菠萝果实发育相关RFD1基因的克隆及表达

Blast菠萝果实不同发育时期的cDNA文库测序结果,并用信息生物学软件和相关网站进行拼接和分析,设计特异引物RT-PCR．得到一个2750bp、编码761个氨基酸的全长基因序列,命名NRFD1。预测该蛋白是一个亲水性、且具有多个磷酸化位点的分泌性蛋白,可能位于叶绿体中。半定量PCR分析发现RFD1基因表达量在果实发育期不断增加,70d达到最高：而在70d果实的不同部位并没有显著差异性,仅果实外部略有增高。     

Cd~（2＋）胁迫诱导烟草悬浮细胞脯氨酸积累的生化途径及外源脯氨酸对Cd~（2＋）胁迫下H_2O_2产生的抑制作用

Cd~（2＋）可提高烟草悬浮细胞脯氨酸的含量,顺序上调脯氨酸合成关键酶鸟氨酸转氨酶（OAT）、精氨酸酶、△~1-吡咯啉-5-羧酸合成酶（P5CS）和谷氨酸脱氢酶（GDH）的活性,降低脯氨酸降解关键酶脯氨酸脱氢酶（ProDH）的活性,表明Cd~（2＋）胁迫诱导烟草细胞脯氨酸的积累是脯氨酸合成的鸟氨酸途径和谷氨酸途径顺序激活、而脯氨酸降解途径显著抑制的综合结果。此外,Cd~（2＋）能导致烟草细胞H_2O_2的快速产生及H_2O_2产生相关酶（质膜NADPH氧化酶、细胞壁多胺氧化酶及共价结合与离子结合细胞壁过氧化物酶）活性升高和脂质过氧化产物丙二醛（MDA）增加,导致烟草细胞的氧化胁迫。外源脯氨酸预处理显著抑制了Cd~（2＋）诱导的烟草细胞H_2O_2的产生与MDA的增加,减轻了Cd~（2＋）诱导的氧化胁迫。而脯氨酸抑制Cd~（2＋）诱导的H_2O_2产生可能是由于脯氨酸抑制了H_2O_2产生相关酶的活性所致。     

磁化水对小麦种子萌发、幼苗生长和生理特性的生物学效应

为研究磁化水对作物的生物学效应,本文详细分析了磁化水处理对小麦种子萌发、幼苗生长和生理特性的影响。研究结果显示：磁化水处理小麦的种子发芽参数与对照相比无显著差异;磁化水处理对小麦的株高、根长、地上部和根部鲜重等生长参数也无显著影响;同样,磁化水处理在叶片色素含量、可溶性糖、可溶性蛋白质含量、含水量、细胞汁液渗透势等重要生理特征参数方面也未显示出显著差异。此外,磁化水并未显著影响小麦叶片的光合作用。综上所述,磁化水处理对小麦种子萌发和幼苗生长无明显的生物学效应。     

外源茉莉酸甲酯对非生物胁迫下蝴蝶兰幼苗叶绿素荧光和抗氧化指标的影响

通过盆栽试验,研究了外源茉莉酸甲酯（MeJA）处理对低温、干旱和极端高温胁迫下蝴蝶兰幼苗叶绿素荧光参数和抗氧化指标的影响。结果表明,较高浓度的MeJA（150和200μmol·L-1）提高了非生物胁迫下蝴蝶兰幼苗叶片最大光化学效率（Fv/Fm）和实际光化学效率（ΦPSII）,降低了叶片相对电导率,还使得超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性升高,丙二醛（MDA）含量降低。表明MeJA作为一种生物调节剂,一定浓度的处理对蝴蝶兰幼苗抗逆性的提高具有明显效果。     

Bioenergy Plants: Hopes,Concerns and Prospectives

There are major concerns over both the security of energy supplies (declining supplies and political control) and the environmental costs associated with energy generation and use.The global consumption of carbon-containing fossil fuels for     

C_4 Plants as Biofuel Feedstocks: Optimising Biomass Production and Feedstock Quality from a Lignocellulosic Perspective

The main feedstocks for bioethanol are sugarcane (Saccharum officinarum) and maize (Zea mays),both of which are C4 grasses,highly efficient at converting solar energy into chemical energy,and both are food crops.As the systems for lignocellulosic bioethanol production become more efficient and cost effective,plant biomass from any source may be used as a feedstock for bioethanol production.Thus,a move away from using food plants to make fuel is possible,and sources of biomass such as wood from forestry and ...     

Pretreatment with H_2O_2 Alleviates Aluminum-induced Oxidative Stress in Wheat Seedlings

Hydrogen peroxide(H2O2) is a key reactive oxygen species(ROS) in signal transduction pathways leading to activation of plant defenses against biotic and abiotic stresses.In this study,we investigated the effects of H2O2 pretreatment on aluminum(Al) induced antioxidant responses in root tips of two wheat(Triticum aestivum L.) genotypes,Yangmai-5(Al-sensitive) and Jian-864(Al-tolerant).Al increased accumulation of H2O2 and O2r· leading to more predominant lipid peroxidation,programmed cell death and root elon...     

Allelic Analyses of the Arabidopsis YUC1 Locus Reveal Residues and Domains Essential for the Functions of YUC Family of Flavin Monooxygenases

Flavin monooxygenases(FMOs) play critical roles in plant growth and development by synthesizing auxin and other signaling molecules.However,the structure and function relationship within plant FMOs is not understood.Here we defined the important residues and domains of the Arabidopsis YUC1 FMO,a key enzyme in auxin biosynthesis.We previously showed that simultaneous inactivation of YUC1 and its homologue YUC4 caused severe defects in vascular and floral development.We mutagenized the yuc4 mutant and screene...     

Rice OsRAD21-2 is Expressed in Actively Dividing Tissues and its Ectopic Expression in Yeast Results in Aberrant Cell Division and Growth

Rad21 and its meiotic counterpart Rec8,the key components of the cohesin complex,are essential for sister chromatid cohesion and chromosome segregation in mitosis and meiosis,respectively.In contrast to yeast and vertebrates,which have only two RAD21/REC8 genes,the rice genome encodes four Rad21/Rec8 proteins.Here,we report on the cloning and characterization of OsRAD21-2 from rice(Oryza sativa L.).Phylogenetic analysis of the full-length amino acids showed that OsRad21-2 was grouped into the plant-specific...     

WBC27,an Adenosine Tri-phosphate-binding Cassette Protein,Controls Pollen Wall Formation and Patterning in Arabidopsis

In flowering plants,the exine components are derived from tapetum.Despite its importance to sexual plant reproduction,little is known about the translocation of exine materials from tapetum to developing microspores.Here we report functional characterization of the arabidopsis WBC27 gene.WBC27 encodes an adenosine tri-phosphate binding cassette(ABC) transporter and is expressed preferentially in tapetum.Mutation of WBC27 disrupted the exine formation.The wbc27 mutant microspores began to degenerate once rel...