Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedl...Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedlings of Guisangyou 12 were used as the materials and the comparative experiment on subculture multi-plication and root induction used different kinds,concentrations and combinations of exogenous hormones. [Result] The hormone combination of 0.1 mg/L IBA＋1.5 mg/L 6-BA＋0.03 mg/L TDZ showed the best effects to bud multiplication, and the multiple of bud multiplication was 5.28. The effects of NAA was better than IBA and IAA on root induction. The hormone combination of 2.0 mg/L NAA＋1.0 mg/L PP333 was most suitable to the root induction, in which the rooting rate arrived to 100%, the root number was 7.01 and the root length was 1.38 cm on average. [Conclusion] The results wil provide some technical reference for large-scale propagation of mul-berry seedlings in vitro.展开更多
Drought at the grain filling stage of wheat will cause premature leaf senescence, thus leading to considerable loss of wheat yield. Therefore, this paper aims to establish a cultivation technology for strong drought r...Drought at the grain filling stage of wheat will cause premature leaf senescence, thus leading to considerable loss of wheat yield. Therefore, this paper aims to establish a cultivation technology for strong drought resistance, delayed senescence, and yield improvement based on the analysis of hormones homeostasis obtained by applying chemical control substances. Experiments were conducted with two genotypes of wheat. Four water irrigation treatments were applied to impose the water deficit, including well-watered control treatment(WW), mild water deficit(MiWD), moderate water deficit(MoWD), and severe water deficit(SWD). Exogenous abscisic acid(ABA) was sprayed on the plants at the anthesis stage of the wheat. As a result, exogenous ABA reduced initial senescence rate(r0), total duration of chlorophyll(Chltotal), rapid senescence phase(Chlloss), and the accumulated temperature at an inflection point(M) but improved the persistence phase(Chlper) of flag leaves under all of the four treatments. However, exogenous ABA produced inconsistent effects on photoassimilate relocation and grain weight under different treatments. It produced positive regulatory effects on grain weight under WW, MiWD, and MoWD treatments. On the one hand, spraying ABA during the persistence phase of flag leaves reduced the ratios of zeatin to gibberellin(Z/GA3), spermine to spermidine(Spm/Spd), and salicylic acid to ABA(SA/ABA),which prolonged active photosynthesis by stimulating high level of proline(Pro) and increased the activities of antioxidant enzymes, such as superoxide dismutase(SOD), peroxidase(POD), catalase(CAT), and ascorbate peroxidase(APX). Therefore, drought tolerance was enhanced, and more photosynthetic assimilates were accumulated. On the other hand, the rapid senescence phase and the transport rate of assimilates into grains were accelerated, resulting in higher grain weight, yield, and water use efficiency(WUE). However, under SWD treatment, exogenous ABA improved the ratio of SA/ABA, leading to low Pro content and low antioxidant enzyme activity of flag leaves in the rapid loss phase. Meanwhile,drought resistance declined and the transport duration of assimilates into grains was shortened, thus making photosynthetic assimilates redundant. Therefore, exogenous ABA can lead to the reduction in grain weight, yield, and WUE of wheat under SWD treatment.展开更多
The paper aimed to study the effects of exogenous hormone on fecundity of silver fox. Vixens were timely injected with appropriate exogenous hormones at proper ratio to increase their ovulation and litter size, thereb...The paper aimed to study the effects of exogenous hormone on fecundity of silver fox. Vixens were timely injected with appropriate exogenous hormones at proper ratio to increase their ovulation and litter size, thereby improving the fecundity of silver fox. The average litter size in experimental group attained by 5.86 to 6.0 whelps, 1.61 - 1.75 whelps more than that in the control group. The hormone combination in the experimental group was high in performance/price ratio, which had no significant impact on fecundity of vixens in future.展开更多
To explore breast cancer etiology, literature was searched using Medline. We explored the (1) plausibility of smoking in breast carcinogenesis; (2) physiological properties, susceptibility windows, and exposure timing...To explore breast cancer etiology, literature was searched using Medline. We explored the (1) plausibility of smoking in breast carcinogenesis; (2) physiological properties, susceptibility windows, and exposure timing of breast cells; (3) role of exogenous hormones in breast carcinogenesis; (4) biological mechanism of synergistic interactions between smoking and exogenous hormones in breast carcinogenesis; and (5) evidence from epidemiologic studies and the fitted secular trend between smoking rate, exogenous hormone use, and breast cancer incidence in past decades. We deduced that exogenous hormone use per se is not a significant cause and its association with breast cancer is distorted by chronic exposure to environmental carcinogens, especially smoking. We hypothesize that smoking is one of the causes of breast cancer and that this causality is strengthened by synergistic interaction between smoking and exogenous hormone use. Physicians should be cautious of prescribing exogenous hormones for those with chronic exposure to environmental carcinogens to prevent breast cancer.展开更多
Objectives] This study was conducted to investigate the regulatory mechanism of ethylene on DpXTH gene expression in dahlia （ Dahlia pinnata Cav.） flower petals.[Methods] Dahlia flower petals were treated with ethep...Objectives] This study was conducted to investigate the regulatory mechanism of ethylene on DpXTH gene expression in dahlia （ Dahlia pinnata Cav.） flower petals.[Methods] Dahlia flower petals were treated with ethephon （ETH） and 1-methylcyclopropene （1-MCP） at different flower development stages and for different durations in vivo . Then, the relative expression of DpXTH1 and DpXTH2 in flower samples in different treatments was quantified with real-time PCR, using β-actin as a reference gene.[Results] The expression of DpXTH1 and DpXTH2 in ETH- or 1-MCP-treated dahlia flower petals increased at first, and decreased subsequently with increasing duration of treatment. The relative expression of both DpXTH1 and DpXTH2 in ETH-treated samples reached the maximum level at 12 h. Moreover, the relative expression of both DpXTH1 and DpXTH2 in dahlia flower petals treated with ETH at early stage of flowering was higher than that of the samples treated at other flowering stages; in 1-MCP-treated samples, it was higher at full-flowering stage than at other stages. The maximum relative expression levels of DpXTH1 and DpXTH2 in ETH- and 1-MCP-treated samples were all higher than those of control.[Conclusions] Exogenous ethylene can accelerate the opening of dahlia flowers, and 1-MCP can inhibit this process, so they can be used to regulate development of dahlia flowers.展开更多
基金Supported by Post-graduate Innovation Program of Guangxi(YCSZ2013007)~~
文摘Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedlings of Guisangyou 12 were used as the materials and the comparative experiment on subculture multi-plication and root induction used different kinds,concentrations and combinations of exogenous hormones. [Result] The hormone combination of 0.1 mg/L IBA＋1.5 mg/L 6-BA＋0.03 mg/L TDZ showed the best effects to bud multiplication, and the multiple of bud multiplication was 5.28. The effects of NAA was better than IBA and IAA on root induction. The hormone combination of 2.0 mg/L NAA＋1.0 mg/L PP333 was most suitable to the root induction, in which the rooting rate arrived to 100%, the root number was 7.01 and the root length was 1.38 cm on average. [Conclusion] The results wil provide some technical reference for large-scale propagation of mul-berry seedlings in vitro.
基金supported by the National Key Research and Development Program of China(grant Nos.:2017YFD0301001 and 2016YFD0300403)the Shandong Province Mount Tai Industrial Talents Programthe National Natural Science Foundation of China(grant No.:31801295)。
文摘Drought at the grain filling stage of wheat will cause premature leaf senescence, thus leading to considerable loss of wheat yield. Therefore, this paper aims to establish a cultivation technology for strong drought resistance, delayed senescence, and yield improvement based on the analysis of hormones homeostasis obtained by applying chemical control substances. Experiments were conducted with two genotypes of wheat. Four water irrigation treatments were applied to impose the water deficit, including well-watered control treatment(WW), mild water deficit(MiWD), moderate water deficit(MoWD), and severe water deficit(SWD). Exogenous abscisic acid(ABA) was sprayed on the plants at the anthesis stage of the wheat. As a result, exogenous ABA reduced initial senescence rate(r0), total duration of chlorophyll(Chltotal), rapid senescence phase(Chlloss), and the accumulated temperature at an inflection point(M) but improved the persistence phase(Chlper) of flag leaves under all of the four treatments. However, exogenous ABA produced inconsistent effects on photoassimilate relocation and grain weight under different treatments. It produced positive regulatory effects on grain weight under WW, MiWD, and MoWD treatments. On the one hand, spraying ABA during the persistence phase of flag leaves reduced the ratios of zeatin to gibberellin(Z/GA3), spermine to spermidine(Spm/Spd), and salicylic acid to ABA(SA/ABA),which prolonged active photosynthesis by stimulating high level of proline(Pro) and increased the activities of antioxidant enzymes, such as superoxide dismutase(SOD), peroxidase(POD), catalase(CAT), and ascorbate peroxidase(APX). Therefore, drought tolerance was enhanced, and more photosynthetic assimilates were accumulated. On the other hand, the rapid senescence phase and the transport rate of assimilates into grains were accelerated, resulting in higher grain weight, yield, and water use efficiency(WUE). However, under SWD treatment, exogenous ABA improved the ratio of SA/ABA, leading to low Pro content and low antioxidant enzyme activity of flag leaves in the rapid loss phase. Meanwhile,drought resistance declined and the transport duration of assimilates into grains was shortened, thus making photosynthetic assimilates redundant. Therefore, exogenous ABA can lead to the reduction in grain weight, yield, and WUE of wheat under SWD treatment.
文摘The paper aimed to study the effects of exogenous hormone on fecundity of silver fox. Vixens were timely injected with appropriate exogenous hormones at proper ratio to increase their ovulation and litter size, thereby improving the fecundity of silver fox. The average litter size in experimental group attained by 5.86 to 6.0 whelps, 1.61 - 1.75 whelps more than that in the control group. The hormone combination in the experimental group was high in performance/price ratio, which had no significant impact on fecundity of vixens in future.
基金supported by the Department of Epidemiology at the Johns Hopkins University Bloomberg School of Public Health
文摘To explore breast cancer etiology, literature was searched using Medline. We explored the (1) plausibility of smoking in breast carcinogenesis; (2) physiological properties, susceptibility windows, and exposure timing of breast cells; (3) role of exogenous hormones in breast carcinogenesis; (4) biological mechanism of synergistic interactions between smoking and exogenous hormones in breast carcinogenesis; and (5) evidence from epidemiologic studies and the fitted secular trend between smoking rate, exogenous hormone use, and breast cancer incidence in past decades. We deduced that exogenous hormone use per se is not a significant cause and its association with breast cancer is distorted by chronic exposure to environmental carcinogens, especially smoking. We hypothesize that smoking is one of the causes of breast cancer and that this causality is strengthened by synergistic interaction between smoking and exogenous hormone use. Physicians should be cautious of prescribing exogenous hormones for those with chronic exposure to environmental carcinogens to prevent breast cancer.
基金Supported by Applied Basic Research Project of Suzhou City(SYN201405)
文摘Objectives] This study was conducted to investigate the regulatory mechanism of ethylene on DpXTH gene expression in dahlia （ Dahlia pinnata Cav.） flower petals.[Methods] Dahlia flower petals were treated with ethephon （ETH） and 1-methylcyclopropene （1-MCP） at different flower development stages and for different durations in vivo . Then, the relative expression of DpXTH1 and DpXTH2 in flower samples in different treatments was quantified with real-time PCR, using β-actin as a reference gene.[Results] The expression of DpXTH1 and DpXTH2 in ETH- or 1-MCP-treated dahlia flower petals increased at first, and decreased subsequently with increasing duration of treatment. The relative expression of both DpXTH1 and DpXTH2 in ETH-treated samples reached the maximum level at 12 h. Moreover, the relative expression of both DpXTH1 and DpXTH2 in dahlia flower petals treated with ETH at early stage of flowering was higher than that of the samples treated at other flowering stages; in 1-MCP-treated samples, it was higher at full-flowering stage than at other stages. The maximum relative expression levels of DpXTH1 and DpXTH2 in ETH- and 1-MCP-treated samples were all higher than those of control.[Conclusions] Exogenous ethylene can accelerate the opening of dahlia flowers, and 1-MCP can inhibit this process, so they can be used to regulate development of dahlia flowers.
