低温弱光对辣椒苗期生长发育及生理特性的影响

以4个对低温弱光耐受性不同的辣椒品种为试验试材,用4种不同的温度光照组合进行低温弱光处理。试验的结果表明:低温弱光处理后,所有试材的植株生长指标均有所下降;超氧化歧化酶(SOD)活性下降;膜脂过氧化产物丙二醛(MDA)含量明显增加;叶片内源激素中生长素(IAA)和赤霉素(GA3)均明显下降,而脱落酸(ABA)含量增加。     

NaCl浓度对SBBR同步脱氮及N2O释放的影响

盐度是影响生物脱氮过程的重要因素。盐度增加会导致生物硝化和反硝化过程中N_2O的产生并释放。该文以添加NaCl的生活污水为研究对象,采用固定填料序批式生物膜反应器(sequencing batch biofilm reactor,SBBR),考察了不同NaCl浓度(0、5、10、15和20g/L)对SBBR脱氮性能及N_2O释放的影响。结果表明,试验NaCl浓度范围内,SBBR出水COD稳定在40～60mg/L。硝化过程NO_2~-/NO_3~-随NaCl浓度增加而增加。NaCl浓度≤10g/L时,NH_4~+-N去除率大于95%,N_2O产率由4.08%(NaCl浓度为0)增至6.72%(NaCl浓度为10 g/L)。NaCl浓度为20 g/L时,驯化后SBBR内平均NH_4~+-N去除率为70%,平均N_2O产率为13.60%。无添加NaCl时,N_2O主要产生于硝化阶段的AOB好氧反硝化过程,SBBR内缺氧区有助于减少N_2O释放;高NaCl浓度条件下,N_2O主要产生于AOB好氧反硝化过程和内源同步反硝化过程,高盐度加剧内源反硝化阶段NO_2~-和N_2O之间电子竞争,抑制N_2O还原,其活性抑制性能与电子受体和初始C/N有关。与硝态氮还原速率和亚硝态氮还原速率相比,氧化亚氮还原速率受NaCl抑制最为明显,是导致高盐度条件下N_2O释放量增加的重要因素。     

The influence of reproductive status on the stimulatory action of N-methyl-D,L-aspartate on growth hormone secretion, in vitro in rainbow trout, Oncorhynchus mykiss

The glutamate agonist, N-methyl-D,L-aspartate (NMA) stimulates the secretion of growth hormone (GH) from pituitary fragments in vitro and increases plasma GH levels in vivo in rainbow trout, Oncorhynchus mykiss (Flett et al. 1994; Holloway and Leatherland 1997a,b); however gonadal steroid hormones appear to modulate this response in experimental situations. This study examines whether steroid hormones also modulate the GH-regulatory actions of NMA during the normal reproductive cycle of rainbow trout by examining the relationship between the stage of sexual maturation and the pituitary release of GH in vitro in response to an NMA (10^-8 M) challenge. NMA had no effect on mean GH release from the pituitary glands of fish that were immature (GSI <1.0), from males during early development (GSI 1.0-3.0), or from sexually mature males (with free running milt) and females (ovulated). However, NMA significantly increased GH release from pituitary glands taken from females during the early stages of gonadal growth (GSI 1.0-9.0) and from males and females sampled during the later stages of gonadal growth (males GSI 3.01-6.0; females GSI 9.01-15.0). The GH-stimulatory action of NMA in males and females progressed to a maximum effect during the late stages of gonadal growth, and disappeared in ovulated females and free running males. Moreover, in female fish, the maximal GH release in response to the NMA challenge is positively correlated with plasma 17β-estradiol levels; no such correlation was evident for plasma testosterone levels in males. Changes in the GH response to NMA during maturation while gonadal steroid levels fluctuate provides further evidence to suggest that the effects of NMA on GH secretion are intimately linked to endogenous gonadal steroid hormone levels. This revised version was published online in July 2006 with corrections to the Cover Date.     

防御相关激素与纹枯病菌处理下水稻VQ基因家族的转录分析

VQ蛋白与WRKY转录因子互作,调节植物防御反应.本研究分析了水稻VQ基因家族在水杨酸(SA)、茉莉酸(JA)、乙烯(ET)3种防御相关激素和纹枯病菌(Rhizoctonia solani)处理下的转录表达谱.结果表明,水稻VQ基因家族有1/3以上成员至少响应一种处理,OsVQ2、-11和-35的表达在3种激素处理下均...     

Role of thyroid hormones in tilapia larvae (Oreochromis mossambicus): II. Changes in the hormones and 5′-monodeiodinase activity during development

Thyroid hormone profiles and 5-monodeiodinase activity were determined in tilapia at different stages of early development. The results showed that both T₄ and T₃ were present in significant amounts in fertilized eggs. There was a steady decrease in both T₄ and T₃ levels during embryonic development. The levels continued to decline after hatching until around 7 days later when most of the yolk had been absorbed. The T₄ level started to rise then, suggesting that the larval thyroid had begun to produce T₄ at this time, which coincided with the period of faster growth of the larvae. The T₃ level remained fairly constant until around 20 days after which it rose significantly. In vitro determination of 5-monodeiodinase activity (5-D activity) in the whole-body homogenates of larvae showed that the enzymatic conversion of T₄ to T₃ was not detectable in eggs and 3-day-old larvae but detected in 5-day-old and older larvae. There was a gradual increase in the V_max as development proceeded indicating increasing 5-D activity during larval development. The K_m values did not differ significantly in the different stages of development. These results are discussed in relation to the growth and development of the larvae.     

Hormonal disturbances associated with obesity in dogs

Obesity is associated with multiple endocrine alterations and changes in the concentration of circulating hormones. However, few studies have explored such alterations in dogs with naturally acquired excess weight. In the present study, we investigated the effect of naturally acquired obesity on cortisol, insulin-like growth factor (IGF)-1 and prolactin secretion in dogs. Thirty-one overweight dogs were enrolled in the trial. Blood samples were collected before and after adrenocorticotrophic hormone (ACTH) injection. Free thyroxine (fT4), cortisol, thyroid-stimulating hormone (TSH), IGF-1, prolactin and fructosamine were assayed. Body weight excess increased significantly with age and neutered dogs were more obese than entire ones. The ACTH stimulation test was within the normal range for 26 of 31 dogs. Prolactinaemia was increased in seven dogs and IGF-1 in six dogs. Twenty dogs had a fructosamine concentration >340 microm. Interestingly, 18 of 31 dogs showed disturbances of thyroid function based on high TSH and/or low fT4 baseline concentration, with 11 dogs showing both. According to these parameters only six of 31 dogs were free of hormonal disturbances. These results revealed the high incidence of such disturbances, especially thyroid dysfunction, in obese, but otherwise apparently healthy dogs. They demonstrate the importance of examining endocrine function during the initial evaluation of obese dogs to avoid failure of any nutritional treatment.     

不同熟期夏玉米品种籽粒灌浆脱水特性和激素含量变化

本文旨在研究不同熟期夏玉米品种籽粒灌浆与脱水特性和内源激素含量与平衡的变化,以期为黄淮海夏玉米机械化收获籽粒和高产高效品种筛选提供理论依据。以早熟玉米品种登海518(DH518)、衡早8号(HZ8)和晚熟玉米品种郑单958(ZD958)、登海605(DH605)为试验材料,研究玉米籽粒形成过程中干物质积累、水分含量及内源激素含量变化。结果表明,早熟品种较晚熟品种灌浆期短,籽粒开始脱水早,脱水速率高,生理成熟期粒重低,产量低,但早熟品种中DH518的产量显著高于HZ8。不同熟期玉米品种籽粒内源激素含量及其变化模式不同,但同一激素含量随籽粒发育的变化趋势一致。两早熟品种籽粒的ABA含量高于两晚熟品种,尤其表现在灌浆中后期。各品种籽粒灌浆、脱水速率均与内源激素含量有关,两早熟品种的籽粒脱水速率与玉米素核苷(ZR)含量呈显著正相关。     

The impact of bisphenol S on bovine granulosa and theca cells

Bisphenol S (BPS) is an endocrine‐disrupting chemical with multiple potential mechanisms of action, including as an oestrogen receptor agonist. BPS is increasingly used in plastics and thermal receipts as a substitute for bisphenol A, which has been phased out due to concerns about human health implications. The ability of BPS to alter female reproductive function in mammals has not been widely studied, despite the importance of normal hormone signalling for female reproduction. The aim of this study was to investigate how BPS (in a wide range of doses, including very low doses) affects granulosa cell and theca cell steroid hormone production and cell viability in the bovine. Granulosa cell oestradiol production was stimulated when cells were exposed to 100 μM BPS under basal conditions, but there was no effect of BPS when cells were stimulated with follicle‐stimulating hormone (FSH). Additionally, there was no effect of BPS on granulosa cell progesterone production or cell viability under basal or FSH‐stimulated conditions. BPS did not affect theca cell androstenedione or progesterone production, or theca cell viability under basal or luteinizing hormone‐stimulated conditions. This study suggests for the first time that BPS may alter oestradiol production by bovine granulosa cells, albeit at a concentration that is unlikely to be physiologically relevant. Further studies are needed to determine the effects of BPS on the bovine oocyte and on other functions of follicular cells.     

夜间补光对黄瓜幼苗激素含量及养分吸收的影响

为了明确夜间补光在育苗中的作用及机理,以‘津研四号’为试材,研究了夜间补光0、3、6、9和12 h对黄瓜幼苗生长、内源激素含量、根系活力及养分吸收的影响。结果表明：与对照（补光0 h）相比,夜间补光处理的黄瓜幼苗干重、叶面积、根冠比、壮苗指数、矿质元素积累量、吲哚乙酸(IAA)、赤霉素(GA3)、(ZR+GA3+IAA)/ABA和根系活力提高,脱落酸(ABA)含量降低,这些指标的升高（或降低）幅度随补光时间的延长而增大。黄瓜幼苗的玉米素核苷(ZR)含量补光时间的延长先增加后降低,补光6 h的最高。说明夜间补光能促进黄瓜幼苗生长,这与内源激素含量、根系活力及矿质元素积累量的改变有关。     

花椰菜温敏雄性不育系GS-19花蕾发育过程中内源激素的动态变化分析

为了探究内源激素在花椰菜温敏雄性不育系GS-19育性调控中的作用,以花椰菜温敏雄性不育系GS-19为材料,采用高效液相色谱法,对花椰菜温敏雄性不育系的不育株和可育株花蕾不同发育时期及叶片中赤霉素(GA)、生长素(IAA)、脱落酸(ABA)及玉米素核苷(ZR)的动态变化进行比较分析。结果表明,花椰菜温敏雄性不育系花蕾和叶片发育过程中,不育株和可育株内源激素GA、IAA、ABA和ZR的变化均存在明显差异。不育株花蕾中的GA和ABA含量总体呈上升趋势,GA含量在造孢时期、四分体时期及花粉成熟期的含量均显著高于可育株,分别为281.54、355.37和350.13μg·g~(-1),比可育株花蕾高45.1%、210.4%和54.5%,而ABA含量只在四分体时期和花粉成熟期显著高于可育株,分别为2.22μg·g~(-1)和2.88μg·g~(-1),比可育株花蕾高82%和35.2%;不育株花蕾中的IAA含量先降后升,在造孢时期和花粉成熟期显著高于可育株,分别为1.97μg·g~(-1)和2.55μg·g~(-1),比可育株花蕾高52.7%和82.1%,但不育株花蕾的ZR含量先升后降,在四分体和花粉成熟期显著高于可育株,分别为320μg·g~(-1)和170μg·g~(-1),比可育株花蕾高580.9%和243.9%。不育株的IAA/ABA呈"V"字型变化,在四分体时期比值最低,而GA/ABA和ZR/ABA呈倒"V"字型的变化,在四分体时期比值最高。叶片中ABA和ZR未检出,GA和IAA含量不育株显著高于可育株。说明内源激素含量升高和多种激素间的平衡关系被打破,比例失调,阻碍了小孢子的正常发育,导致花椰菜温敏雄性不育系GS-19花粉败育。本研究结果对揭示内源激素在雄性败育过程中可能存在的作用机制具有重要意义,为进一步揭示花椰菜温敏雄性不育的遗传机制积累了资料。