6-BA、IAA、GA_3与ABA对木枣果实成熟衰老的调控作用

在木枣白熟期,用不同的植物激素处理果实,通过检测其生理生化变化,研究6-BA、IAA、GA3与ABA对枣果实成熟衰老的调控作用。结果显示,6-BA、IAA、GA3和ABA处理后枣果中DNA含量差异较为明显,其中,ABA和6-BA处理效果显著;GA3和IAA处理后枣组织中的丙二醛(MDA)含量明显低于对照组,6-BA和ABA处理则相反;除ABA处理外,枣组织中脯氨酸(Pro)含量明显低于对照组,维生素C(Vc)含量变化则相反;过氧化氢酶(CAT)活性表现差异很大,ABA和6-BA处理CAT活性显著高于对照组,IAA和GA3处理则相反。6-BA、IAA、GA3与ABA的生理作用在多方面表现为相互促进与互为拮抗的关系,有调控木枣果实成熟衰老的作用。     

经低温贮藏的兰州百合种球种植后的鳞茎生长过程中GA3和ABA含量变化

6℃下贮藏67和101d的兰州百合种球种植后,于花蕾伸出顶端2-3cm时将其摘除,以后定期取样,检测鳞茎膨大成熟过程中GA3和ABA含量的结果表明：6℃下处理101d的母鳞茎中GA3含量先上升后下降,而处理67d的则相反;新鳞茎中GA3含量呈升高趋势,处理101d的含量高于处理67d的。母鳞茎中ABA含量先下降后上升,处理67d的高于处理101d的,新鳞茎中则相反。母鳞茎中GA3／ABA比值先升高后下降,处理101d的高于处理67d的;新鳞茎中则显著下降。据此认为,在百合鳞茎膨大成熟过程中,GA3和ABA之间的含量和作用并不全是互为消长的关系。     

外源脱落酸和赤霉素对红肉脐橙果肉糖含量的影响

在红肉脐橙幼果期和着色前分2次喷施不同浓度的外源ABA和GA3,研究其对红肉脐橙果肉糖含量的影响.结果表明:10mg.L-1ABA处理显著或极显著提高了果实成熟时的葡萄糖、果糖和总糖含量,50mg.L-1ABA处理极显著提高了果实蔗糖含量,而100mg.L-1ABA处理极显著降低了果实葡萄糖含量;中低浓度的GA3(10、50和250mg.L-1)极显著提高了果实蔗糖含量,10mg.L-1GA3处理对果实葡萄糖和果糖含量无明显影响,但极显著提高了果实总糖含量,50、250和500mg.L-1GA3处理极显著降低了果实葡萄糖、果糖和总糖含量.表明着色前较低浓度的外源ABA处理(10和50mg.L-1)可提高果实中一种或几种糖的含量,而较高浓度的GA3处理(250和500mg.L-1)则严重阻碍了果肉中糖的积累.     

水培条件下不同磷水平对毛竹实生苗生长发育的影响

以毛竹(Phyllostachys edulis)实生苗为材料,采用Hoagland营养液水培方法,研究不同磷浓度下毛竹生长、根系发育、激素含量等的差异。结果表明:磷浓度较低时,可以促进毛竹实生苗根系长度及根系总表面积的增长。随着磷浓度的增加,实生苗生物量干重及根冠比呈先上升后下降趋势,磷浓度为1 mmol L-1时达到最大。无磷处理时,根中的IAA、ZR、GA3和ABA等4种内源激素含量随着处理时间的延长均先升高再降低;其他浓度磷处理根中IAA、ZR和GA3(0.5 mmol L-1磷除外)含量随着处理时间的延长大致呈先降低后升高的趋势,而ABA(0.5 mmol L-1磷除外)含量随着处理时间的延长变化不明显。不同浓度磷处理,叶片中IAA、GA3和ABA含量总体上呈下降趋势,ZR含量总体上呈上升趋势。以上结果表明不同浓度的磷处理对毛竹内源激素含量的变化有显著的影响,而内源激素含量变化与毛竹实生苗根系变化密切相关。     

外源ABA和GA3对红肉脐橙果皮主要色素含量变化和果实着色的影响

测定了红肉脐橙(Citrus sinensis Osbesk cv.Cara Cara)果实发育期间和果实转色前用不同浓度的外源ABA和GA3处理后果皮叶绿素和类胡萝卜素的动态含量,并测定了外源ABA和GA3处理后成熟红肉脐橙果皮色泽的表现.结果表明红肉脐橙果皮叶绿素含量于9月20日出现最大值,为0.146 9 mg*g-1FW;类胡萝卜素含量于12月20日达到最大值,为0.032 1 mg*g-1FW;果实转色前,用外源ABA处理后加速了果皮叶绿素的降解,但也抑制了果皮类胡萝卜素的积累,用GA3处理后延缓了果皮叶绿素的降解,同样抑制了果皮类胡萝卜素的积累,严重阻碍了果皮类胡萝卜素的合成;外源ABA或GA3处理均不利于果实色泽品质的提高.     

香梨果实成熟衰老过程中4种内源激素的变化

以库尔勒香梨[白梨(PyrusbretschneideriRehd.)的变种]为材料,在果实生长发育、成熟衰老期间检测内源IAA、GA3、ABA、乙烯含量变化规律及其相互关系。结果表明果实发育初期IAA、GA3、ABA含量最高,有利于幼果坐果;CA3与ABA的比值变化对果实迅速膨大起关键作用;高浓度GA3对阻抑叶绿素分解起明显作用;果实成熟衰老期间,IAA含量与乙烯释放速率呈方向相同的变化;在此期间GA3含量变化与乙烯释放变化相反。     

气调和乙烯对梅果叶绿素和内源激素含量的影响

本文研究了在 ( 2 5± 1 )℃下 ,气调包装和乙烯吸收剂处理对采后青梅果实叶绿素含量、内源激素IAA ,GA3,ABA含量和乙烯释放量的影响及它们之间的关系。结果表明 :气调包装果实叶绿素含量最高 ,其次是乙烯吸收剂处理的 ;各处理中气调包装果实的乙烯释放量始终很低 ,GA3含量较高 ,IAA和ABA含量则较低 ;对照果实的则相反 ,乙烯释放量很高 ,IAA和ABA含量较高 ,而GA3含量较低。乙烯吸收剂处理的处于二者之间。气调包装可以维持果实较高的GA3水平 ,降低ABA含量 ,保持较高的GA3/ABA值 ,抑制IAA和乙烯的生成 ,延缓梅果叶绿素的降解。     

气调和乙烯对梅果叶绿素和内源激素含量的影响

本文研究了在（25±1）℃下,气调包装和乙烯吸收剂处理对采后青梅果实叶绿素含量、内源激素IAA,GA3,ABA含量和乙烯释放量的影响及它们之间的关系。结果表明：气调包装果实叶绿素含量最高,其次是乙烯吸收剂处理的;各处理中气调包装果实的乙烯释放量始终很低,GA3含量较高,IAA和ABA含量则较低;对照果实的则相反,乙烯释放量很高,IAA和ABA含量较高,而GA3含量较低。乙烯吸收剂处理的处于二者之间。气调包装可以维持果实较高的GA3水平,降低ABA含量,保持较高的GA3／ABA值,抑制IAA和乙烯的生成,延缓梅果叶绿素的降解。     

FaMADS1和FaMADS2参与ABA调控的草莓果实成熟

本试验以‘红颜’草莓为材料,通过RT-PCR技术克隆得到FaMADS1和FaMADS2基因,并且用不同浓度脱落酸(abscisic acid, ABA)和其抑制剂去甲二氢愈创木酸(nordihydroguaiaretic acid, NDGA)处理脱绿期草莓果实,以探究FaMADS1和FaMADS2基因是否参与脱落酸调控的草莓果实成熟。结果表明,FaMADS1和FaMADS2基因序列在草莓不同栽培品种间高度保守,FaMADS1基因的表达变化随果实成熟呈现先增后降再增加的变化趋势,FaMADS2基因则呈现一个逐渐下降的趋势。虽FaMADS1和FaMADS2基因在草莓果实成熟中表达趋势并不一致,但外源ABA处理均会上调其表达,NDGA会下调其表达。草莓果实发育过程中内源ABA含量变化与FaMADS1和FaMADS2基因表达的相关性分析显示两者呈显著相关。由此说明,FaMADS1和FaMADS2参与了ABA调控的草莓果实成熟。     

北五味子体细胞胚发生过程中内源IAA、ABA和GA3含量的动态变化

以北五味子不同发育阶段的体细胞胚为材料,利用高效液相色谱法(HPLC)对其内源吲哚乙酸(IAA)、脱落酸(ABA)和赤霉素(GA3)含量进行了测定,探讨内源激素在体细胞胚正常发育过程中所具有的作用。在北五味子体细胞胚发生过程中,IAA和GA3含量均呈现先增加后降低趋势,ABA含量表现为先降低后增加趋势。IAA和ABA含量分别在球形胚阶段达到最大值和最小值,而GA3含量在心形胚阶段达到最大值。与正常体细胞胚相比,畸形胚中IAA和GA3含量高于各时期的正常胚状体,而ABA含量则显著低于其他各时期的正常胚状体。高水平的IAA在北五味子体细胞胚的发生阶段起重要的作用,而ABA在体细胞胚的成熟过程中起关键作用,GA3则与其体细胞胚的生长发育过程密切相关。但过高水平的IAA和GA3,以及过低水平的ABA会使体胚无法正常发育成熟,可能是引起畸形胚数量增加的主要原因之一。     

Exercise, dobutamine, and combined atropine, norepinephrine, and epinephrine compared

We compared the cardiovascular effects evoked in conscious dogs by 1) submaximal exercise; 2) infusion of dobutamine (40 micrograms X kg-1 X min-1); and 3) infusion of a combination of atropine (0.15 mg/kg), norepinephrine (0.19 micrograms X kg-1 X min-1), and epinephrine (0.05 micrograms X kg-1 X min-1). Myocardial O2 demand, as estimated by the double product (heart rate X systolic blood pressure), was similar during all three interventions. Cardiac output and heart rate increased significantly (P less than 0.05) during each of the three interventions. Arteriovenous O2 difference and total body O2 consumption, however, increased only during submaximal exercise. Although myocardial blood flow increased similarly during each of the three interventions, blood flow to skeletal muscle and the tongue increased only during exercise. Exercise and the combined infusion of atropine, norepinephrine, and epinephrine produced similar increases in blood flow to the diaphragm and similar decreases in blood flow to the stomach. These changes in blood flow were associated with appropriate changes in vascular resistance. Additionally, blood flow to the brain, kidney, adrenal glands, liver, and intestine did not change during any of the three interventions. Thus, in dogs, submaximal exercise, infusion of dobutamine, and infusion of a combination of atropine, norepinephrine, and epinephrine to evoke a given level of estimated myocardial O2 consumption produce similar increases in cardiac output, heart rate, and myocardial blood flow. In contrast, the changes in total body O2 consumption, arteriovenous O2 difference, regional blood flow, and regional vascular resistance that occur during each of these three interventions are different.     

Definitions,measurements, and classifications of stimuli,situations, and environments

A review is presented of issues relevant to the definition, measurement, and classification of stimuli, situations, and environments. Problems such as the lack of adequate definitions of concepts, error and bias in measurement procedures, confusion between measurement of a concept and measurement of its behavioral effects, and the lack of agreement among alternative measures are emphasized. It is suggested that concepts be defined in terms of objective characteristics while allowing for the study of the transactional relationship between organism and environment. The work of the ethologists in defining stimuli while studying their relationship to different organismic states and situational contexts is emphasized in this regard. Following Brunswik, it is also suggested that wherever possible there be a representative sampling of variables in natural settings. Note from the editors: From time to time, Human Ecology will publish a review article. Our first in this series is a review by a psychologist of basic definitional and conceptual problems in environmental studies.This paper was prepared while the author was a Visiting Research Fellow at the Educational Testing Service. The support of ETS and my colleagues in the Division of Psychological Studies is gratefully acknowledged. The review was also supported in part by a grant from the Rutgers University Research Council.     

Indians, Markets, and Rainforests: Theory, Methods, and Analysis

Indians, Markets, and Rainforests: Theory, Methods, and Analysis. Ricardo A. Godoy. New York: Columbia University Press, 2001. 274 pp.     

Synthesis,tautomerism, and antimicrobial,anti-HCV,anti-SSPE,antioxidant, and antitumor activities of arylazobenzosuberones

2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3a–i. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3a–i were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities.     

Lipid,lipoprotein, and apolipoprotein models: past,present, and future

Mones Berman's untimely death on 12 August 1982 put an end to his work in the development of theoretical biology. Arguments are examined, and it is concluded that a formal theory of lipoprotein metabolism flourished and expanded under the guidance of Dr. Berman. Not many scientists in the field of biology spend a major portion of their energies on theoretical work xxx was outstanding because of his early decision to follow the theoretical path.     

Pericytes: developmental, physiological, and pathological perspectives, problems, and promises

Pericytes, the mural cells of blood microvessels, have recently come into focus as regulators of vascular morphogenesis and function during development, cardiovascular homeostasis, and disease. Pericytes are implicated in the development of diabetic retinopathy and tissue fibrosis, and they are potential stromal targets for cancer therapy. Some pericytes are probably mesenchymal stem or progenitor cells, which give rise to adipocytes, cartilage, bone, and muscle. However, there is still confusion about the identity, ontogeny, and progeny of pericytes. Here, we review the history of these investigations, indicate emerging concepts, and point out problems and promise in the field of pericyte biology.