SAUR(SMALL AUXIN UP RNA)基因家族是促进下胚轴伸长的重要下游基因,然而在高温诱导的下胚轴伸长中SAURs受调控的分子机制尚有很多不明之处。热形态建成被定义为高等植物在最适温度和逆境高温之间的温和高温范围内发生的一系列形态变化...SAUR(SMALL AUXIN UP RNA)基因家族是促进下胚轴伸长的重要下游基因,然而在高温诱导的下胚轴伸长中SAURs受调控的分子机制尚有很多不明之处。热形态建成被定义为高等植物在最适温度和逆境高温之间的温和高温范围内发生的一系列形态变化。其中,高温诱导的下胚轴伸长是研究最为透彻的一个。该研究以拟南芥Col野生型、hy5突变体、35 S::HY5-HA/Col过表达植物和烟草为材料,采用抑制剂NPA处理实验、定量RT-PCR、染色质免疫共沉淀和双荧光素酶报告基因检测方法探索了高温调控SAUR1/2/3/4的分子机制。结果表明:(1)热形态建成信号转导通路中生长素处于HY5(ELONGATED HYPOCOTYL 5)的下游。(2)在20℃和29℃中,HY5抑制了SAUR1/2/3/4的转录。(3)在常温和高温中,HY5与SAUR1/2/3/4的启动子区染色质含有E-box的部分结合且这些结合被高温所抑制。(4)HY5对SAUR1/2/3/4的调控依然需要生长素的参与。综上认为,高温通过影响HY5与SAUR1/2/3/4启动子染色质的结合强度来调控这4个基因的转录,并且此调控过程需要生长素。该研究结果为高温调控下胚轴伸长下游基因的分子机制提供了新的见解。展开更多
With the globalization of the economy,maritime trade has surged,posing challenges in the supervision of marine vessel activities.An automatic identification system(AIS)is an effective means of shipping traffic service...With the globalization of the economy,maritime trade has surged,posing challenges in the supervision of marine vessel activities.An automatic identification system(AIS)is an effective means of shipping traffic service,but many uncertainties exist regarding its data quality.In this study,the AIS data from Haiyang(HY)series of satellites were used to assess the data quality,analyze the global ship trajectory distribution and update frequencies from 2019 to 2023.Through the analysis of maritime mobile service identity numbers,we identified 340185 unique vessels,80.1%of which adhered to the International Telecommunication Union standards.Approximately 49.7%of ships exhibit significant data gaps,and 1.1%show inconsistencies in their AIS data sources.In the central Pacific Ocean at low latitudes and along the coast of South America(30°-60°S),a heightened incidence of abnormal trajectories of ships has been consistently observed,particularly in areas associated with fishing activities.According to the spatial distribution of ship trajectories,AIS data exhibit numerous deficiencies,particularly in high-traffic regions such as the East China Sea and South China Sea.In contrast,ship trajectories in the polar regions,characterized by high latitudes,are relatively comprehensive.With the increased number of HY satellites equipped with AIS receivers,the quantity of trajectory points displays a growing trend,leading to increasingly complete trajectories.This trend highlights the significant potential of using AIS data acquired from HY satellites to increase the accuracy of vessel tracking.展开更多
为了明确除草活性菌株HY-021对藜(Chenopodium album L.)的侵染作用机理,利用电镜扫描技术观察该菌株接种藜后对藜叶片的侵染过程,并使用生理指标测定法对接种后藜植株体内活性物质含量变化进行了测定。结果表明,HY-021菌株的菌丝通过...为了明确除草活性菌株HY-021对藜(Chenopodium album L.)的侵染作用机理,利用电镜扫描技术观察该菌株接种藜后对藜叶片的侵染过程,并使用生理指标测定法对接种后藜植株体内活性物质含量变化进行了测定。结果表明,HY-021菌株的菌丝通过气孔侵入叶片组织,并寄生繁殖产孢,逐渐破坏组织,同时叶片表面开始失绿并伴随着病斑的形成,最终导致植株不能进行光合作用而死亡。HY-021菌株接种于藜植株后体内MDA含量逐渐升高,SOD、CAT、POD的活性呈现出先上升后下降的趋势。表明该菌株对植株生理防御机制中的酶有多方面的影响,接种后引起植物广泛的代谢变化。可溶性蛋白质含量总体上高于对照,表明受到菌株侵染后,可溶性蛋白质含量增加,植物的抵御能力增强。展开更多
海冰是海洋环境监测的重点对象,光学遥感能为海冰的精细化监测提供技术支持,实现海冰的动态监测与量化估算。中国海洋水色业务卫星星座——海洋一号C/D卫星(Haiyang-1C/D,以下简称HY-1C/D),搭载有适用于海冰监测的海岸带成像仪CZI (Coas...海冰是海洋环境监测的重点对象,光学遥感能为海冰的精细化监测提供技术支持,实现海冰的动态监测与量化估算。中国海洋水色业务卫星星座——海洋一号C/D卫星(Haiyang-1C/D,以下简称HY-1C/D),搭载有适用于海冰监测的海岸带成像仪CZI (Coastal Zone Imager)和水色水温扫描仪COCTS (Chinese Ocean Color and Temperature Scanner),具备开展海冰业务化监测应用的能力。本研究以2021年12月—2022年3月中国渤海辽东湾海冰为研究区,收集冰期内的HY-1C/D卫星影像数据,开展海冰识别与估算研究,评估CZI与COCTS数据对海冰的识别效能,分析海冰、海水、云等典型目标在光学(可见光—近红外)和热红外波段的影像特征;此外,针对光学遥感影像中海冰识别易受到云干扰问题,根据其在以上波段的遥感响应机理和图像特征差异,提出一种适用于HY-1C/D卫星在海冰分布区域的云掩膜方法,并对海冰进行精确提取;在识别基础上,进一步评估HY-1C/D卫星数据对于海冰密集度这一关键物理参数的光学遥感估算效能。结果表明:引入热红外波段,利用海冰和云的亮温差异对云进行掩膜,使得利用全局阈值提取海冰像元成为可能;通过对CZI、COCTS影像中海冰的高精度提取,进一步实现海冰密集度的估算,有效反映了像元中海冰和海水的混合程度,从而达到海冰海水像元解混的效果,提高海冰覆盖面积的估算精度。综上,本研究方法针对HY-1C/D卫星影像数据中的海冰识别提取具有较高的精度和抗干扰能力,可为国产海洋光学卫星的海冰监测业务化应用提供方法参考。展开更多
基金The National Key R&D Program of China under contract Nos 2021YFC2803305 and 2024YFC2816301the Fundamental Research Funds for the Central Universities of China under contract No.2042022dx0001.
文摘With the globalization of the economy,maritime trade has surged,posing challenges in the supervision of marine vessel activities.An automatic identification system(AIS)is an effective means of shipping traffic service,but many uncertainties exist regarding its data quality.In this study,the AIS data from Haiyang(HY)series of satellites were used to assess the data quality,analyze the global ship trajectory distribution and update frequencies from 2019 to 2023.Through the analysis of maritime mobile service identity numbers,we identified 340185 unique vessels,80.1%of which adhered to the International Telecommunication Union standards.Approximately 49.7%of ships exhibit significant data gaps,and 1.1%show inconsistencies in their AIS data sources.In the central Pacific Ocean at low latitudes and along the coast of South America(30°-60°S),a heightened incidence of abnormal trajectories of ships has been consistently observed,particularly in areas associated with fishing activities.According to the spatial distribution of ship trajectories,AIS data exhibit numerous deficiencies,particularly in high-traffic regions such as the East China Sea and South China Sea.In contrast,ship trajectories in the polar regions,characterized by high latitudes,are relatively comprehensive.With the increased number of HY satellites equipped with AIS receivers,the quantity of trajectory points displays a growing trend,leading to increasingly complete trajectories.This trend highlights the significant potential of using AIS data acquired from HY satellites to increase the accuracy of vessel tracking.
文摘为了明确除草活性菌株HY-021对藜(Chenopodium album L.)的侵染作用机理,利用电镜扫描技术观察该菌株接种藜后对藜叶片的侵染过程,并使用生理指标测定法对接种后藜植株体内活性物质含量变化进行了测定。结果表明,HY-021菌株的菌丝通过气孔侵入叶片组织,并寄生繁殖产孢,逐渐破坏组织,同时叶片表面开始失绿并伴随着病斑的形成,最终导致植株不能进行光合作用而死亡。HY-021菌株接种于藜植株后体内MDA含量逐渐升高,SOD、CAT、POD的活性呈现出先上升后下降的趋势。表明该菌株对植株生理防御机制中的酶有多方面的影响,接种后引起植物广泛的代谢变化。可溶性蛋白质含量总体上高于对照,表明受到菌株侵染后,可溶性蛋白质含量增加,植物的抵御能力增强。
文摘海冰是海洋环境监测的重点对象,光学遥感能为海冰的精细化监测提供技术支持,实现海冰的动态监测与量化估算。中国海洋水色业务卫星星座——海洋一号C/D卫星(Haiyang-1C/D,以下简称HY-1C/D),搭载有适用于海冰监测的海岸带成像仪CZI (Coastal Zone Imager)和水色水温扫描仪COCTS (Chinese Ocean Color and Temperature Scanner),具备开展海冰业务化监测应用的能力。本研究以2021年12月—2022年3月中国渤海辽东湾海冰为研究区,收集冰期内的HY-1C/D卫星影像数据,开展海冰识别与估算研究,评估CZI与COCTS数据对海冰的识别效能,分析海冰、海水、云等典型目标在光学(可见光—近红外)和热红外波段的影像特征;此外,针对光学遥感影像中海冰识别易受到云干扰问题,根据其在以上波段的遥感响应机理和图像特征差异,提出一种适用于HY-1C/D卫星在海冰分布区域的云掩膜方法,并对海冰进行精确提取;在识别基础上,进一步评估HY-1C/D卫星数据对于海冰密集度这一关键物理参数的光学遥感估算效能。结果表明:引入热红外波段,利用海冰和云的亮温差异对云进行掩膜,使得利用全局阈值提取海冰像元成为可能;通过对CZI、COCTS影像中海冰的高精度提取,进一步实现海冰密集度的估算,有效反映了像元中海冰和海水的混合程度,从而达到海冰海水像元解混的效果,提高海冰覆盖面积的估算精度。综上,本研究方法针对HY-1C/D卫星影像数据中的海冰识别提取具有较高的精度和抗干扰能力,可为国产海洋光学卫星的海冰监测业务化应用提供方法参考。
