香榧籽油对高脂膳食SD大鼠脂质代谢的影响及机理

为推进对香榧籽油生物功效的认知,以高脂膳食大鼠模型评估香榧籽油的降脂、抗氧化功效及其作用机理。将40只SD大鼠随机分为正常对照组（NF组）、2%香榧籽油正常组（NFO组）、高脂对照组（HF组）、2%香榧籽油高脂组（HFO组）。每周记录SD大鼠体重,分别在第4周和第7周检测血清中总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、血糖（Glu）、超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-Px）、总抗氧化能力（T-AOC）、C反应蛋白（CRP）、白介素6（IL-6）、白介素4（IL-4）水平。在第7周处死大鼠,解剖取肝脏、十二指肠、脂肪组织,采用油红O、苏木精-伊红（HE）染色观察组织形态,并采用qRT-PCR检测肝脏脂质代谢相关基因的表达。结果表明：实验第4周,与NF组相比,香榧籽油能极显著降低SD大鼠体重（P<0.01）,整个实验周期内HF、HFO组大鼠体重无显著差异;与NF组相比,NFO组大鼠血清TG、Glu、MDA水平显著下降（P<0.05）,HDL-C水平显著提高（P<0.05）;与HF组相比,香榧籽油能显著降低大鼠血清TC、LDL-C和Glu水平（P<0.05）,显著提高SOD、GSH-Px的活性和T-AOC（P<0.01,P<0.05）。实验第7周,与NF组相比,NFO组大鼠血清LDL-C水平极显著上升（P<0.01）,TC、MDA水平显著下降（P<005）;与HF组相比,香榧籽油能显著升高大鼠血清TG、LDL-C、MDA、CRP、IL-4水平（P<0.05,P<001）;长期食用香榧籽油,大鼠肝脏、十二指肠组织中偶有炎性细胞浸润,脂肪组织细胞形态大小不均。NFO组大鼠肝脏AMPKα、SREBP-1c基因表达水平极显著高于NF组（P<0.01）,HFO组大鼠肝脏FAS、ACC、AMPKα基因表达水平极显著低于HF组（P<0.01）。香榧籽油可能通过调节AMPKα/SREBP-1c信号通路实现调节大鼠血脂、提高抗氧化水平的生物功效。     

Estimation of gross primary production in Moso bamboo forest based on light-use efficiency derived from MODIS reflectance data

Assessing the contribution of Moso bamboo (Phyllostachys pubescens) forest to forest ecosystem carbon storage requires accurate estimation of gross primary production (GPP). Based on measurements of light-use efficiency (LUE), defined as the ratio of measured GPP to photosynthetically active radiation (PAR), from the eddy covariance flux tower, the linear regression model and partial least squares regression model were used for estimation of LUE using the Moderate-Resolution Imaging Spectroradiometer (MODIS) reflectance data. GPP estimates were then calculated by the product of LUE estimates and PAR (named the LUE-PAR model), which was compared with GPP from the GPP algorithm designed for the MODIS sensor aboard the Aqua and Terra platforms (MOD17A2 model) and the EC-LUE model. The results revealed the PLS model performed better than the linear regression model in LUE estimation but had lager uncertainties in high and low LUE values. GPP estimates driven by a MODIS-based radiation product with high spatial resolution was more accurate than those driven by Modern-Era Retrospective Analysis for Research and Applications (MERRA) radiation product from the NASA’s Global Modelling and Assimilation Office data set. The LUE-PAR model had the highest accuracy than the other two LUE models. The GPP values derived from the EC-LUE model driven by photosynthetically active radiation (PAR) from MERRA and maximum LUE from the EC data were overestimated due to the overestimation in MERRA radiation product. The GPP values derived from the MOD17A2 model driven by PAR from the MERRA and maximum LUE from the biome properties look-up table were underestimated due to underestimation in the maximum LUE of Moso bamboo forest. This study implied that the LUE-PAR model driven by LUE estimates from the PLS model and PAR from MERRA is a superior approach in improving GPP simulations, and PAR products with high spatial resolution and accurate species-specific maximum LUE are necessary for the LUE models in estimating GPP at regional scale.     

Jasmonate Signaling Pathway Modulates Plant Defense,Growth, and Their Trade-Offs

Lipid-derived jasmonates (JAs) play a crucial role in a variety of plant development and defense mechanisms. In recent years, significant progress has been made toward understanding the JA signaling pathway. In this review, we discuss JA biosynthesis, as well as its core signaling pathway, termination mechanisms, and the evolutionary origin of JA signaling. JA regulates not only plant regeneration, reproductive growth, and vegetative growth but also the responses of plants to stresses, including pathogen as well as virus infection, herbivore attack, and abiotic stresses. We also focus on the JA signaling pathway, considering its crosstalk with the gibberellin (GA), auxin, and phytochrome signaling pathways for mediation of the trade-offs between growth and defense. In summary, JA signals regulate multiple outputs of plant defense and growth and act to balance growth and defense in order to adapt to complex environments.     

基于MSP430F149的低功耗测树仪

为了解决目前国内树木的测量工具都依靠人工手动测量,且无法对树木的直径进行长期连续观测和自动记录的问题,设计了一种以MSP430F149芯片为核心的低功耗测树仪.对整个系统的软硬件实现进行了详细阐述,同时对系统功耗进行了估算及测试.该测树仪采用2节1.5 V电池供电,能够连续记录直径生长量,并提供了方便地数据采集接口,只要插入SD卡便可自动读取数据.研究结果表明,该测树仪具有结构简单、操作方便、数据自动记录与自动存储、低功耗、低成本等优点,具有较强的实用性.