The relationship between green roofs and urban biodiversity: a systematic review

Biodiversity and Conservation - As a form of green infrastructure, green roofs can enhance urban biodiversity by providing complex vegetation structures, supplying increased foraging and roosting...     

云南省爬行动物名录和地理区划更新

云南省作为中国生物多样性最高的省份, 其详实的物种本底资料对我国生物多样性研究和保护具有重要意义。本文在前期研究的基础上, 结合实体标本, 汇总编制了云南省现生、原生爬行动物更新名录。截至2021年12月31日, 云南省记录爬行动物25科82属235种, 其中龟鳖目4科12属16种, 有鳞目蜥蜴亚目6科20属72种, 蛇亚目15科50属147种。较《云南两栖爬行动物》确认新增82种, 存疑收录21种, 移除23种。基于先前云南省爬行动物区划和更新后的物种分布信息, 将云南省爬行动物地理分为6个动物地理区, 即滇西北横断山区、滇西山地区、滇南山地区、滇东南山地区、滇中高原区以及滇东北山地区; 其中滇西北横断山区、滇西山地区、滇中高原区和滇东南山地区的范围与先前研究相比有所调整。结合调整后的爬行动物地理区划, 对物种分布、物种特有性、受威胁状况等给出了统计结果。云南省爬行动物特有物种、国内仅见于云南的非特有物种数量较多, 受威胁等级高。建议今后继续加大分类学研究投入, 对滇西北、滇中特有爬行动物分布集中的区域积极开展栖息地保护工作, 同时在最新调整的《国家重点保护野生动物名录》基础上, 定期组织专家研讨, 对《云南省省级重点保护动物名录》提出更新建议。     

Universal stress protein in Malus sieversii confers enhanced drought tolerance

Journal of Plant Research - Drought is an important environmental factor that can severely affect plant growth and reproduction. Although many genes related to drought tolerance have been studied...     

Baseline sensitivity and control efficacy of fluazinam against Sclerotinia sclerotiorum in Henan Province,China

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a devastating disease in Henan Province, of the main rapeseed production areas in China. Fluazinam belongs to the broad‐spectrum phenylpyridinamine fungicides, which have high activity in inhibiting the mycelial growth of S. sclerotiorum. In this study, 191 field isolates were obtained from different oilseed rape fields in Henan Province, before being exposed to fluazinam in 2015. The baseline sensitivity of S. sclerotiorum to fluazinam was established. The effective concentration for 50% inhibition of mycelial growth (EC₅₀) ranged from 0.0019 to 0.0337 μg/ml, and the mean EC₅₀ value was 0.0084 ± 0.0055 μg/ml. The range of the frequency distribution was narrow. The results of a cross‐resistance assay revealed no cross‐resistance between fluazinam and carbendazim, dimethachlone, boscalid or fludioxonil. Field efficacy tests showed that the control efficacies of fluazinam (50% WG) applied at 150, 225 and 300 g ai ha^?1 were 67%, 73% and 88%, respectively. In contrast, the control efficacies of boscalid (50% WG) and carbendazim (50% WP) applied at 225 and 1,500 g ai ha^?1 were 71% and 52%, respectively.     

DNA end recognition by the Mre11 nuclease dimer: insights into resection and repair of damaged DNA

The Mre11–Rad50–Nbs1 (MRN) complex plays important roles in sensing DNA damage, as well as in resecting and tethering DNA ends, and thus participates in double-strand break repair. An earlier structure of Mre11 bound to a short duplex DNA molecule suggested that each Mre11 in a dimer recognizes one DNA duplex to bridge two DNA ends at a short distance. Here, we provide an alternative DNA recognition model based on the structures of Methanococcus jannaschii Mre11 (MjMre11) bound to longer DNA molecules, which may more accurately reflect a broken chromosome. An extended stretch of B-form DNA asymmetrically runs across the whole dimer, with each end of this DNA molecule being recognized by an individual Mre11 monomer. DNA binding induces rigid-body rotation of the Mre11 dimer, which could facilitate melting of the DNA end and its juxtaposition to an active site of Mre11. The identified Mre11 interface binding DNA duplex ends is structurally conserved and shown to functionally contribute to efficient resection, non-homologous end joining, and tolerance to DNA-damaging agents when other resection enzymes are absent. Together, the structural, biochemical, and genetic findings presented here offer new insights into how Mre11 recognizes damaged DNA and facilitates DNA repair.     

Protein expression patterns in two Spiraea species in response to cold treatment

We analyzed the different cold-resistance species Spiraea trichocarpa Nakai and Spiraea bumalda ‘Goldmound’ for low-temperature protein expression, protein types identification, and investigated the cold resistance mechanisms under different levels of low temperature by two-dimensional gel electrophoresis (2-DE) and mass spectrometry. An average of 668 and 559 protein spots were detected by 2-DE of S. bumalda ‘Goldmound’ and S. trichocarpa Nakai, respectively, under different low-temperature treatments. Matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy identified 48 proteins, with varying expression, related to metabolism, amino acid synthesis, transportation, stress responses and oxidation–reduction reactions. The results showed that the photosynthesis of S. bumalda ‘Goldmound’ had been affected, enzymes (RuBisCO large and small subunits) involved in the Calvin cycle were up- and down-regulated, and ATP synthase in photophosphorylation was down-regulated. Cytosolic malate dehydrogenase expression weakened in the TCA cycle, while amino acid synthesis strengthened. The activity of four antioxidant enzymes (superoxide dismutase [Cu–Zn], L-ascorbate peroxidase, glutathione peroxidase and peroxidase) was reduced under varying low temperatures. Enzymes (ribulose-bisphosphate carboxylase and RuBisCO small chain precursor) involved in the photosynthesis of S. trichocarpa Nakai showed obvious up- and down-regulation under low temperatures. Cold treatment influenced the photosynthesis of S. trichocarpa Nakai and S. bumalda ‘Goldmound’, but the results showed significant differences between the two species, which were supposed to the fact that low temperature modified the metabolic mechanisms and led to the weaker cold resistance in S. bumalda ‘Goldmound’ than in S. trichocarpa Nakai.     

Nutrient restriction induces failure of reproductive function and molecular changes in hypothalamus–pituitary–gonadal axis in postpubertal gilts

People on a diet to lose weight may be at risk of reproductive failure. To investigate the effects of nutrient restriction on reproductive function and the underlying mechanism, changes of reproductive traits, hormone secretions and gene expressions in hypothalamus–pituitary–gonadal axis were examined in postpubertal gilts at anestrus induced by nutrient restriction. Gilts having experienced two estrus cycles were fed a normal (CON, 2.86 kg/d) or nutrient restricted (NR, 1 kg/d) food regimens to expect anestrus. NR gilts experienced another three estrus cycles, but did not express estrus symptoms at the anticipated fourth estrus. Blood samples were collected at 5 days’ interval for consecutive three times for measurement of hormone concentrations at the 23th day of the fourth estrus cycle. Individual progesterone concentrations of NR gilts from three consecutive blood samples were below 1.0 ng/mL versus 2.0 ng/mL in CON gilts, which was considered anestrus. NR gilts had impaired development of reproductive tract characterized by absence of large follicles (diameter ≥ 6 mm), decreased number of corepus lutea and atrophy of uterus and ovary tissues. Circulating concentrations of IGF-I, kisspeptin, estradiol, progesterone and leptin were significantly lower in NR gilts than that in CON gilts. Nutrient restriction down-regulated gene expressions of kiss-1, G-protein coupled protein 54, gonadotropin-releasing hormone, estrogen receptor α, progesterone receptor, leptin receptor, follicle-stimulating hormone and luteinizing hormone and insulin-like growth factor I in hypothalamus–pituitary–gonadal axis of gilts. Collectively, nutrient restriction resulted in impairment of reproductive function and changes of hormone secretions and gene expressions in hypothalamus–pituitary–gonadal axis, which shed light on the underlying mechanism by which nutrient restriction influenced reproductive function.     

Diazoxide Pretreatment Prevents Aβ1–42 Induced Oxidative Stress in Cholinergic Neurons Via Alleviating NOX2 Expression

The aggregation and accumulation of amyloid-β (Aβ) plays a significant role in the pathogenesis of Alzheimer’s disease. Aβ is known to increase free radical production in neuronal cells, leading to oxidative stress and cell death. Diazoxide (DZ), a highly selective drug capable of opening mitochondrial ATP-sensitive potassium channels, has neuroprotective effects against neuronal cell death. However, the mechanism through which DZ protects cholinergic neurons against Aβ-induced oxidative injury is still unclear. The present study was designed to investigate the effects of DZ pretreatment against Aβ_1–42 induced oxidative damage and cytotoxicity. Through measures of DZ effects on Aβ_1–42 induced cellular damage, reactive oxygen species (ROS) and MDA generation and expressions of gp91phox and p47phox in cholinergic neurons, new insights into the neuroprotective mechanisms can be derived. Aβ_1–42 significantly decreased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide levels and increased ROS and MDA production; all effects were attenuated by pretreatment with DZ or diphenyleneiodonium chloride (a NOX2 inhibitor). Pretreatment with DZ also attenuated the upregulation of NOX2 subunits (gp91phox and p47phox) induced by Aβ_1–42. Since NOX2 is one of the main sources of free radicals, these results suggest that DZ can counteract Aβ_1–42 induced oxidative stress and associated cell death by reducing the level of ROS and MDA, in part, by alleviating NOX2 expression.