The Structural Characterization of a Novel Water-Soluble Polysaccharide from Edible Mushroom Leucopaxillus giganteus and Its Antitumor Activity on H22 Tumor-Bearing Mice

In the present study, a novel cold water-soluble polysaccharide fraction (LGP) with the average molecular weight of 1.78×10⁶ Da was extracted and purified from Leucopaxillus giganteus and its primary structure as well as in vivo antitumor activity was evaluated. The monosaccharide composition of LGP was determined by ion chromatography to be galactose, xylose, glucose and fucose in a molar ratio of 2.568 : 1.209 : 1 : 0.853. Its backbone was composed of α-D-Glu, α-D-Xyl, α-D-Gal and α-L-Fuc. The results of in vivo antitumor experiment demonstrated that LGP could effectively protect immune organs, has excellent antitumor activity, and inhibit the proliferation of H22 solid tumors in a dose-dependent manner. By analyzing Annexin V-FITC/PI staining, cell cycle and mitochondrial membrane potential detection assay, we concluded that LGP induced apoptosis of H22 cells via S phase arrest and mitochondria-mediated apoptotic pathway. Our results could provide valuable information for the potential application of LGP as an anti-hepatoma agent.     

Plant growth regulators from the fruiting bodies of Tricholoma flavovirens

A novel indole derivative (1) and three known compounds (2–4) were isolated from the fruiting bodies of Tricholoma flavovirens. Their structures were determined or identified by the interpretation of spectroscopic data. Compounds 1 and 2 promoted root growth of lettuce and inhibited hypocotyl growth at 1 μmol/paper. Compound 3 inhibited hypocotyl and root growth at 100 nmol/paper.     

Survival prediction and response to immune checkpoint inhibitors: A prognostic immune signature for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers all over the world. Several studies have explored if immune-related genes and tumor immune microenvironment could play roles in HCC prognoses. This study is aimed at developing a prognostic signature of HCC based on immune-related genes or tumor immune microenvironment to predict survival and response to immune checkpoint inhibitors (ICIs). We constructed a prognostic signature using bioinformatics method and validated its predictive capability. The mechanisms of the signature prediction were explored with The Cancer Immunome Atlas (TCIA) and mutation analysis. We also explored the association between the signature and immunophenoscore (IPS), which is the marker of ICIs response. A 6 immune-related-gene (6-IRG) signature was developed. It was revealed in a multivariate analysis that the 6-IRG signature was an independent prognostic factor of overall survival and progression-free interval among HCC patients. In the high-risk group of 6-IRG signature score, macrophage M0 cells and regulatory T cells, which are observed associated with poor overall survival in our study, were higher. The low-risk group had a higher IPS, which meant a better response to ICIs. Taken together, we constructed a reliable 6-IRG signature for prediction of survival and response to ICIs. The signature needs further testing for clinical application.     

不同生长调节物质对水稻生长及镉积累的影响

比较脱落酸(ABA)、乙烯利(ETH)、水杨酸(SA)和茉莉酸甲酯(MeJ A)4种植物生长调节物质(PGR)对水稻生长及籽粒镉(Cd)积累的影响差异。试验采用重金属污染土种植水稻,于分蘖期、灌浆期各进行1次PGR叶面喷施处理,分析灌浆期叶片光合指标,丙二醛(MDA)含量以及收获期各部位生物量和Cd含量。结果表明:(1)低浓度ABA(5mg/L)可维持水稻正常产量;高浓度ABA(15mg/L)则导致产量下降。ETH对水稻地上部生长和单株产量有显著抑制作用,SA和MeJ A(0.56mg/L)均可保证地上部正常生长,维持正常产量。(2)外施4种PGR均抑制灌浆期叶片气孔开放,降低蒸腾速率和光合速率,抑制效果最明显的是高浓度MeJ A(0.56mg/L)。(3)在供试浓度范围内SA、低浓度ABA(5mg/L)以及高浓度MeJ A均可降低灌浆期叶片MDA含量,减少质膜过氧化水平。(4)4种PGR均可降低水稻籽粒Cd含量,其中低浓度ABA(5mg/L)抑制籽粒Cd积累的效应最佳。相关性分析结果表明,PGR抑制籽粒积累Cd的效应与地上部向籽粒转运Cd的调控机制有关,与蒸腾速率无显著相关关系。(5)综上所述,低浓度ABA(5mg/L)处理对水稻产量无影响,且籽粒Cd含量降低程度最大。适当浓度的PGR可降低水稻籽粒Cd含量,在中低度重金属污染农田生态修复实践中具有一定的应用前景,但必须精确控制PGR的处理时间和处理浓度,避免出现抑制生长和降低产量的负效应。     

Plant growth regulators and the orchid cut-flower industry

Research involving plant growth regulators (PGRs) and orchids in areas of orchid growth and development are reviewed. For all areas covered in the review — seed germination and seedling growth, lateral shoot production, root production, flower initiation and development, postharvest physiology, and photosynthate partitioning — it was concluded that further studies would assist in clarifying potential uses for PGRs in the orchid cut-flower industry. It is suggested that extra PGR research on orchids is justified at the present time because of favourable prospects facing the orchid cut-flower industry.     

Plant growth regulators from Heracleum lanatum

The plant growth regulating substances, pimpinellin, isopimpinellin, bergapten, isobergapten, vaginidiol, sphondin, scopoletin, umbelliferone, ferulic     

Effect of plant growth regulators on in vitro fiber development from unfertilized and fertilized Egyptian cotton ovules

Unfertilized and fertilized ovules of Gossypium barbadense Giza 45 (extra long staple variety) were used to study the effect of plant growth substances (auxins, gibberellins and cytokinins) on in vitro fiber initiation and development. Kinetin, alone did not increase total fiber unit (TFU) of unfertilized ovules, while an increase in TFU value occurred when a constant level of IAA and GA₃ were used either separately or in combination in the liquid medium. GA₃ used alone, produced a higher TFU value than that produced by IAA, whilst, IAA with a constant level of GA₃ (5 M) produced the highest value of TFU. GA₃ with a constant level of IAA (5 M) produced a lower TFU value. Kinetin reduced the stimulatory effect of IAA and GA₃ on TFU value when used in combination with either substance. In fertilized ovules, the highest level of TFU was reached when IAA, with a constant level of GA₃, was added to the medium, whilst its lowest level was obtained when IAA was used alone. Estimation of in vitro fiber production, as well as the effect of growth substances used in different concentrations on in vitro fiber initiation and development from unfertilized and fertilized ovules of Egyptian cotton varieties Gossypium barbadense Giza 45 are discussed.     

Risk of developing hypothyroidism with the use of tyrosine kinase inhibitors and immune checkpoint inhibitors

BackgroundThe survival rate of patients with cancer has been increasing because of the sustained anticancer effect of new drugs, such as immune checkpoints inhibitors (ICI). Unlike the existing cytotoxic chemotherapies, immunotherapy causes immune system disturbance, such as hypothyroidism. Comparative studies on hypothyroidism following administration of ICI alone and in combination with other drugs are scarce. Therefore, we investigated the incidence of hypothyroidism after ICI in patients with cancer using a national population-based database.MethodsUsing the claims data from the Health Insurance Review and Assessment service in Korea, we retrospectively investigated patients with cancer who received chemotherapy between January 1, 2014 and February 28, 2021.ResultsOf all patients with cancer (n = 665,445) who received all kinds of chemotherapy, those who have received ICI accounted for 1.91 %. Compare with cytotoxic chemotherapy and angiogenesis inhibitors (AIs), ICI was associated with earlier (236.1 ± 248.4 vs. 811.1 ± 661.7, P < 0.01) and more frequent (7.7 % vs. 4.4 %, P < 0.01) occurrence of hypothyroidism, as well as an increased risk of developing hypothyroidism (odds ratio [OR] 1.69, 95 % confidence interval [CI] 1.58–1.80). However, the incidence of grade 2 or higher hypothyroidism was similar in both groups of patients who received ICI (3.3 %) and AI (3.1 %). The incidence of hypothyroidism was 4.4 times higher in patients who received both AI and ICI than in those who were treated with ICI alone (OR 4.41, 95 % CI 3.40–5.71).ConclusionsThis study showed a synergistic effect in patients who received multiple administrations of a drug that might be associated with thyroid dysfunction. Therefore, special attention should be paid to the treatment-related side effects when using drugs, such as AIs, concomitant with ICI treatment.     

植物生长调节剂对西南桦苗木生长的影响

用 ABT6 和 GA3对西南桦苗木进行叶面喷施试验。试验结果表明 ,GA3的 3种浓度即 2 0× 10 - 6 m g/L、50× 10 - 6 m g/L、80× 10 - 6 m g/L在苗木高生长、地径大小、苗木干鲜重及苗木根系生长发育方面都比清水对照( CK)有明显地提高。ABT6 各浓度特别是 50× 10 - 6 m g/L处理的在苗木分枝数、单株叶面积、苗木干鲜重及苗木根系生长发育方面也比对照有显著的提高。综合各指标 ,用 A BT6 生长调节剂的 50× 10 - 6 mg/L比 2 0× 10 - 6mg/L、80× 10 - 6 mg/L处理及 GA3生长调节剂各浓度处理在生产实践上更适宜用于培育西南桦苗木。     

Plant growth regulators and amino acids released by Azospirillum sp in chemically defined media

AIMS: To investigate the ability of Azospirillum sp., a facultative endophitic diazotrophic bacterium, to release plant growth regulators (PGR) such as polyamines, ethylene, indoleacetic acid and amino acids in both combined-N and N-free cultures. METHODS AND RESULTS: The presence of those substances was analysed by HPLC. Azospirillum sp. is capable of releasing PGR and amino acids into the culture medium. CONCLUSIONS: The type and quantity of the released substances varied, depending on the presence of combined-N in the medium. SIGNIFICANCE AND IMPACT OF THE STUDY: A better knowledge of PGR produced by Azospirillum sp. has been gained.     

糖类和植物生长调节剂对冬虫夏草子实体人工培养的影响

为提高人工培养冬虫夏草子实体的产量,需要优化其培养参数。本实验测定培养基中糖类和植物生长调节剂对冬虫夏草子实体产量的影响。于大米小麦作为主要组分的培养基中接入冬虫夏草菌,在9~13℃下培养60 d,转入4℃培养。葡萄糖培养基中,冬虫夏草子实体干重是麦芽糖培养基中的7.6倍,出现菌丝和收获子实体的时间也比麦芽糖培养基中至少快2个月;蔗糖培养基中未获得子实体。不同种类和浓度植物生长调节剂对冬虫夏草子实体产量影响显著。于菌液中加入环磷腺苷、三十烷醇和玉米素的培养瓶均未发现菌丝生长。加入100μg/mL 6-苄氨基腺嘌呤的培养瓶可见菌丝生长,但未见原基分化。转入4℃下6个月后,与对照相比,加入100μg/mL吲哚乙酸、1μg/mL和100μg/mL吲哚丁酸、10μg/mL赤霉素、1μg/mL和10μg/mL乙烯利,以及1μg/mL 2,4-D的培养瓶中子实体干重均显著提高,其中加入1μg/mL吲哚丁酸和1μg/mL 2,4-D的培养瓶的子实体干重是对照的15倍。实验结果为优化冬虫夏草子实体人工培育提供了支撑。     

Plant growth regulators and virus infection: A critical review

Virus infection can severely inhibit plant growth and distort development. This article reviews changes in plant growth regulator metabolism caused by infection. In general, virus infection decreases auxin and gibberellin concentrations and increases abscisic acid concentration. Ethylene production is stimulated in necrotic or chlorotic reactions to infection, but not where the virus spreads systemically without necrosis. While these broad trends are true for most host-virus combinations studied, several situations are recorded where the virus had other effects on growth substance concentration. Cytokinin changes do not show any common pattern: both increases and decreases after infection have been reported.The extent to which virus-induced changes in growth substance concentration could be responsible for observed alterations in host growth and development is discussed. While changes in abscisic acid, gibberellin and ethylene production seem potentially important, the experimental evidence does not provide conclusive proof for control of growth by these changes.The numerous investigations of effects of exogenous regulators on virus multiplication and pathogenesis are reviewed. Different regulators, or the same regulator applied at different times or concentrations, had very diverse effects, and in some cases did significantly alter virus multiplication and pathogenesis. However, such studies seem to have yielded disappointingly little understanding of the biochemistry of the host-virus interaction, and the possible involvement of growth substances in this.Possible uses of plant growth regulators in chemotherapy of virus disease, and their possible involvement in natural or induced resistance mechanisms are discussed.     

Commercially available plant growth regulators and promoters modify bulk tissue abscisic acid concentrations in spring barley, but not root growth and yield response to drought

Field and lysimeter experiments were conducted in 2002 to investigate the effects of an antigibberellin growth regulator (Moddus, active ingredient trinexapac‐ethyl, Syngenta Crop Protection UK Ltd, Whittlesford, Cambridge, UK) and an auxin‐stimulating (Route, active ingredient zinc ammonium acetate, De Sangosse Ltd, Swaffham Bulbeck, Cambridge, UK) growth promoter on root growth, soil water extraction and the drought response of spring barley. The effects on root growth and distribution were investigated in the field. The effects on the drought response were studied in 1.2‐m‐deep lysimeters packed with a loamy sand subsoil and sandy loam topsoil. Lysimeters were located under a fixed rain shelter, and drought was imposed by withholding irrigation. In both field and lysimeter experiments, growth regulator/promoters were applied to cv. Optic at early tillering according to the manufacturers’ recommendations. After withholding irrigation from lysimeters at Zadoks growth stage (GS) 21 (37 days after sowing), 50% of the profile available water had been depleted by flag leaf emergence (GS 37/39; 62 days after sowing). Drought significantly reduced stem biomass at ear emergence (GS 59; 78 days after sowing) but not leaf or ear dry weight; this was before there was any significant reduction in leaf water potential or stomatal conductance to water vapour. The reduction in stem biomass may reflect a change in partitioning between shoot and root in response to soil drying. When averaged over growth regulator/promoter treatments, drought reduced grain yield by approximately 1 t ha^?1. This was associated with a reduction in both ears per m² and grains per ear. The mean grain weight was not reduced by drought, in spite of significant reductions in stomatal conductance and canopy lifespan post‐anthesis. Route, and to a lesser extent Moddus, significantly increased abscisic acid accumulation in the stem base of droughted plants, and there was some indication of a possible delay in stomatal closure in Route‐treated plants as the soil moisture deficit developed. However, there was no significant effect on the amount of soil water extracted or grain yield under drought. Similarly, in field experiments, neither Route nor Moddus significantly altered total root length, biomass or distribution. There is little evidence from these experiments or in the literature to support the use of antigibberellin or auxin‐simulating growth regulator/promoters to modify root growth and drought avoidance of spring barley.     

Protein accumulation potential in barley seeds as affected by soil- and peduncle-applied N and peduncle-applied plant growth regulators

Although much investigated, the factors constraining cereal grain protein accumulation are not well understood. As a result of the development of a new technique, new approaches to this question are now possible. A peduncle perfusion system was used to deliver a range of plant growth regulators (PGRs) and/or N solutions into barley (Hordeum vulgare) plants during the grain-filling period. The perfusion technique floods the peduncle interior with a treatment solution for periods of weeks to months, allowing the plant to take up administered substances from the perfused solution. The objectives of the present work were to determine: (1) whether some PGRs could alter the overall pattern of N allocation within barley plants, perhaps leading to higher protein accumulation in the seeds, (2) whether the addition of N through the peduncle could increase the seed N concentration even when the concentration of N in the rooting medium was high, and (3) whether or not PGR-stimulated elevations in grain protein levels and peduncle-added N increases in grain protein levels were additive. Three experiments were conducted to determine the physiological effects of (1) peduncle-administered PGRs (2) combinations of soil- and peduncle-applied N and (3) selected combinations of soil- and peduncle-administered N, and peduncle-applied PGRs on photosynthetic rate, dry matter partitioning and N accumulation of barley plants during grain filling. The first experiment tested four PGRs: abscisic acid (ABA), kinetin, gibberellic acid (GA₃), and 2,4-dichlorophenoxy acetic acid (2,4-D) each at three concentrations. The second experiment tested three levels of soil N (NH₄NO₃) fertility, and two concentrations of peduncle-added N (urea). The third experiment tested four PGRs: ABA, kinetin, GA₃, and 2,4-D with two soil N concentrations and two concentrations of peduncle-added N. ABA and 2,4-D decreased total seed weight of the perfused spike. The addition of peduncle-perfused N increased seed protein concentration and content under conditions of high soil N fertility, suggesting that seed protein accumulation is more limited by the ability of roots to take up N from the soil than by the seed to take up N from the rest of the plant. The effects of the PGRs on N allocation among plant parts varied with the amount of N available to the plant. Because it resulted in less protein stored in the flag leaf and more in the seeds, GA₃ perfusion caused an overall change in the allocation of N among plant parts. Peduncle perfusion of kinetin and ABA affected some aspects of photosynthetic physiology.     

Phenolic plant growth inhibitors from the flowers of Cucurbita pepo

Eleven compounds isolated from the growth inhibiting active fraction of male flowers of Cucurbita pepo, were identified as p-hydroxybenzaldehyde, anisyl alcohol, p-hydroxybenzyl methyl ether, p-hydroxybenzyl alcohol, veratryl alcohol, isovanillyl alcohol, p-coumaric acid, phloretic acid, benzyl-β-d-glucoside, 4-methoxybenzyl-β-d-glucoside and 3, 4-dimethoxybenzyl-β-d-glucoside. Each compound was assayed for growth inhibiting activity using lettuce seedlings; three showed strong activity, whereas the glucosides were inactive.     

Requirement of vesicle-associated membrane protein 721 and 722 for sustained growth during immune responses in Arabidopsis

Extracellular immune responses to ascomycete and oomycete pathogens in Arabidopsis are dependent on vesicle-associated secretion mediated by the SNARE proteins PEN1 syntaxin, SNAP33 and endomembrane-resident VAMP721/722. Continuous movement of functional GFP-VAMP722 to and from the plasma membrane in non-stimulated cells reflects the second proposed function of VAMP721/722 in constitutive secretion during plant growth and development. Application of the bacterium-derived elicitor flg22 stabilizes VAMP721/722 that are otherwise constitutively degraded via the 26S proteasome pathway. Depletion of VAMP721/722 levels by reducing VAMP721/722 gene dosage enhances flg22-induced seedling growth inhibition in spite of elevated VAMP721/722 abundance. We therefore propose that plants prioritize the deployment of the corresponding secretory pathway for defense over plant growth. Interstingly, VAMP721/722 specifically interact in vitro and in vivo with the plasma membrane syntaxin SYP132 that is required for plant growth and resistance to bacteria. This suggests that the plant growth/immunity-involved VAMP721/722 form SNARE complexes with multiple plasma membrane syntaxins to discharge cue-dependent cargo molecules.     

Repraesentins D,E and F,New Plant Growth Promoters from Lactarius repraesentaneus

Three new plant growth regulatory sesquiterpenes were isolated from the Lactarius repraesentaneus fungus. Their structures were elucidated to be lactarane sesquiterpenes, namely repraesentins D (1) and E (2), and a protoilludane-related sesquiterpene, namely repraesentin F (3). Repraesentin E (2) showed the strongest promotion activity, 164% at 3.6 μM, of the three compounds toward the radicle elongation of lettuce seedlings.     

六种昆虫生长调节剂对葱蝇生长发育和繁殖力的影响

用灭蝇胺、氟铃脲等6种昆虫生长调节剂和对比药剂辛硫磷LC_40-50浓度处理葱蝇1龄和3龄幼虫,观察对其生长发育和繁殖的影响;并且研究了葱蝇成虫取食药剂对其繁殖力的控制效应。结果表明：6种药剂中除虫酰肼外,其余都对葱蝇幼虫发育历期、化蛹率、成虫产卵前期、成虫寿命、产卵量有很大影响,对其生长发育和繁殖表现出显著不利性。其中灭蝇胺和氟铃脲处理1龄幼虫后,存活幼虫的历期和成虫产卵前期各延长3天,化蛹率降低26.7%～30.0％,成虫寿命缩短22.3～24.3天,产卵量降低35.5％～49.9％;处理3龄幼虫主要导致产生畸形蛹,且正常羽化的成虫寿命降低18.0～20.67天,产卵量降低45.7%～57.8％。成虫连续取食用牛奶稀释的２ 000倍的药液,能导致产卵前期延长、产卵量减少、卵孵化率降低,幼虫死亡率极高,达95%以上。结果提示,利用成虫补充营养的特性,将灭蝇胺和氟铃脲等混入牛奶或糖水中诱集成虫取食,可有效降低成虫的繁殖力,有助于实现对葱蝇的无公害治理。     

柑橘用植物生长调节剂的登记与安全施用

为了加强植物生长调节剂在柑橘生产上的安全使用,对其登记信息现状的全面了解是非常有必要的.鉴于此,本文检索了目前在中国农药信息网上登记的产品,并对有效期内可用于柑橘生产的植物生长调节剂的种类、剂型与功效进行科学统计和分析,进一步提出安全施用建议及展望.结果表明,当前所登记的柑橘植物生长调节剂产品总共有75个,有效成分主要以单剂为主,产品有65个,占86.67%;剂型有12类,以可溶液剂和乳油为主,占46.7%;功效主要包含调节生长、增产、催熟、控梢、矮化、杀虫、促进生长、抗逆等作用.该结果为植物生长调节剂产业健康发展与柑橘的绿色生产提供参考.