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Li NJ  Zeng GM  Huang DL  Hu S  Feng CL  Zhao MH  Lai C  Huang C  Wei Z  Xie GX 《Bioresource technology》2011,102(17):8137-8142
The production of oxalate at different initial Pb2+ concentrations during solid-state fermentation of straw with Phanerochaete chrysosporium was investigated. It was found that the maximal peak value of oxalate concentration (22.84 mM) was detected at the initial Pb2+ concentration of 200 mg kg−1 dry straw, while the minimum (15.89 mM) at the concentration of 600 mg Pb2+ kg−1 dry straw, and at moderate concentration of Pb2+ the capability of oxalic acid secretion was enhanced. In addition, it was also found that more oxalic acid accumulation went together with better Pb2+ passivation effect and higher manganese peroxidase (MnP) activity. The present findings will improve the understandings of the interactions of heavy metals with white-rot fungi and the role of oxalate in lignin degradation system, which could provide useful references for more efficient treatment of Pb-contaminated lignocellulosic waste.  相似文献   
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[目的]研究中度嗜盐菌Martelella sp.AD-3在降解菲过程中水杨酸-5-羟化酶的活性与菲降解效率的关系及其酶学性质.[方法]通过HPLC分析菲的降解效率和AD-3菌粗酶液催化水杨酸的产物,根据NADH在340 nm处的吸光度变化计算水杨酸-5-羟化酶的活性.[结果]水杨酸-5-羟化酶是一种诱导酶,在AD-3菌的对数生长期和稳定初期时活性较高,酶活力大小与该菌对菲的降解速率基本一致.在菲浓度为200 mg/L、生长盐度为3%、pH为9.0的培养条件下,AD-3菌株表达的水杨酸-5-羟化酶的活力最高,为132.8 nmol/(min·mg).水杨酸-5-羟化酶催化水杨酸降解时的最适温度、pH和盐度分别为30℃、7.5和3%,酶的最大反应速率为200 nmol/(min· mg)、米氏常数Km为8.7μmol/L.[结论]AD-3菌在降解菲的过程中表达水杨酸-5-羟化酶,该酶的活性与菲降解速率具有相关性.  相似文献   
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The objective of this study was to explore the potential role of G-protein-coupled receptor kinase 2 (GRK2) in the progression of cannabinoid 2 receptor (CB2) agonist-induced analgesic effects of bone cancer pain. Female Sprague–Dawley rats, weighing 160–180 g, were utilized to establish a model of bone cancer pain induced by intra-tibia inoculation of Walker 256 mammary gland carcinoma cells. JWH-015, a selective CB2 agonist, was injected intrathecally or intraperitoneally on postoperative day 10. Bone cancer-induced pain behaviors—mechanical allodynia and ambulatory pain—were assessed on postoperative days ?1 (baseline), 4, 7, and 10 and at post-treatment hours 2, 6, 24, 48, and 72. The expressions of spinal CB2 and GRK2 protein were detected by Western Blotting on postoperative days ?1 (baseline), 4, 7, and 10 and at post-treatment hours 6, 24, and 72. The procedure produced prolonged mechanical allodynia, ambulatory pain, and different changes in spinal CB2 and GRK2 expression levels. Intrathecal or intraperitoneal administration of JWH-015 alleviated the induced mechanical allodynia and ambulatory pain, and inhibited the downregulation of spinal GRK2 expression. These effects were in a time-dependent manner and reversed by pretreatment of CB2 selective antagonist AM630. The results affirmed CB2 receptor agonists might serve as new treatment targets for bone cancer pain. Moreover, spinal GRK2 was an important regulator of CB2 receptor agonist-analgesia pathway.  相似文献   
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Ruozhu Lin  Bei Cui  Wenxia Zhao 《Phyton》2019,88(3):285-293
The flowers of the hemiparasitic family Loranthaceae are always subtended by a rimmed structure known as the calyculus. The origin and identity of the calyculus have been disputed for more than a century. Various hypotheses have been proposed, for example, an outgrowth of the axis, a reduced calyx, and a bracteolar (prophyllar) origin, but controversies remain. To obtain a plausible explanation of the origin of the calyculus, we investigated the flowers of Loranthus tanakae using scanning electron microscopy and light microscopy to observe the entire developmental process of the floral parts. Our results show that bracts are not present in L. tanakae. The calyculus, which lacks serving vascular bundles, initiates as a semicircular primordium and then develops into a circular structure by an adnation at both sides. The flower primordium usually cleaves into six petals from its centre along a whorled pattern in two series with three petals each, before or after the calyculus closed. Isomerous stamen primordia probably follow the same initiation pattern as petals do. Several carpels of different sizes initiate simultaneously as a united primordium. We support the hypotheses that the calyculus is of bract or bracteole origin due to its independent initiation from the inflorescence rachis, its similar morphology and positioning as the bract or bracteole, and that having no developmental relationship with the petals. We suggest keeping the usage of the term “calyculus”. Loranthus flowers should be considered monochlamydeous with three whorls of floral parts, namely petal, androecium, and gynoecium.  相似文献   
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Transport of photoassimilates from leaf tissues (source regions) to the sink organs is essential for plant development. Here, we show that a phytohormone, the brassinosteroids (BRs) promotes pollen and seed development in rice by directly promoting expression of Carbon Starved Anther (CSA) which encodes a MYB domain protein. Over‐expression of the BR‐synthesis gene D11 or a BR‐signaling factor OsBZR1 results in higher sugar accumulation in developing anthers and seeds, as well as higher grain yield compared with control non‐transgenic plants. Conversely, knockdown of D11 or OsBZR1 expression causes defective pollen maturation and reduced seed size and weight, with less accumulation of starch in comparison with the control. Mechanically, OsBZR1 directly promotes CSA expression and CSA directly triggers expression of sugar partitioning and metabolic genes during pollen and seed development. These findings provide insight into how BRs enhance plant reproduction and grain yield in an important agricultural crop.  相似文献   
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