香石竹DcMAPK1和DcMAPK2的克隆及功能初#br# 步分析

 分离了香石竹（Dianthus caryophyllus）两个促分裂原活化蛋白质激酶（mitogen-ac-tivated protein kinase,MAPK）基因cDNA 全长,分别命名为DcMAPK1 和DcMAPK2,其中DcMAPK1 与拟南 芥AtMAPK6 高度同源。DcMAPK1 在香石竹花瓣衰老过程表达增加,乙烯处理显著促进其表达,瞬时抑 制DcMAPK1 后切花瓶插寿命显著延长。而DcMAPK2 在花瓣衰老过程中组成型表达,乙烯处理对其表达 无显著影响,瞬时抑制DcMAPK2 对切花瓶插寿命无显著影响。     

干旱胁迫对银杏衰老期叶片生理生化特性的影响

以银杏5 a生盆栽实生苗为材料,通过自然干旱处理,研究干旱对银杏衰老期叶片部分生理指标的影响。结果表明:与对照相比,处理组叶绿素含量下降;电导率和MDA含量上升;SOD和CAT的活力先上升后下降;脯氨酸逐渐积累,可溶性蛋白含量呈现先上升后下降的趋势。说明随着干旱胁迫的加剧,引起了膜脂氧化加剧,加快了银杏叶片的衰老。     

Silver thiosulphate: An experimental tool in plant science

The anti-ethylene properties of silver thiosulphate (STS) are reviewed. Because of the specificity of the silver ion in STS, ethylene sensitive and non-sensitive components can be distinguished in studies on the effects of ethylene on plant growth and development. The ability of STS to prevent wilting in cut flowers and petal drop in potted flowering plants, and to induce sex transformations in female plants, together with its relative ease of application and low cost per plant, are arguments in favour of using STS in commercial horticulture.     

烟叶成熟过程相关基因变化及其叶绿素降解

烤烟叶片成熟过程与衰老是烟草发育的重要阶段,是一个复杂和高度调控的过程,涉及衰老相关基因的调控表达和叶绿体的分解,也是烟草质量和品质形成的关键时期,因此其成为烟草生产和研究的重要时段。介绍了烟叶衰老过程相关基因的表达变化和叶绿素分解的过程,为从分子水平定义烟叶的成熟度提供理论依据。     

三唑酮延缓青稞离体叶片衰老的研究

以青稞叶片为试材,对其进行黑暗诱导衰老,研究了三唑酮处理对青稞离体叶片叶绿素a、叶绿素b、水溶性蛋白质、非水溶性蛋白质、丙二醛(MDA)含量、Chl a/b值和过氧化物酶(POD)、超氧化歧化酶(SOD)、过氧化氢酶(CAT)活性的影响。结果显示,在青稞离体叶片衰老过程中,叶绿素a、叶绿素b、Chl a/b值与水溶性、非水溶性蛋白质含量均不断下降,丙二醛含量、POD活性上升,SOD和CAT活性降低。三唑酮处理延缓叶绿素a、叶绿素b、Chl a/b值与非水溶性蛋白质含量的下降,抑制丙二醛含量、POD活性的上升,阻碍SOD活性降低,对水溶性蛋白质和CAT作用不明显。表明三唑酮具有减轻青稞离体叶片膜脂过氧化的能力和延缓叶片衰老的作用。     

ZmNAP基因对玉米抗衰老及产量性状的调控效应

为了探索ZmNAP基因在调控玉米抗衰老及产量性状等方面的作用,根据已知的ZmNAP基因cDNA序列构建玉米Ubi启动子控制下的ZmNAP的RNA干扰载体pTCK303ihpZmNAP,并通过农杆菌介导的方法对ZmNAP基因进行遗传转化。结果表明:ZmNAP转基因玉米植株在叶片滞绿、籽粒千粒重等方面较野生型植株(WT)有明显优势,转基因植株比野生型植株千粒重提高15%～30%。ZmNAP基因在玉米育种中具有重要的应用价值。     

Relationship between grain filling duration and leaf senescence of temperate rice under high temperature

High temperature during grain filling period has been reported to decrease the grain filling duration, leading to the lower grain weight and yield of rice. Two experiments in the phytotron and field were carried out to test the hypothesis that the leaf senescence of rice plants may determine the grain filling duration under high temperature. In the phytotron experiment in 2008, rice plants of a japonica cultivar “Ilpumbyeo” were subjected to three minimum/maximum (mean) temperature regimes of 11/19 (15), 17/25 (21), and 23/31 °C (27 °C). In the field experiment, rice seedlings of the same rice cultivar were transplanted on May 6th and June 19th in 2009 and the mean temperatures during the grain filling period were 24.4 and 21.9 °C, respectively. Both experiments revealed consistently that high temperature increased the rates of grain filling and leaf senescence while it reduced the durations of them. However, grain filling was terminated earlier than complete leaf senescence, the time gap being greater at higher temperature. In addition, the fraction of dry matter partitioning to the leaf sheath + culm resumed to increase following the termination of grain filling under high temperature, indicating that leaves were still maintaining photosynthetic capacity and supplying assimilates into the other plant tissues except grain even after the termination of grain filling. These findings suggest that an early termination of grain filling in temperate rice under high temperature was not resulted from the lack of assimilate owing to the early leaf senescence but from the loss of sink activity owing to the earlier senescence of panicle.     

Ethylene

Abstract

Ethylene is a simple gaseous hormone that is involved in many aspects of plant growth and development. Two physiological responses that are commonly controlled by ethylene, fruit ripening and flower senescence, have been given the most significant attention in terms of crop improvement using the tools of modern plant molecular biology and biotechnology. Fortunately, the wealth of research on ethylene biosynthesis and signaling pathway has been providing tools for the genetic control of ethylene effects. Today, manipulation of ethylene biosynthesis and signaling is one of the most promising approaches to improve crops through genetic engineering. In this review we will discuss current status and future directions of transgenic techniques to control ethylene effects with a primary focus on flower senescence.     

肥力对冬小麦顺序和非顺序衰老茎同化物积累和转运的影响

【目的】研究在适肥和高肥水平下,顺序和非顺序衰老茎顶三叶和地上器官同化物积累及转运特性,为阐明小麦叶片非顺序衰老的生理生化机制提供理论指导。【方法】以生育后期(05-16)非顺序衰老发生率较高的小麦品种温麦19、豫麦19和兰考矮早8为材料,设高肥(尿素225kg/hm2,磷酸二氢铵337kg/hm2,春季追施尿素112kg/hm2)和适肥(尿素150kg/hm2,磷酸二氢铵225kg/hm2,春季追施尿素75kg/hm2)2个肥力水平,在小麦扬花期(04-22)、叶色倒置现象发生时期(05-16)和成熟期,分别采集参试小麦品种正置茎和倒置茎,测定2个肥力水平下顶三叶的绿叶面积及其叶片、叶鞘、地上营养器官、穗和籽粒的干质量,比较正置茎和倒置茎顶三叶各指标的差异。【结果】在适肥和高肥条件下,参试小麦品种正置茎绿叶面积均表现为旗叶倒二叶倒三叶,而倒置茎绿叶面积表现为倒二叶旗叶倒三叶。正置茎旗叶干物质积累量与倒二叶接近,均大于倒三叶;倒置茎倒二叶干物质积累量显著大于旗叶和倒三叶。正置茎和倒置茎顶三叶叶鞘干物质积累量均表现为旗叶叶鞘倒二叶叶鞘倒三叶叶鞘。正置茎地上营养器官花前同化物转运量、转运率和对籽粒的贡献率均大于倒置茎,而正置茎地上营养器官花后同化物转运量和对籽粒的贡献率均低于倒置茎。倒置茎籽粒千粒质量均显著高于正置茎。与适肥水平相比,高肥水平可以延缓叶片衰老,增加营养器官干物质积累量,减少营养器官花前同化物向籽粒的转运,提高千粒质量。【结论】在高肥和适肥条件下,参试小麦品种均有叶片非顺序衰老的发生,且生育后期小麦叶片的非顺序衰老有利于籽粒的充实。     

不同浓度KT预处理液对干藏洋桔梗切花保鲜的影响

为分析KT预处理液对洋桔梗(Eustoma russellianum)切花的保鲜效果,采用不同浓度的KT预处理液处理洋桔梗,干藏后检测鲜切花的瓶插寿命、可溶性糖、花青素、SOD、MDA等生理生化指标。结果表明,干藏洋桔梗切花使用KT预处理液处理后SOD活性增强,MDA含量降低,可溶性糖含量升高,可延缓花青素降解和延长切花瓶插寿命,且提高了洋桔梗切花的观赏品质。其中,2%蔗糖+40 mg/L KT+80 mg/L柠檬酸+200 mg/L 8-HQ配方对洋桔梗切花的保鲜效果最佳。