Platycodon grandifloras polysaccharides inhibit mitophagy injury induced by Cr (VI) in DF-1 cells.

This study aimed to investigate the role of Platycodon grandiflorus polysaccharide (PGPS) in chromium (VI)-induced autophagy in a chicken embryo fibroblast cell lines (DF-1 cells). DF-1 cells were exposed to Cr (VI), PGPSt, and Cr (VI) + PGPSt, and their effects on cell viability, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and autophagy-related proteins were examined. The results showed that the cell viability was reduced after Cr (VI) treatment, and 3-MA, CsA or PGPSt suppressed this decrease. Cr (VI) treatment increased the ROS levels and decreased the MMP, thereby enhancing the expression of mitochondrial autophagy marker proteins (PINK1, Parkin, and LC3-II), inhibiting mitophagy autophagy protein TOMM20 expression, and promoting the degradation of autophagy-related marker p62. These changes led to exceeding mitochondrial autophagy and cell trauma and could be mitigated by PGPSt. Overall, our research showed that Cr (VI) can induce exceeding mitochondrial autophagy in DF-1 cells, whereas PGPSt can improve Cr (VI)-induced mitochondrial autophagy by inhibiting ROS and restoring MMP.

Assessment of Platycodon grandiflorum germplasm resources from northern Anhui province based on ISSR analysis.

Based on genetic diversity analysis with ISSR-PCR, this study was to access the germplasm resources of Platycodon grandiflorum in northern Anhui province. Ten primers that could produce more distinct and repeatable bands were used for ISSR-PCR. Statistic analysis was conducted by POPGENE v. 1.32, Arlequin3.l, NTSYS-pc version 2.1. (1) Seventy-four polymorphic bands (76.29 %) out of a total of 97 were generated from 105 individuals in five populations. (2) Shannon index of diversity ranged from 0.307 to 0.260, diversity at species level was 0.3581, which means superior genetic diversity. (3) Genetic diversity across all the populations revealed by AMOVA indicated that 86.02 % occurred within populations. (4) The Fst value was 0.1398, indicating a intermediate genetic differentiation among populations. (5) Dendrogram relationship illustrated genetic distance was correlated with geographic distance. ISSR markers can be used for studying genetic diversity of P. grandiflorum. Degradation of populations doesn't happen in northern Anhui province, bank of germplasm preservation should be established for cultivation of excellent variety of P. grandiflorum.

[Preliminary study on the effect of climate factors on pollen fertility in Platycodon grandiflorum].

OBJECTIVE: To have a better utilization of male sterile lines in heterozygotic breeding of Platycodon grandiflorum and provide theoretical basis for Platycodon grandiflorum hyboridization. METHODS: The pollen viability was detected by the means of aceto carmine dyeing, and the correlation analysis between climate factors of each anther development stage and pollen viability was estimated by Pearson coefficients. RESULTS: Pollen viability variation range of male-sterile line GP1BC1-12 was 0% - 27%. That of male-sterile line GP12BC4-10 and chifeng germplasm was respectively 1.3% - 17.9% and 75.9% - 98.5%. Further linear regression analysis between climate factors of each anther development stage and pollen viability indicated that the degree of sensitivity varied with different germplasm of Platycodon grandiflorum. Among three germplasm, male sterile line GP12BC4-10 was the most stable one to the climate factors, and the male-sterile line GP1BC1-12 was the most sensitive one. CONCLUSION: Temperature and solar irradiation are the most important climate factors to affect pollen viability in Platycodon grandflorum, and microspore mother cells stage (MMC) is its sensetive stage.

[Effect of seed soaking with aluminum on seed germination and seedling physiology of Platycodon grandiflorum].

In order to study the effect of seed soaking with different aluminum solution on seed germination and seedling physiological characteristics of Platycondon grandiflorum, two P. grandiflorum varieties'seed (the white flower and the purple flower) were soaked in Al3+ solution with different concentrations (0, 10, 100, 250, 500, 750 and 1000 mg x L) for 24 h, then germinated in illumination incubator. Results showed that the aluminum toxicity on the trends of the germination rate, germination index and vigor index was positive associated with its concentration, and the Al tolerance of the purple was slightly greater than that of the white. There were some relationships between the physiological indices, which were the leakage rate of electrolyte, the malonaldehyde (MDA) content, the activities of peroxidase (POD) and superoxide dismutase (SOD) , the free praline(Pro) and the soluble sugar contents, with the concentrations of Al. It was suggested that there was Al tolerance difference between the two P. grandiflorum varieties: the purple flower was greater than the white.

[Study on seed quality test and quality standard of Platycodon grandiflorum].

OBJECTIVE: To study quality test, and establish quality classification standard of Platycodon grandiflorum. METHOD: The seed quality and planting quality of P. grandiflorum from different producing areas and in different growing years were measured. RESULT AND CONCLUSION: The range of seed purity, weight per 1000 seeds, seed moisture content,seed viability were determined and the primary seed quality classification standard was established.

[Studies on germination characteristics of Platycodon grandiflorum seed].

OBJECTIVE: To find out the optimal condition for the germination by studying the effects of light, temperature, seed soaking and cultivation condition on Platycodon grandiflourm, and offer the basis for standardized culture of P. grandflorum. METHOD: The rate of water absorption of the seed was determined. The germination of P. grandiflorum seed was tested under following conditions: treatments under different temperature (10,15,20,25,30 degrees C), light treatments (light and dark), seed soaking time (12,24,36 h) and different germination cultivation conditions (on filter paper, between filter paper, between gauze,on gauze). RESULT: The water absorption of the seeds reached the maximal 120% within 36 h at 25 degrees C. The time of seeds soaking had limited effect on the germination of the seed, while temperature and light condition showed significant effects on the germination. CONCLUSION: The optimal condition for the germination of the seed of P. grandiflorum is as follow:seed soaking for 12 h, and 25 degrees C underlight.

[Influence of exogenous substance on germination of Platycodon grandiflorum seeds].

OBJECTIVE: To study of exogenous substances on the germination rate of Platycodon grandiflorum and offer the basis for the standardized culture of P. grandiflorum. METHOD: At 25 degrees C, under darkness and lightness, do pretreatmeats on seeds by using GA3, H2O2, KMnO4, PEG at different concentrations. RESULT: The results indicated that the pretreatments with GA3 at a concentrating of 50-250 mg x L(-1) and 1%-2% of H2O2 could increase germination of P. grandiflorum seed at a certain degree. Contrariwise 0.1%-0.5% of KMnO4 and 15%-35% of PEG inhibited the germination. CONCLUSION: Pretreatment with 50-250 mg x L(-1)GA3 and H2O2 at a low cencontration could increase the seed germination of P. grandiflorum.

[Study on the stigma/pollen vigor and self-compatibility of Platycodon grandiflorum].

OBJECTIVE: To provide the basal data for the breeding and cultivation of Platycodon grandiflorum. METHOD: The field investigation and pollination by bagging were carried out. TTC(2,3,5-triphenyl tetrazolium chloride) solution was used to test the pollen vigor. RESULT: The stigma life-span of P. grandiflorum was about 9 days, however the optimal time for pollination is 4-6 days after the petals opening, with the stigma was splitting lightly or significantly. When the petals opened, the anther began scattering pollen, and finished in the same day. The pollen vigor was about 81.4% at the beginning, and decreases to 27.6% three days later. The pollen vigor still remains 64.4% three days later, when the flower was kept in the desiccant. The natural fructification rate of self-flower-pollination was 4.8%. The fructification rate and compatible index was about 62.7% and 54.6, respectively, when the self-plant-pollination performed by hand. They decreased to 12.8% and 6.5 when the pollination was implemented during the flowering period. CONCLUSION: Low fructification percentage of self-flower-pollination attributes to the difference of maturing period of pistil and stamen, as well as the short pollen life-span of P. grandiflorum. The compatibility of self-plant-pollination is high during flowering period when pollination performed by hand. The life-span of the pollen can be prolonged significantly when keeping in the dry environment.