Subjects: Biology >> Botany >> Applied botany submitted time 2024-05-07 Cooperative journals: 《广西植物》
Abstract： Seedling is the most important stage during the life history of plant and plays a critical role in the forest regeneration. We studied the species composition seasonal dynamics and spatial distribution of tree seedlings in the 20 hm 2 Ailaosha n forest dynamics plot . The forest dynamics plot was built in a mid mountain moist evergreen broad leaved forest in the Ailaoshan. Within the 20 hm 2 plot, we established 450 seedling quadrats of size 1 m × 1 m . We investigated the species composition, seas onal recruitment, seasonal mortality and spatial distribution of tree seedlings for four years ( from 2019 to 2022). The results were as follows: 1 We recorded a total of 2 928 seedlings of 58 species belonging to 42 genera and 26 families. There were 817 recruits of 47 species and 1 181 dead seedlings of 50 species. (2) The i mportance val u e s of tree seedlings varied among different tree species across years . Symplocos ramosissima and Machilus bombycina were t he dominant species, with importan ce values con sistently in the top 2 in four years while the importan ce value of the pioneer species Viburnum cyclindricum decline d continuously (3) W e didn't find significant differences in species richness, average species richness in a quadrat, species diversity S hannon Wiener index, Simpson index) index), abundance, recruits, recruitment rate, mortality and mortality rate of tree seedlings between different seasons. 4 The majority of species exhibited restricted distribution within the plot, wh ile only a few species di splayed a broader distribution across the plot. Topography was found to determine the distribution and diversity of tree seedlings with higher species richness, density and diversity (Shannon Wiener index and Simpson index) in the flat topography compared to the ridge and valley of the plot . T hese findings suggest that we don't find significant differences in community composition, recruitment and mortality of tree seedlings between different seasons. Topography influences the spatial distribution and diver sity of tree seedlings. The present study reveals the dynamics of recruitment and mortality of tree seedlings and provide the theoretical basis for biodiversity conservation and forest management.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-12-19 Cooperative journals: 《广西植物》
Abstract： Suriana maritima (Surianaceae) is a coastal ornamental plant species distributing only on the South China Sea Islands in China, at present. In order to understand the ecological and biological characteristics of S. maritima, and provide a theoretical basis for its protection, development and utilization, we investigated the morphological and anatomical structure of stem and leaf, the antioxidant enzyme activity and osmotic adjustments contents in leaf of S. maritima, and nutrient element contents in leaf and the soil S. maritima growing on the Paracel Islands, by field investigation and sampling for analysis. The results showed that S. maritima have small and thick leaf, well-developed palisade tissue, and low stomatal density (8.64 n·mm-2), which make it easy to maintain water in the body and suitable for drought and high saline-alkali environment. The chlorophyll content (0.76 mg·g-1) of the leaf was low, the total antioxidant capacity (589.50 U·g-1) and proline content (1 123.64 μg·g-1) were high, indicating that S. maritima had high photosynthetic utilization efficiency and strong antioxidant capacity. Though the nutrient in natural growing soil was poor, the contents of organic carbon, nitrogen and phosphorus in leaf of S. maritima were relatively high (490.27, 18.10, and 3.81 g·kg-1, respectively), indicating a high nutrient utilization efficiency and good adaptability of S. maritima to poor soil. Therefore, S. maritima had a good adaptability to the environment of strong radiation, drought, high saline-alkali and poor soil on tropical coral islands, and could be used as a tool species for revegetation and landscaping on tropical coral islands.
Subjects: Biology >> Bioengineering submitted time 2018-12-17 Cooperative journals: 《中国生物工程杂志》
Abstract：摘要：PR结构域蛋白16(PR domain-containing 16,PRDM16)是棕色脂肪细胞分化过程的重要转录因子，其对维持棕色脂肪细胞的特殊形态特征及细胞功能具有重要的作用。PRDM16不仅能调控棕色脂肪细胞的分化，而且可能是脂肪细胞和肌细胞相互转化的“开关”，还与白色脂肪细胞的米色化过程相关。研究发现，人和家畜的PRDM16基因具有丰富的SNPs位点，这些SNPs位点与人类疾病和家畜生产性状之间存在着一定的相关性。鉴于PRDM16在脂肪分化和人类健康等方面的重要性，综述了近十几年来国内外研究者在PRDM16基因与蛋白的结构与功能、该基因与疾病和家畜经济性状的相关性等方面的研究成果，并展望了PRDM16的未来研究方向与在人类疾病治疗和动物性状改良方面的应用前景。
Subjects: Biology >> Bioengineering submitted time 2018-12-16 Cooperative journals: 《中国生物工程杂志》
Abstract：利用大孔吸附树脂DA-201为载体对海洋脂肪酶固定化，并探寻添加剂对固定化过程的影响。分别以NH4Cl、甘露糖和甘氨酸为添加剂，采用单因素和正交实验相结合的方法优化条件。结果显示，以NH4Cl为添加剂的最优条件：柠檬酸-柠檬酸钠缓冲液pH 6.0，固定化温度30℃，载体投放量0.5g，NH4Cl浓度为25mmol/L，固定化时间3.0h，酶活力达到115.27U/g；比不含有添加剂的固定化酶固定化效率提高47.42%。以甘露糖为添加剂最有条件：磷酸二氢钾-氢氧化钠缓冲液pH7.0，固定化温度35℃，载体投放量0.5g，甘露糖浓度10mmol/L，固定化时间4.5h；酶活力达到122.75U/g，比不含有添加剂的固定化酶固定化效率提高6.50%。以甘氨酸为添加剂的最优条件：磷酸二氢钾-氢氧化钠缓冲液pH7.0，固定化温度20℃，载体投放量0.5g，甘氨酸浓度为25mmol/L，固定化时间7.5h；酶活力达到141.69U/g，比不含有添加剂的固定化酶固定化效率提高26.12%。采用不同添加剂对大孔吸附树脂DA-201的吸附固定化过程有较大影响，可以极大的提高吸附效率；同时发现缓冲液类型、pH、温度、添加剂浓度和固定化时间等对DA-201树脂吸附脂肪酶有很大影响，对后续吸附固定化工业酶研究有较好的参考价值。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-10-26 Cooperative journals: 《广西植物》
Abstract：花部形态是马铃苣苔属属下划分和种间界定的关键性状，缺乏花器官的描述直接导致了一些存疑物种的存在。网叶马铃苣苔（Oreocharis rhytidophylla C. Y. Wu ex H. W. Li）自 1956 年最后被采集到并于 1983年发表，由于没有花的特征，在《中国植物志》 、《中国苦苣苔科植物》和“Flora of China”均存疑，但该种在随后的 60 余年间再无相关的采集记录。经过多年的跟踪调查，2017 年作者在其模式产地重新发现并采集了带花的凭证标本。根据已经采集到具花标本，我们确定这个种是个自然种，并基于新收集到的材料，补充描述了花的形态特征。网叶马铃苣苔的重新发现为探索其系统位置提供了重要的依据。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-07-23 Cooperative journals: 《广西植物》
Abstract： Stoichiometric homeostasis is one of the core concepts of ecological stoichiometry. It refers to the ability of an organism to maintain a given elemental composition in the body despite variation in the elemental composition of its environment or diet. It reflects the net outcome of many underlying physiological and biochemical adjustments as organisms respond to their surroundings. The homeostatic index (H) of plant can be estimated by measuring the nitrogen and phosphorus contents and N:P ratio in plant and soil. In general, the homeostasis of plants is weaker than that of animals, with a larger variety of homeostasis. Stoichiometric homeostasis is an important mechanism in maintaining ecosystem structure, function, and stability. The homoeostatic species tend to have high and stable biomass; and ecosystems dominated by more homoeostatic species have higher productivity and greater stability. Therefore, the homeostasis is considered to be an important index to measure species competitiveness. Studies of stoichiometric homeostasis of plant will help us to understand the adaptation strategies and ecological adaptability of plants to the environment, as well as the relationship between plant ecological stoichiometry homeostasis and ecosystem functions. However, there are few studies on the internal stability of plant ecological stoichiometry. Previous research showed that the stoichiometric homeostasis characteristics of different plant species or functional groups were different. There were differences in stoichiometric homeostasis among different growth stages, different organs of the same species, as well as different nutrient elements. This paper reviews the concept of stoichiometric homeostasis, the estimation of plant homeostatic index (H), the stoichiometric homeostasis characteristics of different plant species or functional groups, different organs and growth stages and different elements, as well as linking plant stoichiometric homoeostasis with ecosystem structure, functioning and stability. Based on the obtained achievements and the current study, we put forward some perspectives of plant stoichiometric homoeostasis for future research to be conducted with an aim to promote this discipline of research in China.
Subjects: Biology >> Bioengineering submitted time 2018-03-13 Cooperative journals: 《中国生物工程杂志》
Abstract：脂酰-酰基载体蛋白（fatty acyl-acyl carrier protein, acyl-ACP）是多种生物合成途径中的酰基供体。因供给限制，体外研究常用类似物acyl-CoA替代，而CoA部分和ACP有较大差异，限制了相关酶对底物识别的认识。因此稳定获得大量acyl-ACP是体外研究相关酶的催化机制及其代谢途径的关键。研究以holo-ACP和C4-C18链长脂肪酸为底物，在哈氏弧菌acyl-ACP合成酶（Vibrio harveyi acyl-ACP synthetase, VhAasS）催化下合成不同碳链长度的acyl-ACP；通过高效液相色谱(HPLC)方法，确定不同碳链长度acyl-ACP的合成产率。结果表明：碳链为C4-C14的acyl-ACP产率均高于90.0%，16:0-ACP产率为85.9%，18:1-ACP产率仅为25.7%。通过加入Li+优化反应体系，16:0-ACP、18:1-ACP的产率达90.0%。进一步优化扩大反应体系可稳定获得20 mg以上acyl-ACP；最后，把合成的acyl-ACP应用到甘油-3-磷酸酰基转移酶催化的反应体系中。不同链长acyl-ACP的规模化合成研究，为体外研究相关酶的催化机制提供重要基础。
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加谷氨酰胺（Gln）对断奶仔猪不同阶段生长性能的影响，以及其对脂多糖（LPS）诱导肠道损伤后断奶仔猪血清生化指标和生长性能的影响。选用24头28日龄健康的“杜×长×大”三元杂交断奶仔猪，随机分为3组，每组8个重复，每个重复1头猪。对照组和LPS组饲喂基础饲粮，Gln+LPS组饲喂添加了1%的外源性Gln的基础饲粮；在试验第22、25、28、30天，LPS组和Gln+LPS组腹腔注射100 μg/kg BW LPS，对照组则注射相同剂量的生理盐水。试验期30 d。结果表明：1）LPS处理前（试验第1~21天），与对照组相比，Gln+LPS组显著提高了试验第1~7天断奶仔猪的平均日采食量（ADFI）和平均日增重(ADG)（P0.05）。3）LPS组断奶仔猪的小肠长度显著低于对照组和Gln+LPS组（P0.05）。4）与对照组相比，Gln+LPS组断奶仔猪的血清高密度脂蛋白胆固醇（HDLC）含量和碱性磷酸酶（ALP）活性显著降低（P0.05）；Gln+LPS组和LPS组断奶仔猪的血清免疫球蛋白M（IgM）含量显著提高（P<0.05）。由此可见，饲粮中添加1%的Gln能够显著提高仔猪断奶后第1~7天的生长性能，之后效果不明显。饲粮中添加1%的Gln能够调节应激仔猪的血清生化指标，改善其生长性能和小肠长度，从而缓解仔猪断奶应激。
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验以大肠杆菌型脂多糖(LPS)建立氧化应激模型，探讨了谷氨酰胺（GLN）对断奶仔猪氧化应激的影响。选用24头28日龄的健康三元（杜×长×大）断奶仔猪，随机分成3组，每组8个重复，每个重复1头猪。对照组和应激组饲喂基础饲粮，GLN组饲粮在基础饲粮中添加1% GLN，试验期为30 d。在试验第22、25、28和30天，应激组和GLN组仔猪分别按每千克体重腹腔注射100 μg LPS，对照组仔猪腹腔注射相同剂量的灭菌生理盐水，第30天进行前腔静脉采血并屠宰采取所需肠道样品，检测氧化应激相关指标。结果显示：1）LPS攻毒前各组血清抗氧化能力指标均无显著差异(P>0.05)。LPS攻毒后，应激组血清丙二醛(MDA)含量显著高于对照组(P<0.05)；GLN组血清MDA含量和超氧化物歧化酶(SOD)活性显著低于应激组和对照组(P<0.05)。2）LPS攻毒后，在十二指肠黏膜中，GLN组过氧化氢酶（CAT）和锌铜超氧化物歧化酶(CuZuSOD)基因相对表达量显著高于应激组(P<0.05)。在空肠黏膜中，GLN组CAT、锰超氧化物歧化酶(MnSOD)、谷胱甘肽过氧化物酶1(GPX1)和谷胱甘肽过氧化物酶4(GPX4)基因相对表达量显著高于对照组和应激组(P<0.05)，对照组GPX4基因相对表达量显著高于应激组(P<0.05)。在回肠黏膜中，GLN组和应激组CAT基因相对表达量显著低于对照组(P<0.05)，GPX4基因相对表达量显著高于对照组(P<0.05)；GLN组MnSOD基因相对表达量显著高于对照组和应激组(P<0.05)，CuZnSOD基因相对表达量显著高于对照组(P<0.05)。结果表明，GLN在一定程度上可以缓解断奶仔猪因LPS引起的氧化应激，以期为实际生产中减少氧化应激提供一定的理论基础。
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