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WD40是转录因子大家族,具有调节花青素苷生物合成、植物生长发育及非生物胁迫响应等功能,LWD（LIGHT-REGULATED WD）基因是该家族中已知的生物钟调节因子,但目前有关植物LWD基因的报道较少,其功能还有待深入研究。为探究LWD基因对滇水金凤花色的影响,本研究以滇水金凤花器官为材料,采用RT-PCR等技术克隆得到2个滇水金凤LWD基因,分别命名为IuLWD1和IuLWD2,其cDNA全长分别为1041 bp和1032 bp,分别编码347个和344个氨基酸。基本理化性质分析显示,IuLWD1和IuLWD2的GC含量分别为46%和50%,相对分子量分别为38 838.47 kDa和39 029.65 kDa,理论等电点分别为4.71和4.70。IuLWD1和IuLWD2的不稳定指数分别为53.60和52.58,均属于不稳定蛋白;其总平均亲水指数分别为-0.388和-0.366,均为亲水性蛋白。结构域分析显示,IuLWD1和IuLWD2均含有6个典型的WD40-repeat保守结构域,属于WD40超家族。多序列比对发现,IuLWD1和IuLWD2氨基酸序列与牡丹、葡萄及杨梅等氨基酸序列相似度较高。系统发育分析表明,IuLWD1与葡萄和牡丹聚为一支,同源性达85%;IuLWD2与杨梅聚为一支,同源性达90%,然后共同聚类在一支,推测2个基因为旁系亲缘关系。qRT-PCR分析表明,IuLWD1和IuLWD2基因在4种不同花色滇水金凤及其4个不同发育阶段均有表达,均以深红色表达量最高,白色表达量最低,2个基因的表达量均与花色呈正相关,且IuLWD1基因的表达量高于IuLWD2基因的表达量,表明IuLWD1和IuLWD2基因均在滇水金凤花色素苷的生物合成中发挥了作用,且IuLWD1基因对滇水金凤花色形成的调控作用更强。该研究结果为进一步探究滇水金凤花色形成及变异机理、凤仙花花色改良及新品种培育奠定基础。 相似文献
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Dana R. Warren Clifford E. Kraft William S. Keeton Jared S. Nunery Gene E. Likens 《Forest Ecology and Management》2009
Wood is an important component of forested stream ecosystems, and stream restoration efforts often incorporate large wood. In most cases, however, stream restoration projects are implemented without information regarding the amount of wood that historically occurred or the natural rates of wood recruitment. This study uses a space-for-time analysis to quantify large wood loading to 28 streams in the northeastern US with a range of in-stream and riparian forest characteristics. We document the current volume and frequency of occurrence of large wood in streams with riparian forests varying in their stage of stand development as well as stream size and gradient. Linear models relating stream wood characteristics to stream geomorphic and forest characteristics were compared using Akaike's Information Criterion (AIC) model selection. The AIC analysis indicated that the volume and frequency of large wood and wood accumulations (wood jams) in streams was most closely associated with the age of the dominant canopy trees in the riparian forest (best models: log10(large wood volume (m3 100 m−1)) = (0.0036 × stand age) − 0.2281, p < 0.001, r2 = 0.80; and large wood frequency (number per 100 m) = (0.1326 × stand age) + 7.3952, p < 001, r2 = 0.63). Bankfull width was an important factor accounting for wood volume per unit area (m3 ha−1) but not the volume of wood per length of stream (100 m−1). The empirical models developed in this study were unsuccessful in predicting wood loading in other regions, most likely due to difference in forest characteristics and the legacy of forest disturbance. However, these models may be applicable in other streams in the northeastern US or in streams with comparable riparian forests, underlying geology, and disturbance regimes—factors that could alter long-term wood loading dynamics. Our results highlight the importance of understanding region-specific processes when planning stream restoration and stream management projects. 相似文献
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叶片湿润时间（LWD）是植物病害模型的重要输入变量之一，它与许多叶部病原菌的侵染有关，影响病原侵染和发育速率。为了准确地预测日光温室黄瓜病害的发生时间和方位，本研究于2019年3月和9月在北京两个不同类型日光温室内按照棋盘格法设置了9个采样点部署温湿光传感器和目测叶片湿润时间，每隔1 h采集一次温度、湿度、辐射和叶片湿润数据进行定量估算分析。分析结果表明：BP神经网络模型在两个温室的试验条件下获得了相似的准确度（ACC为0.90和0.92），比相对湿度经验模型估算叶片湿润时间的准确度（ACC为0.82和0.84）更高，平均绝对误差MAE分别为1.81和1.61 h，均方根误差RSME分别为2.10和1.87，决定系数R2分别为0.87和0.85；在晴天和多云天气条件下，叶片湿润时间的空间分布总体规律是南部＞中部＞北部，南面是叶片湿润平均时间（12.17 h/d）最长的区域；由东向西方向上，叶片湿润时间的空间分布总体规律是东部＞西部＞中部，中部是叶片湿润平均时间（4.83 h/d）最短的区域；雨天的叶片湿润平均时间比晴天和多云长，春季和秋季分别为17.15和17.41 h/d。这些变化和差异对温室黄瓜种群水平方向的叶片湿润时间分布具有重要影响，与大多数高湿性黄瓜病害的发生规律密切相关。本研究为预测温室黄瓜病害分布提供了有价值的参考，对控制病害流行和减少农药使用具有重要意义，提出的区域化分析温室内叶片湿润时间的方法，可以为模拟日光温室叶片湿润时间的空间分布提供参考。 相似文献
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