A comparative study of the dynamic accumulation of polyphenol components and the changes in their antioxidant activities in diploid and tetraploid Lonicera japonica.

Polyploidization is an effective method to achieve a higher yield of secondary metabolism active ingredients in medicinal plants. Polyphenols are the main active substances that contribute to the antioxidant activity of Lonicera japonica. For studying on the effect of chromosome doubling and harvest time on the dynamic accumulation of the main active substances and antioxidant capabilities of L. japonica, the polyphenol composition contents (7 phenolic acids and 3 flavonoids) and the antioxidant capacity in buds and flowers of diploid and tetraploid L. japonica at six different growth stages were determined by HPLC-DAD and three common antioxidant assays (FRAP, OH RSC and DPPH ARP), and the correlation between the dynamic accumulation of the polyphenol components and antioxidant capacity was also analyzed in current research. The results indicated that the content of the most determined phenolic acids and flavonoids and the antioxidant capacity in most of the growth stages from tetraploid plants were significantly higher than those in the diploid plants. Furthermore, the changes in the antioxidant activity presented a significant positive correlation with the variations in the chlorogenic acid, rutin, hyperoside, luteoloside in the two ploidy levels of L. japonica plants. The higher yields of chlorogenic acid (158.97, 164.00, 199.85 mg), luteoloside (5.44, 4.03, 6.31 mg), hyperoside (1.15, 1.06, 1.30 mg) and total flavonoids (9.87, 8.67, 11.10 mg) from 100 buds or flowers in tetraploid plants occurred during the S3-S5 stages, and these stages also exhibited higher antioxidant activities. Therefore, the stages of S3-S5 are recommended as the best time for harvesting high-yield, high-quality tetraploid Flos Lonicerae Japonicae.

Antioxidant capacities and anthocyanin characteristics of the black-red wild berries obtained in Northeast China.

Various edible berries widely accessible in nature in Northeast China are poorly exploited. The compositions and contents of anthocyanins in black (Padus maackii, Padus avium, Lonicera caerulea, and Ribes nigrum) and red (Ribes rubrum, Sambucus williamsii, Rubus idaeus, and Ribes procumbens) wild berries in Northeast China were firstly characterized by HPLC-DAD/ESI-MS(2). Twenty-three anthocyanins were detected and identified. Cyanidin glycosides were dominant in both berries. Six anthocyanins were reported for the first time in P. avium, R. rubrum, and Sambucus. Total anthocyanin content (TAC) ranged from 10mg/100gfreshweight (FW) (R. procumbens) to 1058mg/100gFW (P. maackii) among berries. The TACs and antioxidant activities assessed by DPPH and FRAP assays were much higher in black than in red berries. Black-red berries, especially P. maackii and P. avium, can be used in developing functional foods and in improving breeding programs.

Screening and characterization of endophytic Bacillus and Paenibacillus strains from medicinal plant Lonicera japonica for use as potential plant growth promoters

Abstract A total of 48 endophytic bacteria were isolated from surface-sterilized tissues of the medicinal plant Lonicera japonica, which is grown in eastern China; six strains were selected for further study based on their potential ability to promote plant growth in vitro (siderophore and indoleacetic acid production). The bacteria were characterized by phylogenetically analyzing their 16S rRNA gene similarity, by examining their effect on the mycelial development of pathogenic fungi, by testing their potential plant growth-promoting characteristics, and by measuring wheat growth parameters after inoculation. Results showed that the number of endophytic bacteria in L. japonica varied among different tissues, but it remained relatively stable in the same tissues from four different plantation locations. Among the three endophytic strains, strains 122 and 124 both had high siderophore production, with the latter showing the highest phosphate solubilization activity (45.6 mg/L) and aminocyclopropane-1-carboxylic acid deaminase activity (47.3 nmol/mg/h). Strain 170 had the highest indoleacetic acid (IAA) production (49.2 mg/L) and cellulase and pectinase activities. After inoculation, most of the six selected isolates showed a strong capacity to promote wheat growth. Compared with the controls, the increase in the shoot length, root length, fresh weight, dry weight, and chlorophyll content was most remarkable in wheat seedlings inoculated with strain 130. The positive correlation between enzyme (cellulose and pectinase) activity and inhibition rate on Fusarium oxysporum, the IAA production, and the root length of wheat seedlings inoculated with each tested endophytic strain was significant in regression analysis. Deformity of pathogenic fungal mycelia was observed under a microscope after the interaction with the endophytic isolates. Such deformity may be directly related to the production of hydrolytic bacterial enzymes (cellulose and pectinase). The six endophytic bacterial strains were identified to be Paenibacillus and Bacillus strains based on the results of 16S rRNA gene sequencing analysis and their physiological and biochemical characteristics. Results indicate the promising application of endophytic bacteria to the biological control of pathogenic fungi and the improvement of wheat crop growth.

[Hormesis effect of cadmium on Lonicera japonica].

A hydroponic experiment was conducted to study the growth characteristics of Lonicera japonica under the stress of different concentrations (0, 0.5, 2.5, 5, 10, and 25 mg L-1 ) cadmium (Cd), aimed to explore the hormesis effect of low concentrations Cd on L. japonica. At < or =5 mg L-1 of Cd, the maximum root length, plant dry biomass, and the contents of chlorophyll a, chlorophyll b, and carotenoid of L. japonica increased significantly, with the increment being 13. 6%, 11.7%, 14. 0% ,10. 8%, and 54. 5%, respectively, as compared with the control. <5 mg L-1 of Cd also had a definite positive effect on the leaf water content. At> or = 10 mg L-1 of Cd, the growth of L. japonica was inhibited significantly. When exposed to 25 mg L-1 of Cd, the shoot Cd concentration of L. japonica reached 622. 93 mg kg-1 , suggesting that L. japonica had a strong capacity of Cd-hyperaccumulation. The dose range of the hormesis effect of Cd on L. japonica was 0.5-5 mg L-1 of Cd.

Effects of cadmium hyperaccumulation on the concentrations of four trace elements in Lonicera japonica Thunb.

Hyperaccumulators are important in the phytoremediation of cadmium (Cd)-contaminated soil. In this study, Cd accumulation and the interactions between Cd and four other trace elements (Fe, Mn, Cu, and Zn) in Lonicera japonica Thunb. were investigated. As a result of exposure to soil containing 50 mg kg(-1) Cd, stem and shoot Cd concentrations reached 344.49 ± 0.71 and 286.12 ± 9.38 µg g(-1) DW respectively, without showing symptoms of visible damage to the plants. This suggests that L. japonica has a strong tolerance to Cd. It is proposed that trace metal elements are involved in the Cd-detoxification mechanisms shown by hyperaccumulators. There is a synergistic interaction in accumulation and translocation between Cd and Fe and a significantly negative correlation between Cd and Cu or Zn concentrations in L. japonica plant tissues. The imbalanced trace element concentrations influences detoxification processes to Cd, therefore, L. japonica could be considered as a new Cd-hyperaccumulator model to investigate the metal tolerance strategies of plants.

[Effects of cadmium stress on the growth and physiological characteristics of Lonicera japonica].

By using hydroponics, the growth and physiological characteristics of Lonicera japonica at different concentrations (0, 5, 10, 25, and 50 mg x L(-1)) of cadmium (Cd) were studied. The results showed that compared with the control, Cd stress had lesser effects on the growth of L. japonica. Within the range of test Cd concentrations, L. japonica biomass had less difference (P > 0.05) with the control, and at low concentration of Cd (5 mg x L(-1)), the total biomass and the biomasses of leaf and root were increased by 1.25%, 2.88 and 2.33%, respectively, illustrating that L. japonica had stronger resistance against Cd. Under low concentration Cd stress, the water content and soluble protein content in plant organs had some decrease, while the malondialdehyde (MDA) content in root and leaf increased by 51.90% and 23.07%, respectively, leaf chlorophyll and carotenoid contents increased by 15.87% and 24.89%, respectively, and superoxide dismutase (SOD) activity increased significantly. With increasing Cd concentration, the chlorophyll and carotenoid contents and SOD activity decreased to some extent.

Accumulation and tolerance characteristics of cadmium in a potential hyperaccumulator--Lonicera japonica Thunb.

Phytoremediation using hyperaccumulators is a promising technique of removing soil pollutants. In the study, growth responses, cadmium (Cd) accumulation capability and physiological mechanisms of Lonicera japonica Thunb. under Cd stress were investigated. Exposed to 5 and 10 mg L(-1) Cd, the plants did not show any visual symptoms, furthermore, the height, dry biomass of leaves, roots and total and the chlorophyll (CHL) content were obtained different grade increase. When the concentration of Cd was up to 50 mg L(-1), the height, dry biomass of leaves and roots had not significant differences compared with the control. The indexes of tolerance (IT) were all above 0.8. The maintenance of high superoxide dismutase (SOD) and catalase (CAT) activities was observed along with the increased Cd concentration, suggesting strong internal detoxification mechanisms inside plant cells. After 21 days exposure to 25 mg L(-1) Cd, stem and shoot Cd concentrations reached 344.49+/-0.71 and 286.12+/-9.38 microg g(-1) DW, respectively and the plant had higher bioaccumulation coefficient (BC) and translocation factor (TF). According to these results, it was shown L. japonica had strong tolerance and accumulation capability to Cd, therefore it is a potential Cd-hyperaccumulator.

[Impact of soil cadmium contamination on chlorophyll fluorescence characters and biomass accumulation of four broad-leaved tree species seedlings].

In a greenhouse pot experiment,a gradient of soil Cd concentration was established by adding 0,50,100 and 200 mg CdCl2 x kg(-1) air-dried soil, and the seedlings of one-year-old Rosa davurica, Philadelphus schrenkii, Acer mandshurica and Lonicera maackii were transplanted. The measurement of the seedlings' chlorophyll fluorescence parameters and biomass accumulation after 70 days of transplanting showed that with increasing soil Cd content, all the test tree species had a decrease of Fv/Fm, phi(PSII), qP and biomass, but an increase of qN. A. mandshurica had the greatest responses, followed by P. schrenkii and L. maackii, and R. davurica. The tolerance of these tree species to soil Cd contamination followed the order of R. davurica > P. schrenkii and L. maackii > A. mandshurica.