Responses of soil labile organic carbon and water-stable aggregates to reforestation in southern subtropical China

中国南亚热带土壤易分解有机碳和水稳性团聚体对造林的响应 造林被认为可以提高土壤碳稳定性并促进土壤碳累积。然而,实验结果差异很大,造林在提高土壤碳稳定性方面的作用仍存在争议。因此,在森林生态系统中不同土壤碳库对造林如何响应目前尚不清楚。基于此,本文对亚热带地区的尾叶桉林(Eucalyptus urophylla)、厚荚相思林(Acacia crassicarpa)、 红锥林(Castanopsis hystrix)、10树种混交林和自然恢复草坡等5种不同林型的土壤碳组分进行了研究,评估其不同土层(0–10、10–20、20–40 和40–60 cm)中的土壤易分解有机碳(容易被高锰酸钾氧化的有机碳ROC和土壤可溶性有机碳DOC)及土壤团聚体相关的碳对造林的响应。实验结果表明,造林(与自然恢复草坡比较)和林型并没有显著影响土壤ROC浓度,而自然恢复草坡土壤的DOC浓度在4个土层中均最高。0–10 cm土层中各径级的土壤团聚体其碳(C)浓度均是红锥林最高。此外,在任一土层中,林型对不同径级土壤水稳性团聚体比例的影响均不显著。但是土壤深度显著改变土壤团聚体的分布,0–20 cm土层主要为>0.25 mm粒径的团聚体,20–60 cm土层则是0.053–2 mm粒径的团聚体占主导。这些结果显示造林和林型影响土壤DOC 和团聚体C,而且它们相比于ROC对造林的响应更为敏感。研究发现,与自然恢复相比,人工林降低了土壤DOC浓度,暗示它可能会减少土壤C的淋溶损失。此外,红锥林能够通过物理保护提高表土层中土壤碳的稳定性。本研究为关注土壤碳汇功能时的中国南亚热带地区造林树种选择提供了有价值的信息。     

Timing and abundance of sporangia production and zoospore release influences the recovery of different Phytophthora species by baiting

Analysis of soil samples using High Throughput Sequencing (HTS) frequently detects more Phytophthora species compared with traditional soil baiting methods. This study investigated whether differences between species in the timing and abundance of sporangial production and zoospore release could be a reason for the lower number of species isolated by baiting. Stems of Eucalyptus marginata were inoculated with ten Phytophthora species (P. nicotianae, P. multivora, P. pseudocryptogea, P. cinnamomi, P. thermophila, P. arenaria, P. heveae, P. constricta, P. gondwanensis and P. versiformis), and lesioned sections for each species were baited separately in water. There were significant differences between species in timing of sporangia production and zoospore release. P. nicotianae, P. pseudocryptogea, P. multivora and P. thermophila released zoospores within 8–12 h and could be isolated from lesioned baits within 1–2 days. In contrast, P. constricta did not produce zoospores for over 48 h and was only isolated 5–7 days after baiting. P. heveae and P. versiformis did not produce zoospores and were not recovered from the baits. When species were paired in the same baiting tub, those that produced zoospores in the shortest time were isolated most frequently, while species slow to produce zoospores, or which produced them in lower numbers, were isolated from few baits or not at all. Thus, species differences in the timing of sporangia production and zoospore release may contribute to the ease of isolation of some Phytophthora species when they are present together with other Phytophthora species in an environmental sample.     

长江中下游岸带(宜昌-铜陵段)湿生植物的群落构建机制研究

沿长江中下游（宜昌-铜陵段）13座城市共37个位点,分别于丰水期和枯水期对岸带的湿生植物进行调查,从物种和系统发育2个维度研究群落的构建机制,并结合环境和空间因子探讨其驱动因素。结果显示：（1）丰水期湿生植物群落的α多样性高于枯水期,且丰水期α多样性主要与水分条件呈正相关,而枯水期则主要与温度和土壤总氮含量有关。（2）丰水期的系统发育结构指数呈聚集趋势,暗示生境过滤起着主导作用,而枯水期的NRI（net relatedness index）和NTI（nearest taxon index）呈不同趋势,暗示存在近期的群落分化。（3）群落的α多样性在物种层面和系统发育层面存在显著关联性,其多样性水平可在一定程度上互为表征。（4）长江中下游沿岸湿生植物群落的构建机制在不同时期存在差异,丰水期的群落构建是环境筛选和扩散限制共同作用的结果,且以环境筛选作用占主导,而枯水期的群落构建仅在物种层面受一定程度环境筛选作用的影响。（5）大生境的温度变化、微生境的土壤水分和养分条件是影响长江中下游岸带湿生植物群落差异的主要驱动因素。该研究结果可为长江中下游岸带湿地生态系统的管理和保护提供科学支持。     

Cyanidin-3- O -β-glucopyranoside Protects Myocardium and Erythrocytes from Oxygen Radical-mediated Damages

The cyanidin-3- O - &#103 -glucopyranoside (C-3-G) antioxidant capacity towards reactive oxygen species (ROS)-mediated damages was assessed in tissue and cells submitted to increased oxidative stress. In the isolated ischemic and reperfused rat heart, 10 or 30 &#119 M C-3-G protected from both lipid peroxidation (66.7 and 94% inhibition of malondialdehyde (MDA) generation in 10 and 30 &#119 M C-3-G-reperfused hearts, respectively, in comparison with control reperfused hearts) and energy metabolism impairment (higher ATP concentration in 10 and 30 &#119 M C-3-G-reperfused hearts than in control reperfused hearts). These effects were associated to C-3-G permeation within myocardial cells, as indicated by results obtained in the isolated rat heart perfused for 30 min in the recirculating Langendorff mode under normoxia with 10 and 30 &#119 M C-3-G. Protective effects were exerted, in a dose-dependent manner, by C-3-G also in 2 mM hydrogen peroxide-treated human erythrocytes. With respect to MDA formation, an apparent IC 50 of 5.12 &#119 M was calculated for C-3-G (the polyphenol resveratrol used for comparison showed an apparent IC 50 of 38.43 &#119 M). The general indications are that C-3-G (largely diffused in dietary plants and fruits, such as pigmented oranges very common in the Mediterranean diet) represents a powerful natural antioxidant with beneficial effects in case of increased oxidative stress, and at pharmacological concentrations it is able to decrease tissue damages occurring in myocardial ischemia and reperfusion.     

Association between Gene Polymorphism of Manganese Superoxide Dismutase and Prostate Cancer Risk

Manganese superoxide dismutase (MnSOD) is the most effective antioxidant enzyme in mitochondria and protects cells from reactive oxygen species‐induced oxidative damage. The aim of this study was to investigate the association between MnSOD Ala‐9Val gene polymorphism and prostate cancer (PCa) risk in Turkish men with prostate cancer. 33 patients with PCa and 81 control individuals were included in the study. We observed an association between MnSOD Ala/Ala frequency and a higher PCa risk. In addition, we found that the increased risk of early‐onset PCa (under age of 65) in the men homozygous for Ala allele was higher than the men homozygous for Val allele. However, we determined that MnSOD Ala‐9Val genotype was not associated with the aggressiveness of the disease. The results of our study suggest that MnSOD Ala/Ala genotype may influence on early‐onset of PCa patients, but no effect on subsequent development of the disease in Turkish men. However, our study has a limitation that is small numbers of individuals for cases and controls. Therefore, the presented study limited our statistical power to fully investigate the gene polymorphism on cancer risk. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:213‐218, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21472     

The Impact of Different Antioxidant Agents alone or in Combination on Reactive Oxygen Species,Antioxidant Enzymes and Cytokines in a Series of Advanced Cancer Patients at Different Sites: Correlation with Disease Progression

In the present study we tested the ability of different antioxidant agents, used alone or in combination, to reduce the reactive oxygen species (ROS) levels and to increase the glutathione peroxidase (GPx) activity. Moreover, we tested the ability of such antioxidant agents to reduce the serum levels of proinflammatory cytokines IL-6 and TNF &#102 . Fifty-six advanced stage cancer patients with tumors at different sites were included in the study: they were mainly stage III (12.5%) and stage IV (82.1%). The study was divided into two phases. In the 1 st phase 28 patients were divided into five groups and a single different antioxidant agent was administered to each group. The selected antioxidant agents were: alpha lipoic acid or carboxycysteine-lysine salt, amifostine, reduced glutathione, vitamin A plus vitamin E plus Vitamin C. In the 2 nd phase of the study 28 patients were divided into five groups and a combination of two different antioxidant agents was administered to each group. The antioxidant treatment was administered for 10 consecutive days. The patients were studied at baseline and after antioxidant treatment. Our results show that all single antioxidants tested were effective in reducing the ROS levels and three of them in increasing GPx activity, too. Among the combinations of antioxidant agents, three were effective in reducing ROS, while three were effective in increasing GPx activity (arm 4 was effective in both instances). Comprehensively, the "antioxidant treatment" was found to be effective both on ROS levels and GPx activity. Moreover, the antioxidant treatment was able to reduce serum levels of IL-6 and TNF &#102 . Furthermore, a correlation was shown between the Eastern Cooperative Oncology Group Performance Status of patients and blood levels of ROS, GPx activity, serum levels of proinflammatory cytokines.