Characterization and mapping of a novel mutant sms1 (senescence and male sterility 1) in rice

Plant senescence plays diverse important roles in development and environmental responses.However,the molecular basis of plant senescence is remained largely unknown.A rice spontaneous mutant with the character of early senescence and male sterility (sms) was found in the breeding line NT10-748.In order to identify the gene SMS1 and the underlying mechanism,we preliminarily analyzed physiological and biochemical phenotypes of the mutant.The mutant contained lower chlorophyll content compared with the wild t...     

拟南芥白化突变体心口的基因定位与分析

EMS30是拟南芥经甲基磺酸乙酯（EMS）诱变得到的白化突变体。该突变体的叶绿体结构存在严重缺陷,同时伴随叶绿素缺失。遗传分析显示EMS30突变体的突变表型受隐性单基因控制。采用图位克隆的方法对EMS30突变基因进行定位的结果显示,该基因位于拟南芥第一条染色体的分子标记F21M12和F14N23之间的96kb区间内,该区间包含25个基因。通过生物信息学分析发现,该区间内有3个基因定位在叶绿体或与叶绿体发育相关。这些结果有助于该基因的克隆,为阐释叶绿体发育提供线索。     

转录因子C/EBPβ的翻译后修饰

CCAAT增强子结合蛋白β(CCAAT enhancer-binding proteinβ,C/EBPβ)是转录因子C/EBP家族的重要成员。它通过对靶基因转录的调节,参与细胞增殖与分化、肿瘤发生与凋亡、细胞周期调控等重要生命活动,同时这些功能受到磷酸化、乙酰化、泛素化等多种翻译后修饰的调控。本文综述近年来有关C/EBPβ的翻译后修饰的研究进展。这些研究不仅为人们认识C/EBPβ的调控机制提供了一个新的角度,同时也可能为肥胖及相关代谢疾病的发生和治疗提供新的理解。     

菲律宾海北部底质沉积中的深海介形类

对琉球群岛东侧的菲律宾海北部海区(27.0°-30.0°N,129.5°-135.5°E)水深1 666 m至6 616 m的123个表层沉积物样品进行了定量微体古生物学研究.仅在38个样品中发现介形类,主要分布在4 000 m以浅水深区.初步鉴定有21属35种,其中Krithe在样品中的出现率和丰度最高,其次常见的还...     

水稻储藏过程中淀粉黏度特性的变化

对水稻淀粉黏度特性特征值测定的统计分析表明：在避光自然温度储藏期间,不同类型稻谷淀粉黏度特征值均有明显的变化,各特征值在储藏1～5个月内变化较小,而6～7个月期间变化较大,大部分特征值变化差异达到显著或极显著水平。不同类型稻谷在储藏期间黏度特征值发生明显差异的时间点不同,粳糯类水稻品种在储藏期间发生明显差异的时间点明显早于粳稻和籼稻类。储藏时间与淀粉黏度特征值优化方程建立结果显示：与籼稻类品质变化关系密切的主要特征值为最高黏度（PKV）、崩解值（BDV）和峰值时间（PeT）,粳稻类为热浆黏度（HPV）、冷胶黏度（CPV）和回复值（CSV）,而粳糯类为PKV、BDV、CSV和起浆温度（PAT）。研究结果表明,通过RVA谱主要特征值来评价不同类型水稻品种稻谷耐储藏性具有可行性。     

外源24-表油菜素内酯对盐胁迫下茄子种子萌发和幼苗生理特性的影响

研究了150mmol·L^-1NaCI胁迫下,外源24-表油菜素内酯（EBR）对茄子种子萌发、幼苗生长和生理特性的影响。结果表明,0．05mg·L^-1外源EBR显著缓解150mmol·L^-1NaCI胁迫伤害,使茄子种子发芽率提高了8．23％,发芽势提高15．91％,发芽指数提高了17．23％,活力指数提高了44．29％;幼苗株高、根长和植株鲜重分别提高了56．67％、23．83％和56．68％;抗氧化酶（SOD、POD、CAT和APX）活性分别增加了13．75％、24．00％、28．64％和21．46％,脯氨酸和可溶性糖含量分别提高30．96％和23．66％;MDA含量、Ｏ产生速率分别降低了29．58％和14．80％。表明0．05mg·L^-1外源EBR能显著促进盐胁迫下茄子种子萌发和幼苗生长,明显缓解叶片氧化损伤,增强茄子的耐盐能力。     

激活视网膜水平细胞离子型谷氨酸受体抑制γ-氨基丁酸转运体电流(英文)

本工作在酶解分离的鲫鱼视网膜水平细胞上研究了AMPA受体对γ-氨基丁酸(γ-aminobutyric acid,GABA)转运体电流的调节作用。由1mmol/L GABA所诱导的GABA转运体电流被持续50s的AMPA(30μmol/L或3mmol/L)预灌流所抑制。在细胞内液中施加10mmol/L BAPTA可以减弱AMPA对GABA转运体电流的抑制效应。施加3mmol/L AMPA+3mmol/ LNMDA所引起的抑制效应和单独施加3mmol/L AMPA或3mmol/L NMDA所引起的抑制效应相仿。以上结果表明,和激活NMDA受体调节GABA转运体的机制一样,激活视网膜水平细胞上的AMPA受体可以通过胞内钙过程来抑制GABA转运体电流。     

Upland rice and lowland rice exhibited different P/P expression under water deficit and ABA treatment

Aquaporins play a significant role in plant water relations.To further understand the aquaporin function in plants underwater stress,the expression of a subgroup of aquaporins,plasma membrane intrinsic proteins(PIPs),was studied at boththe protein and mRNA level in upland rice(Oryza sativa L.cv.Zhonghan 3)and lowland rice(Oryza sativa L.cv.Xiushui63)when they were water stressed by treatment with 20% polyethylene glycol(PEG).Plants responded differently to20% PEG treatment.Leaf water content of upland rice leaves was reduced rapidly.PIP protein level increased markedlyin roots of both types,but only in leaves of upland rice after 10h of PEG treatment.At the mRNA level,OsPIP1;2,Os-PIP1;3,OsPIP2;1 and OsPIP2;5 in roots as well as OsPIP1;2 and OsPIP1;3 in leaves were significantly up-regulatedin upland rice,whereas the corresponding genes remained unchanged or down-regulated in lowland rice.Meanwhile,weobserved a significant increase in the endogenous abscisic acid(ABA)level in upland rice but not in lowland rice underwater deficit.Treatment with 60μM ABA enhanced the expression of OsPIP1;2,OsPIP2;5 and OsPIP2;6 in roots andOsPIP1;2,OsPIP2;4 and OsPIP2;6 in leaves of upland rice.The responsiveness of PIP genes to water stress and ABAwere different,implying that the regulation of PIP genes involves both ABA-dependent and ABA-independent signalingpathways during water deficit.     

水稻转录因子OsBP-73靶基因的初步筛选

OsBP-73是用酵母单杂交系统,以水稻蜡质基因(Wx)的顺式作用元件为诱饵,从水稻cDNA表达文库中筛选获得的转录因子。本文以OsBP-73基因为例介绍了用"下拉"(pull-down)方法筛选转录因子靶基因的一般步骤。将含有该基因DNA结合功能域的cDNA片段构建到原核表达载体上,并在大肠杆菌中诱导表达获得其蛋白p73。用纯化后的p73蛋白通过"下拉"实验对OsBP-73靶基因进行初步筛选,获得了22个阳性克隆,为进一步研究转录因子OsBP-73参与的水稻转录调控网络提供依据。