高山植物唐古特红景天（Rhodiola algida Var.tangutica）抗冻蛋白的研究

抗冻蛋白（AFP）或热滞蛋白（THP）最早是从极区鱼和昆虫中发现的一类特殊蛋白质，其共同特性是能阻止体液内冰核的形成和生长，降低体液的冰点，使其冰点低于熔点（热滞效应）。近几年的研究表明，AFP在某些植物、细菌、真菌中也存在。生长在极端低温环境中的高山植物体内是否也存在AFP，据我们掌握的资料，还未见这方面的报道。为此，我们选择了青海高原海拔4000米高山生长的唐古特红景天为实验材料，并在这种植物中发现了抗冻蛋白。主要实验结果概括如下： 1. 唐古特红景天叶片有很强的抗冻性，可耐受-26.5 ℃的冰冻温胁迫。在北京地区夏季（7月）驯化20天后，半致死温度（LT_(50)）升高为-15.5 ℃。叶片质外体蛋白抽提液有明显的热滞效应（0.2 ℃），在AFP中存在糖基。SDS-PAGE分析表明，质外体AFP为分子量在43-85KD范围内的五条多肽。 2. 光镜组织化学切片显示，在红景天叶片中存在蛋白质量丰富的细胞;电镜细胞化学研究揭示，在细胞壁外层及细胞间隙中分布着明显的经钌红特异染色的糖蛋白，这种糖蛋白因环境温度升高而减少。结合前述的实验结果，确认这种细胞壁外层及细胞间隙中的糖蛋白，即抗冻蛋白。 3. 以唐古特红景天叶片为外植体，在MS+BA_2+NAA_(0.2)固体培养基上可诱导出黄绿色，松脆愈伤组织。愈伤组织细胞在同样成分的液体培养基中培养获得成功。在悬浮培养液中可检测到分泌蛋白的存在。经SDS-PAGE分析表明，经低温锻炼或ABA诱导后，细胞分泌蛋白的多肽谱带数增加。与此相对应的是，细胞的抗冻能力也明显提高。PAS染色揭示，多肽中均含有糖基。 4. 通过测定热滞值，确信细胞分泌蛋白是具有抗冻活性的糖蛋白。

Toxicity of copper sulphate on some haematological parameters of a freshwater teleost Cyprinus carpio var. communis

Haematological changes in a freshwater teleost, Cyprinus carpio var. communis, exposed to acute and sublethal toxicity of copper sulphate were studied. During the acute treatment, erythrocyte and leucocyte count, and haemoglobin content increased, whereas during the sublethal treatment, erythrocyte count and haemoglobin content decreased and leucocyte count increased.

Responses of plasma transaminase activity in Cyprinus carpio var. communis to mercury toxicity

The present study reports the behavioural and enzymological responses in a freshwater teleost fish, Cyprinus carpio var. communis, exposed to acute and sublethal toxicities of mercuric chloride. During acute treatment, significant behavioural changes like erratic swimming, excess mucus secretion and increased opercular movements were noticed. During acute and sublethal treatments, both aspartate amino transferase and alanine amino transferase activity increased throughout the study period. Comparing the treatments, the changes in enzyme activities were found high in acute treatment and all the values were significant at 5% level. The above findings can be used as non-specific biomarkers of environmental pollutants.

Responses of Cyprinus carpio var. communis to Cyhalothrin, a pyrethroid insecticide

Haematological and biochemical profiles in a freshwater teleost, Cyprinus carpio var. communis, exposed to sub-lethal toxicity of the insecticide cyhalothrin were studied. During the treatment, erythrocyte count, haemoglobin content and protein content decreased, whereas leucocyte count and glucose level increased. The data are discussed in relation to the significance of haematological and biochemical changes as non-specific biomarkers against anthropogenic stress.

One new flavanoid and Anti-HIV active constituents from boussingaultia gracilis miers var. pseudobaselloides bailey

Boussingaultia gracilis Miers var. pseudobaselloides Bailey (Basellaccae) is a folk medicine used as an analgesic and supplements, only a few research was reported on the chemical constituents of this plant. This paper presented its chemical and anti-HIV

Lignans with Anti-HIV Activity from Schisandra propinqua var. sinensis

Fourteen new lignans, tiegusanins A-N (1-14), together with 13 known compounds were isolated from the aerial parts of Schisandra propinqua var. sinensis. The structures and absolute configurations of 1-13 were established using a combination of spectrosco

Effect of high dietary starch levels on the growth performance, blood chemistry and body composition of gibel carp (Carassius auratus var. gibelio)

An 8-week growth trial was carried out in a semi-recirculation system to investigate the effect of high dietary starch levels on the growth performance, blood chemistry, starch utilization and body composition of gibel carp (Carassius auratus var. gibelio). Five isonitrogenous and isocarloric experimental diets were formulated to contain different starch levels (24%, 28%, 32%, 36% and 40% respectively). Triplicate groups of fish (24 fish per tank with an average body weight, of 8.5 g) were assigned to each diet. The results showed that dietary carbohydrate levels significantly affected the growth performance, hepatopancreatic lipid content, pyruvate kinase (PK) activity and whole-body lipid content. Growth performance, body crude lipid and plasma glucose concentrations showed a decreasing trend with an increase in dietary starch from 24% to 40%. Pyruvate kinase activities and hepatopancreatic lipid content showed an increasing trend with the dietary starch increasing from 24% to 32%, and then a decreasing trend with the dietary starch increasing from 32% to 40%. No significant difference in the hepatopancreatic hexokinase (HK) activity, plasma triglyceride contents, body crude protein, ash and calcium (Ca) and phosphorus (P) contents was observed between different treatments. In conclusion, higher dietary starch levels (32-40%) significantly (P < 0.05) decreased the growth of gibel carp in the present study.

Photosynthetic parameters of sexually different parts of Porphyra katadai var. hemiphylla (Bangiales, Rhodophyta) during dehydration and re-hydration

Physiological data from extreme habitat organisms during stresses are vital information for comprehending their survival. The intertidal seaweeds are exposed to a combination of environmental stresses, the most influential one being regular dehydration and re-hydration. Porphyra katadai var. hemiphylla is a unique intertidal macroalga species with two longitudinally separated, color distinct, sexually different parts. In this study, the photosynthetic performance of both PSI and PSII of the two sexually different parts of P. katadai thalli during dehydration and re-hydration was investigated. Under low-grade dehydration the variation of photosystems of male and female parts of P. katadai were similar. However, after the absolute water content reached 42%, the PSI of the female parts was nearly shut down while that of the male parts still coordinated well and worked properly with PSII. Furthermore, after re-hydration with a better conditioned PSI, the dehydrated male parts were able to restore photosynthesis within 1 h, while the female parts did not. It is concluded that in P. katadai the susceptibility of photosynthesis to dehydration depends on the accommodative ability of PSI. The relatively lower content of phycobiliprotein in male parts may be the cause for a stronger PSI after severe dehydration.

New life cycles of Porphyra katadae var. hemiphylla in culture

Porphyra katadae Miura var. hemiphylla Tseng et T. J. Chang, a species distributed around the Liaodong and Shandong Peninsulas of China, produces gametophytes from late winter to early spring. These are monoecious with male and female reproductive tissues in distinct halves or sectors. Vegetative tissues from sectors expected to differentiate into sexual tissue were cultured in the laboratory. Male and female reproductive organs, as well as conchocelis and blades, were differentiated from these tissues. The male and female reproductive tissues were in patches and mixed on the cultured tissue pieces. This was quite different from the wild-type sectored individuals. The F-1 conchospore germlings also produced monospores, carposporangia, spermatangia and conchocelis. These carposporangia and spermatangia were in patches and were mixed on the F-1 fronds. The results imply that P. katadae var. hemiphylla is possibly sex-differentiated rather than sex-determined. This is the first report of such a dimorphic life history in the genus Porphyra.

Geographic variation in the leaf essential oils of Juniperus sabina L. and J-sablina var. arenaria (E.H. Wilson) Farjon

The composition of the leaf oils from seven populations of J. sabina L., one population of Juniperus sabina var. arenaria (E. H. Wilson) Farjon were examined for their geographic variation. In addition, the leaf oils of J. chinensis L. and J. davurica Pall. were compared to J. sabina. Juniperus sabina var. arenarla, the sand loving juniper, oil was found to be very similar to that of J. davurica, Mongolia, and J. sabina, on sand dunes in Mongolia. This suggests that J. sabina var. arenaria might be conspecific with J. davurica. Farjon's move (2001) of J. sabina var. arenaria out of J. chinensis is supported. Considerable differentiation was found in populations of J. sabina from the Iberian peninsula. Cedrol, citronellol, safrole, trans-sabinyl acetate, terpinen-4-ol and beta-thujone were found to be polymorphic in several populations.

甘蓝(Brassica oleracea L. var. capitata L.)富集铊的环境地球化学研究

通过对甘蓝进行品种差异、亚细胞分析、根际分泌物提取污染土壤中的铊、营养元素添加以及野外甘蓝样品采集分析，结合地球化学理论。分析了甘蓝对铊吸收富集的机理，并得出以下几点结论： (1) 甘蓝叶、根及茎对铊的吸收存在着明显差异，表明在面临土壤铊胁迫时，叶是铊的主要储存部位，而根和茎主要起到了转运作用。甘蓝中铊含量的升高导致了对钙和镁吸收能力的提高。不同品种甘蓝之间的吸收能力差别不大，通过选择种植对铊吸收能力小的甘蓝来控制铊的食物链危害是不可行的。此外，还应该避免在高铊土壤地区种植甘蓝。 (2) 高达92%的铊存在于甘蓝叶细胞液组分中，表明细胞液组分是铊在甘蓝叶细胞中的一个重要储存部位。但是在不同品种甘蓝叶中，铊的亚细胞分布形态没有显著差异，在甘蓝面对铊胁迫时，其叶细胞器组分中铊含量始终维持很低的含量。甘蓝对铊的解毒机制很可能就是通过在细胞内的区隔化作用(compartmentalization)，把进入体内的铊结合到细胞液组分以及细胞壁上，从而减少了铊对重要细胞器官的损伤。铊在甘蓝叶各亚细胞组分中的分配与常量元素存在一定的关系。在甘蓝叶细胞内，Tl+往细胞液组分中的传输很有可能是通过Na+/K+/2Cl–联合传输机制、Ca2+活化的钾离子通道以及一些需Mg2+或Mn2+的K+活化酶完成的。需要Mn2+参与的K+活化酶可能对于铊往细胞器中的转移起到了主导作用。在细胞壁中，很可能Ca2+活化的K+通道或者是某些特定的需要Mn2+的K+活化酶对铊的迁移或固定起了影响作用。 (3) 随着氮、磷、钾营养元素的加入，甘蓝地上部的生物量有一定程度的上升。影响主次因素依次均为氮>磷>钾。随着氮、磷、钾营养元素的加入，甘蓝地上部和地下部的铊含量并没有上升，而是有一定程度的下降。甘蓝地上部中铊含量的影响主次因素依次为磷>氮>钾，甘蓝地下部中铊含量的影响主次因素依次为氮>磷>钾。氮、磷、钾营养元素的加入都提高了甘蓝对铊的吸收量。甘蓝对铊吸收量的影响主次因素依次均为氮>磷>钾。因此我们认为，氮，磷，钾的加入显著提高了甘蓝生物量和铊的吸收量，但是随之而来的生物稀释效应，导致了甘蓝地上部和地下部含量的降低。运用铊累积量来判断营养元素对甘蓝吸收铊的影响更为客观和可靠。 (4) 通过对比蒸馏水和根际分泌物提取液对污染土壤中铊的提取能力，发现甘蓝根际分泌物提取液(root exudates)对污染土壤中的铊具有明显的活化作用。提取液的pH和土壤铊的提取率存在一定的正相关(R2=0.1659)，也就是说提取液的pH与其对污染土壤中铊的提取能力成正比。但是甘蓝体内各部分铊含量与其根际分泌物提取液对土壤铊的提取率没有任何关系，表明大量的植物非必需元素铊进入甘蓝后，并没有对其根际分泌物的产生任何影响。土壤pH越高，生长的甘蓝的根际分泌物提取液对土壤提取率就越高，甘蓝分泌物提取液对铊的提取率升高可以补偿由于土壤pH升高而造成的水溶态存在的铊减少。 (5) 铊在甘蓝叶片和叶柄中的分布状况为老叶叶片>新叶叶片>老叶叶柄>新叶叶柄，表明叶柄也是运输铊的一个重要器官。但是叶柄对铊的转运能力并没有茎那么强烈，而叶片才是甘蓝中最主要的铊储存部位。铊在根、茎、老叶和新叶中亚细胞的分布均为细胞液>>细胞壁>细胞器，这和前期室内温室培养甘蓝叶片中的分布结果是一致的。根据植物采矿经济理论的计算结果，很显然甘蓝可以成为土壤铊污染的植物修复和采矿的备选对象。