Analysis of the Prunellae Spica transcriptome under salt stress.

Prunella vulgaris L. is a moderately salt tolerant plant commonly found in China and Europe, whose spica (Prunellae Spica) has been used as a traditional medicine. The scant transcriptomic and genomic resources of Prunellae Spica have greatly hindered further exploration of the underlying salt tolerance mechanism of this species. To clarify the genetic basis of its salt tolerance, high-throughput sequencing of mRNAs was employed for de novo transcriptome assembly differential expression analysis of Prunellae Spica under salt stress. 118,664 unigenes were obtained by assembling pooled reads from all libraries with 68,119 sequences annotated. A total of 3857 unigenes were differentially expressed under low, medium and high salt stress, including 2456 up-regulated and 1401 down-regulated DEGs, respectively. Gene ontology analysis revealed that salt stress-related categories involving 'catalytic activity', 'binding', 'metabolic process' and 'cellular process' were highly enriched. KEGG pathway annotation showed that the DEGs from different salt stress treatment groups were mainly enriched in the pathways of translation, signal transduction, carbohydrate metabolism, energy metabolism, lipid metabolism and amino acid metabolism, accounting for over 60% of all DEGs. Finally, it showed that the results of quantitative real-time polymerase chain reaction (qRT-PCR) analysis for 10 unigenes that randomly selected were significantly consistent with RNA-seq data, which further assisted in the selection of salt stress-responsive candidate genes in Prunellae Spica. This study represents a significant step forward in understanding the salt tolerance mechanism of Prunellae Spica, and also provides a significant transcriptomic resource for future work.

An exploration of hypotheses that explain herbivore and pathogen attack in restored plant communities.

Many hypotheses address the associations of plant community composition with natural enemies, including: (i) plant species diversity may reduce enemy attack, (ii) attack may increase as host abundance increases, (iii) enemy spillover may lead to increased attack on one host species due to transmission from another host species, or enemy dilution may lead to reduced attack on a host that would otherwise have more attack, (iv) physical characteristics of the plant community may influence attack, and (v) plant vigor may affect attack. Restoration experiments with replicated plant communities provide an exceptional opportunity to explore these hypotheses. To explore the relative predictive strengths of these related hypotheses and to investigate the potential effect of several restoration site preparation techniques, we surveyed arthropod herbivore and fungal pathogen attack on the six most common native plant species in a restoration experiment. Multi-model inference revealed a weak but consistent negative correlation with pathogen attack and host diversity across the plant community, and no correlation between herbivory and host diversity. Our analyses also revealed host species-specific relationships between attack and abundance of the target host species, other native plant species, introduced plant species, and physical community characteristics. We found no relationship between enemy attack and plant vigor. We found minimal differences in plant community composition among several diverse site preparation techniques, and limited effects of site preparation techniques on attack. The strongest associations of community characteristics with attack varied among plant species with no community-wide patterns, suggesting that no single hypothesis successfully predicts the dominant community-wide trends in enemy attack.

Effects of ammonium to nitrate ratio on growth, nitrogen metabolism, photosynthetic efficiency and bioactive phytochemical production of Prunella vulgaris.

CONTEXT: Prunella vulgaris L (Labiatae) is commonly used as a traditional medicinal herb in some Asian and Europe countries. To date, few studies have been conducted to determine the influence of [Formula: see text] - N/[Formula: see text] - N ratio on growth, physiological development, and bioactive phytochemical accumulation in hydroponically grown P. vulgaris. OBJECTIVE: The current study was conducted to evaluate the effect of five [Formula: see text] - N/[Formula: see text] - N ratios on growth, nitrogen metabolism, photosynthetic efficiency, and bioactive phytochemical production in P. vulgaris. MATERIALS AND METHODS: Hydroponically cultivated P. vulgaris were fertilized with five [Formula: see text] - N/[Formula: see text] - N ratios in a greenhouse for 85 d. Dried weight of root, stem, leaf and spica, leaf area, photosynthetic efficiency, activities of nitrate reductase (NR), glutamine synthetase (GS), and the concentrations of N, soluble protein, and free amino acids in the leaves, as well as the contents of rosmarinic acid (RA), ursolic acid (UA), and oleanolic acid (OA) in the spicas were measured. RESULTS: Both [Formula: see text] - N and [Formula: see text] - N as the sole source of nitrogen had inhibitory effects on P. vulgaris growth. P. vulgaris fertilized with the 25/75 ([Formula: see text] - N/NO3 - N) ratio had the highest leaf area, photosynthetic rate, and chlorophyll content. The 25/75 ([Formula: see text]/[Formula: see text]) ratio increased the spica biomass by 1828%, nitrate-reductase (NR) activity by 98%, and soluble protein concentration by 29.45% compared with the 100/0 ([Formula: see text]/[Formula: see text]) treatment. Additionally, 25 [Formula: see text] - N/75 NO3 - N resulted in the highest contents of RA and total flavonoids as well as relatively high contents of UA and OA; therefore, this ratio had the highest yield of RA, UA, OA, and total flavonoids in spicas. DISCUSSION AND CONCLUSION: The use of 25 [Formula: see text] - N/75 [Formula: see text] - N is recommended to improve biomass production and medicinal quality of P. vulgaris.

[Identification of chemical signals and haustorium induced of Thesium chinense].

To separate and identify chemical signals which induce Thesium chinense haustorium formation, the components of T. chinense roots secretion collected with XAD-4 resin were detected by GC-MS. The effect of DMBQ as exogenous signals to induce haustorium formation in T. chinense was studied. Fifty-three compounds of 9 types had been detected, including hydrocarbons, esters, organic acids, ketones, alcohols, nitrogen containing compounds, phenolic acids, aldehyde and quinine. It is worth noting that the 2, 5-di-tert-butyl-1,4-benzoquinone has the core structure of 1,4-benzoquinone, which may play an important role in the parasitic relationship of Prunella vulgaris and T. chinense: DMBQ worked effectively on inducing haustoria, but induction effects vary widely in different concentrations. DMBQ with the concentration of 1 µmol x L(-1) showed the best effect of the inducing ability with a ratio of 110.52 when treated to induce haustoria.

[Observations of in vitro pollen germination of Prunella vulgaris].

To determine the optimal condition of pollen germination. The pollen of Prunella vulgaris was cultured in vitro. Pollen germination rates were recorded using 10% H3BO4, 30% Ca(NO3)2, 20% MgSO4 and 10% KNO3 as the basic mineral medium with PEG of different molecular weight, sucrose of various density and multiple pH value. The rates were also measured under different cultivation temperature and pollen acquisition time. The optimal condition of pollen germination is 10% H3 BO4, 30% Ca(NO3)2, 20% MgSO4, 10% KNO3, and 25% PEG-4000 as the medium, with pH about 6. 5 and pollen acquired at the beginning of blossom.

Optimisation of potassium chloride nutrition for proper growth, physiological development and bioactive component production in Prunella vulgaris L.

Prunella vulgaris L. is an important medicinal plant with a variety of pharmacological activities, but limited information is available about its response to potassium chloride (KCl) supplementation. P. vulgaris seedlings were cultured in media with four different KCl levels (0, 1.00, 6.00 and 40.00 mM). Characteristics relating to the growth, foliar potassium, water and chlorophyll content, photosynthesis, transpiration, nitrogen metabolism, bioactive constituent concentrations and yield were determined after three months. The appropriate KCl concentration was 6.00 mM to result in the highest values for dry weight, shoot height, spica and root weight, spica length and number in P. vulgaris. The optimum KCl concentration resulted in a maximum net photosynthetic rate (Pn) that could be associated with the highest chlorophyll content and fully open stomata conductance. A supply of surplus KCl resulted in a higher concentration of foliar potassium and negatively correlated with the biomass. Plants that were treated with the appropriate KCl level showed a greater capacity for nitrate assimilation. The Pn was significantly and positively correlated with nitrate reductase (NR) and glutamine synthetase (GS) activities and was positively correlated with leaf-soluble protein and free amino acid (FAA) contents. Both KCl starvation (0 mM) and high KCl (40.00 mM) led to water loss through a high transpiration rate and low water absorption, respectively, and resulted in increased concentrations of ursolic acid (UA), oleanolic acid (OA) and flavonoids, with the exception of rosmarinic acid (RA). Moreover, the optimum concentration of KCl significantly increased the yields of RA, UA, OA and flavonoids. Our findings suggested that significantly higher plant biomass; chlorophyll content; Pn; stronger nitrogen anabolism; lower RA, UA, OA and flavonoid accumulation; and greater RA, UA, OA and flavonoid yields in P. vulgaris could be expected in the presence of the appropriate KCl concentration (6.00 mM).

Biochar mitigates negative effects of salt additions on two herbaceous plant species.

Addition of pyrolyzed biomass ("biochar") to soils has commonly been shown to increase crop yields and alleviate plant stresses associated with drought and exposure to toxic materials. Here we investigate the ability of biochar (at two dosages: 5 and 50 t ha(-1)) to mitigate salt-induced stress, simulating road salt additions in a factorial glasshouse experiment involving the broadleaved herbaceous plants Abutilon theophrasti and Prunella vulgaris. Salt additions of 30 g m(-2) NaCl to unamended soils resulted in high mortality rates for both species. Biochar (Fagus grandifolia sawdust pyrolyzed at 378 °C), when applied at 50 t ha(-1) as a top dressing, completely alleviated salt-induced mortality in A. theophrasti and prolonged survival of P. vulgaris. Surviving A. theophrasti plants that received both 50 t ha(-1) biochar and salt addition treatments showed growth rates and physiological performance similar to plants without salt addition. Biochar treatments alone also substantially increased biomass of P. vulgaris, with a ∼50% increase relative to untreated controls at both biochar dosages. Biochar did not significantly affect photosynthetic carbon gain (Amax), water use efficiency, or chlorophyll fluorescence (Fv/Fm) in either species. Our results indicate that biochar can ameliorate salt stress effects on plants through salt sorption, suggesting novel applications of biochar to mitigate effects of salinization in agricultural, urban, and contaminated soils.

[Preliminary study on breeding system of Prunella vulgaris].

The research was conducted to study the breeding system of Prunella vulgaris L. Flowering dynamics was observed. Pollen viability, stigma receptivity, pollen-ovule ratio (P/O), out-crossing index (OCI) were measured. Bagging experiments were conducted. The results showed that the life span of one single flower was 1-2 days, the flowering span for the inflorescence of stalk was 7-14 days, the P/O was 1 046+/-148. 26, the OCI was 2. Combined with results of bagging experiment, the breeding system of P. vulgaris L. was mixed with cross-polination and self pollination. In the absence of pollination insects, the pollination and fertilization can be accomplished with high seed setting rate, and the seeds have a relatively high germination rate.

Soil fertilization leads to a decline in between-samples variability of microbial community δ13C profiles in a grassland fertilization experiment.

Gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure the (13)C/(12)C ratios of PLFAs at natural abundance levels from a temperate grassland nitrogen (N) and phosphorus (P) factorial fertilization experiment in northern Greece. In each plot two rhizosphere samples were derived centred around individual Agrostis capillaris and Prunella vulgaris plants. It was hypothesized that the isotopic signal of microbes that preferentially feed on recalcitrant litter such as fungi would be modified by fertilization more strongly than that of opportunistic microbes using labile C. Microbial community δ(13)C was affected by both P and N fertilization regime and plant species identity. However, we have been unable to detect significant nutrient effects on individual groups of microbes when analyzed separately in contrast to our original hypothesis. Intra-treatment variability, as evaluated from Hartley's F(max) tests in the five first PCA components axes as well as the size of the convex hulls in PCA scoreplots and Mahalanobis distances, was considerably higher in the non-fertilized controls. Moreover, a significant relationship was established between the change in PLFA abundances and their respective changes in δ(13)C for the aggregate of samples and those simultaneously fertilized with N and P. We conclude that use of compound specific isotope analysis in the absence of labelling represents a valuable and overlooked tool in obtaining an insight of microbial community functioning.

[Research on callus induction and plantlet regeneration of Prunella vulgaris].

OBJECTIVE: To study the conditions of callus induction and plantlet regeneration of Prunella vulgaris. METHOD: By using the orthogonal experiment design, different explants, sucrose, plant growth substances and their ratio for callus induction and differentiation were optimized. RESULT AND CONCLUSION: The inductivity of leaves was the highest, followed by stems, but callus of the leafstalks could not be induced. The main factor of affecting the formation of callus was 6-BA. The optimal medium for callus induction was MS + 6-BA 3.0 mg x L(-1) + NAA 0.1 mg x L(-1) + 2,4-D 0.5 mg x L(-1) + sucrose 3%. The optimal medium for callus differentiation was 1/2 MS + 6-BA 3.25 mg x L(-1) + NAA 1.25 mg x L(-1) + sucrose 2%. The optimal medium for rooting was MS + IBA 1.0 mg x L(-1) + sucrose 3%.

Testing spatial theories of plant coexistence: no consistent differences in intra- and interspecific interaction distances.

Plants stand still and interact with their immediate neighbors. Theory has shown that the distances over which these interactions occur may have important consequences for population and community dynamics. In particular, if intraspecific competition occurs over longer distances than interspecific competition (heteromyopia), coexistence can be promoted. We examined how intraspecific and interspecific competition scales with neighbor distance in a target-neighbor greenhouse competition experiment. Individuals from co-occurring forbs from calcareous grasslands were grown in isolation and with single conspecific or heterospecific neighbors at distances of 5, 10, or 15 cm (Plantago lanceolata vs. Plantago media and Hieracium pilosella vs. Prunella grandiflora). Neighbor effects were strong and declined with distance. Interaction distances varied greatly within and between species, but we found no evidence for heteromyopia. Instead, neighbor identity effects were mostly explained by relative size differences between target and neighbor. We found a complex interaction between final neighbor size and identity such that neighbor identity may become important only as the neighbor becomes very large compared with the target individual. Our results suggest that species-specific size differences between neighboring individuals determine both the strength of competitive interactions and the distance over which these interactions occur.

[Effect of water stress on physiological and growth charaters of Prunella vulgaris at the vegetative stage].

OBJECTIVE: To study the effect of water stress on physiological and the growth characters of Prunella vulgaris at the vegetative stage. METHOD: The plants were treated timely and quantitatively by weighting method, and the relevant index were measured under different water stress conditions. RESULT: With the long time of water stress, the plants of SY2 and SY3 showed the quickest growth rate and the best of growth vigor. The protective enzyme and osmoregulation substance presented the trend of increase firstly and then decrease. Under the same time of water stress, with the increase of extent in treatment, the protective enzyme and osmoregulation substance presented the trend of increase firstly and then decrease, and SY2 and SY3 were the lowest. CONCLUSION: The protective enzyme and osmoregulation substance of P. vulgaris have a whole effect. The suitable water range of growth in P. vulgaris is 65%-80%.

[Effects of seed priming on drought tolerence in Prunella vulgaris].

OBJECTIVE: To explore an effective way to increase drought tolerance of Prunella vulgaris seed. METHOD: The treatment of drought stress to P. vulgaris seeds was made by the different concentrations of PEG solutions. Primed seeds germinated under 25% PEG. RESULT: As concentrations of PEG increasing, seed germination percentage, germination index and vitality index reduced. Primed with 20%-25% PEG, 300-500 mg x L(-1) GA3 and 1.6%-2.0% KNO3-KH2PO4 could enhance three population seeds germination index and vitality index under drought stress. Treated with NaCl, seeds germination percentage and germination index of two population increased, which came from Nanjing Zijinshan and Anhui Jinzhai, respectively, while those of seeds from Gansu Chengxian reduced. CONCLUSION: Treated with PEG, GA3, KNO3-KH2 PO4 under proper concentration, seed vigor, seed resistance under drought stress would increase.

[Study on seed quality test and quality standard of Prunella vulgaris].

OBJECTIVE: To study seed quality test, and establish seed quality classification standard of Prunella vulgaris. METHOD: The seed quality and planting quality of P. vulgaris from different population were measured and these indexes were analyzed by K-clustering. RESULT AND CONCLUSION: The seed purity, 1000 seeds weight, seed moisture content, seed viability of the seed of P. vulgaris from different population were measured, and the seed quality classification standard of P. vulgaris.

[Effects of seed priming on salt tolerance in Prunella vulgaris seed germination under saline conditions].

OBJECTIVE: Selecting an effective way to increase salt-resistance of Prunella vulgaris seed through seed priming technology. METHOD: The treatment of salt stress to P. vulgaris seeds was made by the different concentrations of NaCl solutions. Primed seeds germinated under 0.8% NaCl. RESULT: As concentrations of NaCl increasing, seed germination percentage, germination index and vitality index reduced. Primed with 15%-35% PEG, 100-500 mg x L(-1) GA3 and 0.4%-2.0% KNO3-KH2PO4 could enhance seeds germination index and vitality index under salt stress while treated with NaCl seeds germination percentage reduced. CONCLUSION: Treated with PEG, GA3, KNO3-KH2PO4 under proper concentration, the seed vigor, seed resistance under salt stress increased.

[Effects of seed priming on vigor of Prunella vulgaris seeds].

OBJECTIVE: To select an effective way to enhance vigor of Prunella vulgaris seeds. METHOD: Three population seeds were treated at the 20 degrees C and dark enviroment. RESULT: Priming with 20% - 30% PEG and 200 - 400 mg x L(-1) GA3 could enhance seeds germination and vigor. Germination percentage of three population seeds treated with 0. 6% - 3.0% NaCl reduced, but they started to germinate in advance. Treated with 0.6% - 2.4% KNO3-KH2PO4, germination rate and vigor of seeds in Zijinshan and Pan' an both increased and the one in Bozhou decreased. CONCLUSION: Vigor of P. vulgaris seed treated with PEG and GA3 under proper concentration increases, while treated with KNO3-KH2PO, and NaCl low vigor seeds germination rate reduces.

[Considerations for the treatment of chronic fatigue syndrome].

The etiology of chronic fatigue syndrome(CFS) is still unknown and under active discussion, but involvement of psychosocial factors appear to be essential for the onset and clinical course of CFS. As CFS patients complain of many stress-related physical and psychological symptom, it is important to understand the CFS from psychosomatic point of view. Not only for the pharmaceutical treatment, attentive consideration is required for treatment of exhaustion of body and mind of CFS patients. Use of anti-depressants or oriental herb medicine is often effective to relieve the anxiety and depressive condition. Furthermore to augment the self-healing potential, psychosomatic approach is important to modify the life style and behavioral characteristics.

Microgametophyte population sizes and plant reproductive output in the insect-pollinated Prunella grandiflora (Lamiaceae).

Intraspecific variation in pollen deposition and number of pollen tubes per style is rarely quantified, but is essential for assessing the occurrence of pollen limitation and pollen competition and their evolutionary implications. Moreover, pollen deposition, pollen tube growth, and the fate of fertilized ovules are rarely distinguished in field studies. Here we present such a study in eight natural populations of Prunella grandiflora. We quantified microgametophyte population sizes and inferred pollen limitation when the number of fertilizable ovules exceeded pollen tubes, and assessed seed set and fate after open pollination. Two and three populations had on average significantly fewer pollen grains and pollen tubes per flower, respectively, than the fixed number of fertilizable ovules per fruit, while one population experienced significant pollen competition. Style length was positively correlated with the number of pollen tubes. While pollen availability was very variable, seed abortion was significantly less frequent in denser populations, and in one population the proportion of well-developed seeds was significantly, positively correlated with the number of pollen tubes in the style. Less pollen deposition, lower numbers of pollen tubes reaching the base of the style, lower pollen quality and therefore increased abortion of fertilized ovules can all reduce seed set in natural P. grandiflora stands. Substantial intraspecific variability implies that microgametophyte competition also occurs in this species. Finally, style morphology may affect pollen receipt.