Physiological Mechanisms of Al Resistance in Higher Plants

Aluminum (Al) ion is toxic to plant growth, while the resistance to Al toxicity varies widely among plant species. Accumulating evidence has shown that organic acids play an important role in both internal and external detoxification of Al. Two patterns of Al-induced secretion of organic acid anions have been characterized in the external detoxification. Involvement of ABA or protein phosphorylation in the activation of anion channel in Pattern I and less contribution of organic acid metabolism in Pattern II have been reported. Recently, gene or quantitative trait locus (QTL) for Al-activated secretion of organic acid anions has been identified. Other mechanisms of Al resistance are also reported such as pH increase in the rhizosphere. The formation of a non-toxic Al complex with organic acids or other chelators and sequestering these complexes in the vacuoles play an important role in internal detoxification of Al in Al-accumulating plants.     

几种重金属对刺参体腔细胞超氧阴离子(O2-)产生的影响

测定重金属(Zn2 、Pb2 、Cd2 、Cu2 )对刺参体腔细胞吞噬过程中超氧阴离子(O2-)产生的影响。结果表明:Cu、Zn、Pb、Cd均能抑制刺参体腔细胞吞噬过程中超氧阴离子(O2-)的产生。低浓度重金属离子Zn2 (1、5、10mg.L-1),Pb2 (0.5mg.L-1),Cd2 (0.05mg.L-1)处理刺参体腔细胞能使其吞噬过程活性氧产生增加;高浓度重金属离子Zn2 (50、100、200mg.L-1),Pb2 (1、5、10、50、100mg.L-1),Cd2 (0.5、5、10、50、100mg.L-1)处理能明显地抑制刺参体腔细胞吞噬过程中的超氧阴离子(O2-)的产生,Cu2 在浓度为0.1mg.L-1时就开始对超氧阴离子(O2-)的产生抑制,随着浓度的加大,抑制作用明显。     

干巴菌子实体内伴生真菌的研究

干巴菌子实体形态较伞菌类真菌予实体特殊。据分析,干巴菌子实体内含有地上植被凋落物,这些凋落物是干巴菌子实体内件生真菌茵的携带者,采用常规的表面消毒剂不易把它们杀灭,因此干巴菌内的伴生真菌存在,给干巴菌菌种的分离和鉴定造成了干扰和困惑。首批报道的干巴菌子实体内件生真茵有。毛霉(Mucor sp.),赤霉(Gibberella sp. ),交链孢霉(Alternaria sp.),拟盘多毛孢霉(Pestalotiopsis sp.),肠茸毛菌(Enterobryus sp.)双足囊茵(Dipodascus sp.)等六属六种真茵。     

龙岩国家森林公园云顶茶园空气负离子浓度的测定与评价

在介绍空气负离子产生、作用及评价方法的基础上,对龙岩国家森林公园云顶茶园空气负离子浓度进行测定、评价,结果表明,云顶茶园景区各景点空气负离子浓度平均值为60.7万个.cm-3,正离子浓度达到68.7万个.cm-3,CI值平均为539.1,q值平均为1.132;各景区空气负离子平均浓度是龙岩市区空气负离子浓度的100多倍。     

饲料中阿散酸的高效液相色谱检测技术的研究

建立了饲料中阿散酸的高效液相色谱-离子交换分离-紫外检测的定量分析方法。用25mmol/L的氢氧化钠溶液作为提取剂,在50℃水浴中提取30min,以40mmol/L磷酸氢二钠-甲醇(960∶40,V/V)为流动相等度洗脱,在阴离子色谱分离柱上进行分离,244nm处检测,12min内分离阿散酸。饲料中阿散酸的平均回收率达到92.4%～99.6%,相对标准偏差小于4.9%。阿散酸的检出限为0.2mg/L,定量限为1mg/kg。     

Dietary cation–anion difference of Timothy (Phleum pratense L.) as influenced by application of chloride and nitrogen fertilizer

The effectiveness of forages to prevent post‐calving hypocalcaemia, when used as a feed source for non‐lactating dairy cows, can be predicted by the dietary cation–anion difference (DCAD). Three to four weeks before calving, the ration of non‐lactating dairy cows should have a DCAD around ?50 mmol_c kg^?1 DM. In an experiment, swards, based on Timothy (Phleum pratense L.), were used to (i) evaluate the impact of two types (CaCl₂ and NH₄Cl) and four application rates of chloride fertilizer per season (0, 80, 160 and 240 kg Cl ha^?1) in combination with two N application rates (70 and 140 kg N ha^?1) on mineral concentrations and DCAD in the herbage, and (ii) determine the economically optimal rate of chloride fertilizer (Cl_op) for DCAD in herbage. Chloride and N fertilizers were applied in the spring and, after the first harvest in 2003 and 2004 at four locations that differed in K content of their soils. Two harvests were taken during each year. Averaged across N‐fertilizer application rates, harvests and locations, the highest rate of chloride fertilizer increased chloride concentration in herbage by 8·5 g kg^?1 dry matter (DM) and decreased DCAD in herbage by 190 mmol_c kg^?1 DM to values as low as ?9 mmol_c kg^?1 DM. Both types of chloride fertilizer had the same effect on chloride concentration and DCAD in herbage and had no effect on DM yield. When no chloride fertilizer was applied on soils with a high content of available K, application of N fertilizer increased DCAD in herbage by 47 mmol_c kg^?1 DM at both harvests. Herbage DCAD was lower in summer than in spring by 47–121 mmol_c kg^?1 DM depending on the location. Application of chloride fertilizer can effectively lower the DCAD of Timothy‐based herbages; the economically optimal rate of chloride fertilizer in the spring varied from 78 to 123 kg Cl ha^?1, depending on soil K and chloride contents and expected DM yield.     

分析化学实验中含铬废水的处理

对分析化学实验中产生的含铬废水,选择沉淀法与阴离子交换树脂法相结合的方法进行处理,使处理后废水的铬含量远小于国家排放标准。将其引入学生的实验课与毕业论文选题中,以增强学生的环保意识与解决实际问题的能力。     

沙枣提取物清除自由基能力的研究

[目的]研究沙枣（Elaeagnus angustifolia L.）清除自由基的能力。[方法]以沙枣果实为材料,通过超声波、离心等方式,采用水、50%乙醇、70%乙醇、90%乙醇、95%乙醇、无水乙醇、丙酮、乙酸乙酯等溶剂提取清除自由基成分,应用水杨酸法和光照核黄素法分别测定其清除羟自由基和超氧阴离子自由基的能力。[结果]通过超声波和离心结合的方式,采用70%乙醇对沙枣果肉进行提取,所得到的提取液对羟自由基及超氧自由基的清除作用最佳,其中,对羟自由基的清除率高于河北大枣和维生素E。[结论]该研究为沙枣的保健作用机理研究提供了参考,并为其开发利用提供基本资料。     

Reactive oxygen species scavenging activities and inhibition on DNA oxidative damage of dimeric compounds from the oxidation of (−)-epigallocatechin-3-O-gallate

The dimeric catechins dehydrotheasinensin A (2) and theacitrin C (3) were prepared from the oxidation of (−)-epigallocatechin-3-O-gallate (EGCG, 1), and their antioxidant activity was investigated using a chemiluminescence (CL) method in vitro. Both compounds showed significant inhibitory effects on reactive oxygen species (O₂⁻, H₂O₂ and •OH) and DNA oxidative damage, with 2 being more potent than 3 and EGCG itself.     

高效阴离子色谱-脉冲安培检测法分析食用菌中海藻糖、甘露醇和阿糖醇

采用高效阴离子色谱-脉冲安培检测法(HAPEC-PAD)测定17种食用菌中海藻糖、甘露醇和阿糖醇含量.结果表明:阿糖醇、海藻糖和甘露醇的线性范围分别为239.62～1.25、59.41～0.15、148.29～5.00μg/mL,检出限分别为0.41、0.04、.11 μg/mL,定量限分别为1.14、0.10和5.79μg/mL;17种食用菌中,香菇(Lentinula edodes)和猴头菌(Hericium erinaceus)中阿糖醇含量较高,茶树菇(Agrocybe aegerita)、刺芹侧耳(Pleurotus eryngii)、鲍鱼侧耳(Pleurotus abalonus)、松口蘑(Tricholoma matsutake)、蛹虫草(Cordyceps militaris)中海藻糖含量较高,姬松茸(Agaricus blazei)、鸡油菌(Cantharellus cibarius)、金顶侧耳(Pleurotus citrinopileatus)、冬虫夏草(Cordyceps sinensis)中甘露醇含量较高;该项检测技术分离效果好、样品测定时不需要衍生化处理、检测时间短,是测定食用菌中功能性寡糖和糖醇类物质的有效方法.