Multiple forms and specificity of coniferyl alcohol dehydrogenase from cambial regions of higher plants

Alcohol dehydrogenases of 89 species of plants, from the Bryophyta, Pteridophyta, Gymnosperms and Angiosperms were examined by starch gel electrophoresis for their substrate and coenzyme specificities. High activities and multiple bands were observed with EtOH and NAD in most species. The same, but weaker banding patterns were also observed with benzyl alcohol and salicin. When coniferyl alcohol was used as substrate, activity was found only with NADP as coenzyme and the resulting bands were distinct from those obtained with the other substrates. Most plants tested had only one or occasionally a second coniferyl alcohol dehydrogenase band. Salix species were an exception, with multiple bands found in each of the species tested.     

Identification of novel acetylcholinesterase inhibitors: Indolopyrazoline derivatives and molecular docking studies

The synthesis of novel indolopyrazoline derivatives (P1-P4 and Q1-Q4) has been characterized and evaluated as potential anti-Alzheimer agents through in vitro Acetylcholinesterase (AChE) inhibition and radical scavenging activity (antioxidant) studies. Specifically, Q3 shows AChE inhibition (IC₅₀: 0.68 ± 0.13 μM) with strong DPPH and ABTS radical scavenging activity (IC₅₀: 13.77 ± 0.25 μM and IC₅₀: 12.59 ± 0.21 μM), respectively. While P3 exhibited as the second most potent compound with AChE inhibition (IC₅₀: 0.74 ± 0.09 μM) and with DPPH and ABTS radical scavenging activity (IC₅₀: 13.52 ± 0.62 μM and IC₅₀: 13.13 ± 0.85 μM), respectively. Finally, molecular docking studies provided prospective evidence to identify key interactions between the active inhibitors and the AChE that furthermore led us to the identification of plausible binding mode of novel indolopyrazoline derivatives. Additionally, in-silico ADME prediction using QikProp shows that these derivatives fulfilled all the properties of CNS acting drugs. This study confirms the first time reporting of indolopyrazoline derivatives as potential anti-Alzheimer agents.     

Differential inter- and intra-specific defense induction in Lupinus by Myzus persicae feeding

Experiments were conducted to investigate the potential induction of plant defenses by Myzus persicae Sulzer (Homoptera: Aphididae) feeding on five lupin, Lupinus spp. (Leguminosae), varieties with well‐characterized levels of aphid resistance. Myzus persicae feeding on L. angustifolius and L. luteus varieties induced genotype‐specific changes in their host that were not consistent with the level of aphid resistance or the plant species. The plant responses were systemically detected by apterous and alate forms of the aphids. Chemical assays revealed no induction of oxidizing enzyme (catalase, peroxidase, or polyphenol oxidase) activity, serine or cystein proteinase inhibitors, or soluble phenolics in any of the five varieties tested following 3 days of feeding by 10 or 30 aphids. However, there were significant differences among the five lupin varieties in the levels of peroxidase and polyphenol oxidase activity, proteinase inhibitors, and soluble phenolics.     

The digestive gland of the Southern Dumpling Squid (Euprymna tasmanica): structure and function

The cephalopod digestive gland plays an important role in the efficient assimilation of nutrients and therefore the fast growth of the animal. The histological and enzymatic structure of Euprymna tasmanica was studied and used in this experiment to determine the dynamics of the gland in response to feeding. The major roles of the digestive gland were secretion of digestive enzymes in spherical inclusions (boules) and excretion of metabolic wastes in brown body vacuoles. High levels of trypsin, chymotrypsin and α-amylase, low levels of α-glucosidase and negligible carboxypeptidase activity were produced by the gland. There was no evidence of secretion of digestive enzymes in other organs of the digestive tract. Within 60 min of a feeding event, the gland produced increasing numbers of boules to replace those lost from the stomach during the feeding event. Initially, small boules were seen in the digestive cells, they increased in size until they are released into the lumen of the gland where they are transported to the stomach. There was no evidence of an increase in activity of digestive enzymes following a feeding event, despite structural changes in the gland. However, there was large variation among individuals in the level of digestive enzyme activity. A negative correlation between boule and brown body vacuole density suggested that the large variation in enzyme activity may be due to the digestive gland alternating between enzyme production and excretion.     

真菌源激发子对采后葡萄果皮抗性产生的诱导

利用细胞壁提取法从葡萄采后致病菌Alternaria alternate(Fr．)Keissl中提取出激发子。在采前一周用激发子处理葡萄,研究激发子诱导葡萄采后抗病效果。结果表明：葡萄经激发子处理后,果皮内与抗病有关的过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性显著增强,酚类物质和木质素含量也显著提高,贮藏期自然发病率和发病指数降低,其中以125μg·mL-1处理效果最好,果实发病率和发病指数比对照降低500％左右。     

Photosynthesis and carbon metabolism in plantain (Musa AAB) plantlets growing in temporary immersion bioreactors and during ex vitro acclimatization

Summary The photosynthetic capacity changes and the main enzymatic systems related to carbon metabolism were investigated during the in vitro culture of plantain shoots (Musa AAB cv. CEMSA 3/4) in temporary immersion bioreactors (TIB) and their subsequent acclimatization. The maximal rate of photosynthesis (Pn), transpiration, and the activity of the carbon metabolism enzymes phosphoenolpyruvate carboxylase (PEPC), acid invertase (AI), pyruvate kinase (PK) and sucrose phosphate synthase (SPS) were measured every 7 d during the 21 d of elongation in TIB, and the following 42 d of acclimatization. Sucrose content in the liquid medium and in the leaves was also determined. The most significant changes in plant growth were observed during acclimatization. During the in vitro stage photosynthesis was limited (4–6 μmol CO₂m⁻²s⁻¹); the photosynthetic rate however increases rapidly and significantly as soon as in vitro culture is over during acclimatization. PEPC activity increased during the whole evaluation period. The highest levels were achieved around days 42 and 56. PK and SPS activities were optimal during the first weeks in acclimatization (28–35 d), while AI increased at the beginning of the elongation phase (7 d), and later at the end of the acclimatization (49–63 d). The relationships between morphological parameters, photosynthetic capacity of the plantlets and the carbon metabolism enzymes during both phases of the culture are discussed.     

Oxidative stress in digestive gland and gill of the brown mussel (Perna perna) exposed to air and re-submersed

Mussels Perna perna were exposed to air for 24 h showing a clear increase in the levels of lipid peroxidation and oxidative DNA damage, measured as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo). The levels of lipid peroxidation increased both in the digestive gland and gills, while oxidative DNA damage increased only in the gills. After the 24 h of air exposure, mussels were re-submersed for a period of 3 h, leading values to return to a pre-aerial exposure levels. Control animals were kept immersed during the whole period. Several antioxidant and complementary enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), glutathione S-transferase (GST) and the levels of total glutathione (Total GSH) were assayed in a second set of experiments where one group of mussels were exposed to air for 18 h and other to 1 h re-submersion after 18 h aerial exposure. Only a 52% increase in the glutathione S-transferase activity was observed in the digestive gland, which remained elevated to about 40% after 1 h re-submersion, showing that defense systems can be modulated even during oxygen deprivation in P. perna. The DNA and lipid oxidative damage observed after aerial exposure indicates that mussels face an oxidative challenge, and are able to counteract such an “insult” as values of lipid peroxidation and DNA damage returned to control values after 3 h re-submersion.     

3种念珠藻多糖对自由基的清除作用

研究了地木耳（Nostoc commune）、葛仙米（N．sphaerohies）和发菜（N．flagelliforme）3种念珠藻多糖对自由基的清除作用。结果表明,3种念珠藻多糖对超氧阴离子自由基和羟自由基具有很强的清除作用,且呈量效关系,地木耳清除超氧自由基作用最强,最高清除率达72．3％,葛仙米和发菜分别为46．7％、35．5％;发菜清除羟自由基效果最强,最高清除率达74．3％,葛仙米和地木耳清除率分别为49．0％、46．7％;3种念珠藻多糖对DPPH自由基的清除作用不显著。     

AFLP分子标记技术的改进

对AFLP技术的限制性内切酶组合进行了改进。以两个低频酶组合代替传统的高频酶与低频酶组合进行分子标记筛选,结果表明,采用低频酶组合(EcoRⅠ PstⅠ)产生的条带比传统酶切组合(EcoRⅠ MseⅠ和PstⅠ MseⅠ)要少且分布不均匀,多集中在150~800bp之间,条带信号强度要大,多态性明显得到提高,分子标记筛选成功率也得到了提高,而且其成本更低的特点有利于AFLP技术在我国的进一步推广普及。