived chemicals and antioxidants alleviates stress-induced cellular oxidative challenge.

BACKGROUND: This study examined the efficacy of the combination antioxidant, Formula 42 (F42), on cellular stress indicators in animal and human models of stress-induced oxidative stress. METHODS: A sub-chronic psychological stress model in rodents was used to induce stress and oxidative stress indicators over a 10-day period during which animals received oral doses of F42 or water. Following treatment, body weight, plasma stress hormone corticosterone, and oxidative capacity were evaluated. In healthy human subjects, a randomized double-blind crossover study was used to examine the antioxidant effect of F42 or placebo in an exercise-induced oxidative stress model. Erythrocyte and plasma oxidative status was evaluated using the fluorescent activation of 2',7'-dichlorofluorescin (DCF) as an indicator. RESULTS: Oral administration of F42 reduced the corticosterone response to acute stress compared to vehicle but did not differ at the conclusion of the 10-day study. However, F42 administration did reduce stress-induced growth restriction and alleviate DCF activation in circulating erythrocytes by approximately 10% following 10 days of stress exposure. Oral administration of F42 also significantly reduced DCF activation by approximately 10% in healthy human subjects undergoing exercise-induced oxidative stress. CONCLUSIONS: Oral administration of F42 in rodents produces transient reductions in stress hormones and reduces stress indicators following sub-chronic psychological stress exposure. In humans, F42 acts as an early and potent antioxidant capable of scavenging free radicals within 30 min of ingestion.

[Study on chemical constituents from Chloranthus multistachys].

To investigate the chemical constituents from the shoots of Chloranthus multistachys.All compounds wereisolated by using a combination of various chromatographic techniques including silica gel, ODS, Sephadex LH-20, reversed-phase HPLC, and other methods.Their structures were elucidated by the nuclear magnetic resonance (NMR), mass spectrometry, and other modernspectroscopies.As a result, 19 compounds were isolated from the shoots of C.multistachys and identified as zederoneepoxide(1), chlomultin C(2), curcolonol(3), sarcaglaboside A(4), zedoarofuran(5), (1E,4Z)-8-hydroxy-6-oxogermacra-1(10), 4,7(11)-trieno-12,8-lactone(6), chloranoside A(7), istanbulin A(8), (8α)-6,8-dihydroxycadina-7(11),10(15)-dien-12-oicacid-γ-lactone(9), codonolactone(10), lasianthuslactone A(11), 12,15-epoxy-5αH,9ßH-labda-8(17),13-dien-19-oicacid(12), 12R,15-dihydroxylabda-8(17),13E-dien-19-oicacid(13), N-transcinnamoyltyramine(14), trans-N-p-coumaroyltyramine(15), dibutyl phthalate (16), flavokawain A(17), bergenin(18), and enedione(19).Compounds 1, 2, 4, 7-10, 12-19 were isolated from C.multistachys for the first time and compounds 14-19 were obtained from the genus Chloranthus for the first time.

Insights into colour-tuning of chlorophyll optical response in green plants.

First-principles calculations within the framework of real-space time-dependent density functional theory have been performed for the complete chlorophyll (Chl) network of the light-harvesting complex from green plants, LHC-II. A local-dipole analysis method developed for this work has made possible the studies of the optical response of individual Chl molecules subjected to the influence of the remainder of the chromophore network. The spectra calculated using our real-space TDDFT method agree with previous suggestions that weak interaction with the protein microenvironment should produce only minor changes in the absorption spectrum of Chl chromophores in LHC-II. In addition, relative shifting of Chl absorption energies leads the stromal and lumenal sides of LHC-II to absorb in slightly different parts of the visible spectrum providing greater coverage of the available light frequencies. The site-specific alterations in Chl excitation energies support the existence of intrinsic energy transfer pathways within the LHC-II complex.

Effects of droplet-vitrification cryopreservation based on physiological and antioxidant enzyme activities of Brassidium shooting star orchid.

Protocorm-like bodies (PLBs) of Brassidium Shooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs of Brassidium Shooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.

Codonolactone, a sesquiterpene lactone isolated from Chloranthus henryi Hemsl, inhibits breast cancer cell invasion, migration and metastasis by downregulating the transcriptional activity of Runx2.

Metastasis is the most insidious aspect of breast cancer, but effective strategies to control this malignant process are still lacking. In previous studies, we screened over 200 extracts from plants of genus Chloranthaceae by bioactivity-guided fractionation, and found that Codonolactone (CLT) exhibited potential antimetastatic properties in breast cancer cells. This sesquiterpene lactone was isolated from Chloranthus henryi Hemsl, and is also found in other medical herbs, such as Codonopsis pilosula, Atractylodes macrocephala Koidz and others. Here, we report that CLT inhibited the ability of invasion and migration in metastatic breast cancer cells. Furthermore, CLT exhibited significant suppression on formation of lung metastatic foci of breast cancer in vivo. We next investigated the mechanism of CLT-induced metastasis inhibitory effects in breast cancer cells. A significant inhibition on activity and expression of MMP-9 and MMP-13 was observed. Moreover, data from western blotting, Runx2 transcription factor assay and chromatin immunoprecipitation assay showed that binding ability of Runx2 to sequences of the mmp-13 promoter was inhibited by CLT. Collectively, these findings suggested that the antimetastatic properties of CLT in breast cancer were due to the inhibition of MMPs, which might be associated with a downregulation of Runx2 transcriptional activity.

Global searches for microalgae and aquatic plants that can eliminate radioactive cesium, iodine and strontium from the radio-polluted aquatic environment: a bioremediation strategy.

The Fukushima 1 Nuclear Power Plant accident in March 2011 released an enormously high level of radionuclides into the environment, a total estimation of 6.3 × 10¹7 Bq represented by mainly radioactive Cs, Sr, and I. Because these radionuclides are biophilic, an urgent risk has arisen due to biological intake and subsequent food web contamination in the ecosystem. Thus, urgent elimination of radionuclides from the environment is necessary to prevent substantial radiopollution of organisms. In this study, we selected microalgae and aquatic plants that can efficiently eliminate these radionuclides from the environment. The ability of aquatic plants and algae was assessed by determining the elimination rate of radioactive Cs, Sr and I from culture medium and the accumulation capacity of radionuclides into single cells or whole bodies. Among 188 strains examined from microalgae, aquatic plants and unidentified algal species, we identified six, three and eight strains that can accumulate high levels of radioactive Cs, Sr and I from the medium, respectively. Notably, a novel eustigmatophycean unicellular algal strain, nak 9, showed the highest ability to eliminate radioactive Cs from the medium by cellular accumulation. Our results provide an important strategy for decreasing radiopollution in Fukushima area.

A unique protein phosphatase with kelch-like domains (PPKL) in Plasmodium modulates ookinete differentiation, motility and invasion.

Protein phosphorylation and dephosphorylation (catalysed by kinases and phosphatases, respectively) are post-translational modifications that play key roles in many eukaryotic signalling pathways, and are often deregulated in a number of pathological conditions in humans. In the malaria parasite Plasmodium, functional insights into its kinome have only recently been achieved, with over half being essential for blood stage development and another 14 kinases being essential for sexual development and mosquito transmission. However, functions for any of the plasmodial protein phosphatases are unknown. Here, we use reverse genetics in the rodent malaria model, Plasmodium berghei, to examine the role of a unique protein phosphatase containing kelch-like domains (termed PPKL) from a family related to Arabidopsis BSU1. Phylogenetic analysis confirmed that the family of BSU1-like proteins including PPKL is encoded in the genomes of land plants, green algae and alveolates, but not in other eukaryotic lineages. Furthermore, PPKL was observed in a distinct family, separate to the most closely-related phosphatase family, PP1. In our genetic approach, C-terminal GFP fusion with PPKL showed an active protein phosphatase preferentially expressed in female gametocytes and ookinetes. Deletion of the endogenous ppkl gene caused abnormal ookinete development and differentiation, and dissociated apical microtubules from the inner-membrane complex, generating an immotile phenotype and failure to invade the mosquito mid-gut epithelium. These observations were substantiated by changes in localisation of cytoskeletal tubulin and actin, and the micronemal protein CTRP in the knockout mutant as assessed by indirect immunofluorescence. Finally, increased mRNA expression of dozi, a RNA helicase vital to zygote development was observed in ppkl(-) mutants, with global phosphorylation studies of ookinete differentiation from 1.5-24 h post-fertilisation indicating major changes in the first hours of zygote development. Our work demonstrates a stage-specific essentiality of the unique PPKL enzyme, which modulates parasite differentiation, motility and transmission.

A survey of green plant tRNA 3'-end processing enzyme tRNase Zs, homologs of the candidate prostate cancer susceptibility protein ELAC2.

BACKGROUND: tRNase Z removes the 3'-trailer sequences from precursor tRNAs, which is an essential step preceding the addition of the CCA sequence. tRNase Z exists in the short (tRNase ZS) and long (tRNase ZL) forms. Based on the sequence characteristics, they can be divided into two major types: bacterial-type tRNase ZS and eukaryotic-type tRNase ZL, and one minor type, Thermotoga maritima (TM)-type tRNase ZS. The number of tRNase Zs is highly variable, with the largest number being identified experimentally in the flowering plant Arabidopsis thaliana. It is unknown whether multiple tRNase Zs found in A. thaliana is common to the plant kingdom. Also unknown is the extent of sequence and structural conservation among tRNase Zs from the plant kingdom. RESULTS: We report the identification and analysis of candidate tRNase Zs in 27 fully sequenced genomes of green plants, the great majority of which are flowering plants. It appears that green plants contain multiple distinct tRNase Zs predicted to reside in different subcellular compartments. Furthermore, while the bacterial-type tRNase ZSs are present only in basal land plants and green algae, the TM-type tRNase ZSs are widespread in green plants. The protein sequences of the TM-type tRNase ZSs identified in green plants are similar to those of the bacterial-type tRNase ZSs but have distinct features, including the TM-type flexible arm, the variant catalytic HEAT and HST motifs, and a lack of the PxKxRN motif involved in CCA anti-determination (inhibition of tRNase Z activity by CCA), which prevents tRNase Z cleavage of mature tRNAs. Examination of flowering plant chloroplast tRNA genes reveals that many of these genes encode partial CCA sequences. Based on our results and previous studies, we predict that the plant TM-type tRNase ZSs may not recognize the CCA sequence as an anti-determinant. CONCLUSIONS: Our findings substantially expand the current repertoire of the TM-type tRNase ZSs and hint at the possibility that these proteins may have been selected for their ability to process chloroplast pre-tRNAs with whole or partial CCA sequences. Our results also support the coevolution of tRNase Zs and tRNA 3'-trailer sequences in plants.