Wake structures and vortex induced vibration （VIV） of a spring-supported wide-D-section cylinder were experimentally investigated using an X-wire, a novel phase-locked particle image velocimetry （PIV）, and an acce...Wake structures and vortex induced vibration （VIV） of a spring-supported wide-D-section cylinder were experimentally investigated using an X-wire, a novel phase-locked particle image velocimetry （PIV）, and an acceleration sensor at a low speed wind tunnel. Compared with the fixed case, the 2P （two pair） vortex mode as defined by Govardhan and Williamson （2000） rather than S （single vortex） mode exists in the wake. The velocity deficit behind the cylinder is much larger than that of fixed case. The mean drag coefficient increases from 1.42 for the fixed case to 1.64 for the vibrating case. The Reynolds stress presents even distribution and small with increased distance of X/D = -2 to X/D = -10. The power spectra density based on accelerator and hot wire data presents a highlight identical. It shows that after a strong interaction the cylinder vibration and the vortex shedding come to a stable state. The vortex sheddin~ is totally locked on and controlled by the cylinder vihratinn.展开更多
Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanism...Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanisms underlying these two traits remains unknown. In the present study, a cold-tolerant rice cultivar, Lijiangxintuanheigu, and a cold-sensitive cultivar, Sanhuangzhan-2, were subjected to low-temperature treatments and physiolog-ical and genome-wide gene expression analyses were conducted. Leaf rolling occurred at temperatures lower than 11℃, whereas discoloration appeared at moderately low temperatures such as 13℃. Chlorophyll contents in both cultivars were significantly decreased at 13℃, but not altered at 11℃. In contrast, the relative water content and relative electrolyte leakage of both cultivars decreased significantly at 11℃, but did not change at 13℃. Expression of genes associated with calcium signaling and abscisic acid (ABA) degradation was significantly altered at 11℃ in comparison with 25℃ and 13℃. Numerous genes in the DREB, MYB, bZIP, NAC, Zinc finger, bHLH, and WRKY gene families were differentially expressed. Many aquaporin genes and the key genes in trehalose and starch synthesis were down regulated at 11℃ in comparison with 25℃ and 13℃. These results suggest that the two chilling injury symptoms are temperature-specific and are controlled by different mechanisms. Cold-induced leaf rolling is associated with calcium and ABA signaling pathways and is regulated by multiple transcriptional regulators. The suppression of aquaporin genes and reduced accumulation of soluble sugars under cold stress results in a reduction in cellular water potential and consequently leaf rolling.展开更多
【目的】从芝麻全基因组中分离鉴定水通道蛋白AQP(aquaporin)家族基因,并进行系统进化关系、连锁群定位、基因结构、跨膜结构域和亚细胞定位预测、保守性氨基酸残基以及青枯雷尔氏菌诱导表达分析,为芝麻AQP的功能研究与利用奠定基础。...【目的】从芝麻全基因组中分离鉴定水通道蛋白AQP(aquaporin)家族基因,并进行系统进化关系、连锁群定位、基因结构、跨膜结构域和亚细胞定位预测、保守性氨基酸残基以及青枯雷尔氏菌诱导表达分析,为芝麻AQP的功能研究与利用奠定基础。【方法】通过生物信息学手段,结合芝麻基因组注释信息,鉴定芝麻AQP家族成员序列信息,并用InterPro逐一进行验证。利用ClustalW2对芝麻、拟南芥和水稻的AQP以及马铃薯的XIPs进行多序列比对,用MEGA6.0构建进化树。通过MapInspect和Gene Structure Display Server 2.0进行连锁群定位和基因结构分析。采用ProtParam、WoLF PSORT和TMHMM Server v.2.0在线工具预测芝麻水通道蛋白的分子质量和等电点、亚细胞定位及跨膜结构域。通过芝麻、拟南芥和水稻AQP及马铃薯XIPs的蛋白多序列比对结果推测NPA基序、ar/R滤器及P1—P5的氨基酸残基。利用前期研究获得的转录组测序结果进行青枯雷尔氏菌诱导表达分析,并通过qRT-PCR技术对差异表达较为明显的12个芝麻AQP进行验证。【结果】系统分析鉴定了36个芝麻AQP家族基因,根据多序列比对及系统进化分析将其分为5个亚家族:13个质膜内在蛋白(PIP)、12个液胞膜内在蛋白(TIP)、8个类NOD26膜内在蛋白(NIP)、2个膜内在小分子碱性蛋白(SIP)和1个未知内在蛋白(XIP),其中有34个基因定位在12个连锁群上。同一亚家族成员在基因结构、蛋白序列、亚细胞定位预测及保守性氨基酸残基等方面都较为相似。青枯雷尔氏菌诱导表达分析显示,NIPs、SIPs和XIPs表达无明显变化,部分PIPs和TIPs能够响应青枯菌诱导。SiPIP1;2、SiPIP1;3、SiPIP2;3和SiPIP2;4受青枯菌诱导后表达上调,SiPIP1;3和SiPIP2;3为持续上调,而SiPIP1;2和SiPIP2;4的表达先下调后上调;与之相反,表达下调较为显著的有SiPIP1;4、SiPIP2;1、SiPIP2;6、SiTIP1;1、SiTIP1;3、SiTIP2;1及SiTIP2;2。上述差异表达基因的qRT-PCR验证结果与转录组测序结果一致。【结论】通过全基因组分析,在芝麻中鉴定出36个AQP家族基因,分为5个亚家族,分布于12个连锁群上,大部分基因具有1—4个内含子(除SiNIP1;2有7个内含子外)。根据ar/R滤器和P1—P5氨基酸残基组成类型,预测不同亚家族AQP可能识别的底物。青枯菌诱导表达分析表明,部分PIPs和TIPs成员的表达发生了显著变化。展开更多
基金supported by the National Natural Science Foundation of China(11472158)
文摘Wake structures and vortex induced vibration （VIV） of a spring-supported wide-D-section cylinder were experimentally investigated using an X-wire, a novel phase-locked particle image velocimetry （PIV）, and an acceleration sensor at a low speed wind tunnel. Compared with the fixed case, the 2P （two pair） vortex mode as defined by Govardhan and Williamson （2000） rather than S （single vortex） mode exists in the wake. The velocity deficit behind the cylinder is much larger than that of fixed case. The mean drag coefficient increases from 1.42 for the fixed case to 1.64 for the vibrating case. The Reynolds stress presents even distribution and small with increased distance of X/D = -2 to X/D = -10. The power spectra density based on accelerator and hot wire data presents a highlight identical. It shows that after a strong interaction the cylinder vibration and the vortex shedding come to a stable state. The vortex sheddin~ is totally locked on and controlled by the cylinder vihratinn.
基金supported in part by the Ph.D. Start-up Fund of Natural Science Foundation of Guangdong Province, China (2015A030310419)the Guangdong Scientific and Technological Plan (2015B020231002, 2017A070702006, 2017A020208022)+3 种基金the Guangzhou Scientific and Technological Plan (201804020078)the Guangdong-Hong Kong joint project (2017A050506035)the Development Project of Guangdong Provincial Key Lab (2017B030314173)the Special Fund of Central Government Guided Local Scientific Development
文摘Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanisms underlying these two traits remains unknown. In the present study, a cold-tolerant rice cultivar, Lijiangxintuanheigu, and a cold-sensitive cultivar, Sanhuangzhan-2, were subjected to low-temperature treatments and physiolog-ical and genome-wide gene expression analyses were conducted. Leaf rolling occurred at temperatures lower than 11℃, whereas discoloration appeared at moderately low temperatures such as 13℃. Chlorophyll contents in both cultivars were significantly decreased at 13℃, but not altered at 11℃. In contrast, the relative water content and relative electrolyte leakage of both cultivars decreased significantly at 11℃, but did not change at 13℃. Expression of genes associated with calcium signaling and abscisic acid (ABA) degradation was significantly altered at 11℃ in comparison with 25℃ and 13℃. Numerous genes in the DREB, MYB, bZIP, NAC, Zinc finger, bHLH, and WRKY gene families were differentially expressed. Many aquaporin genes and the key genes in trehalose and starch synthesis were down regulated at 11℃ in comparison with 25℃ and 13℃. These results suggest that the two chilling injury symptoms are temperature-specific and are controlled by different mechanisms. Cold-induced leaf rolling is associated with calcium and ABA signaling pathways and is regulated by multiple transcriptional regulators. The suppression of aquaporin genes and reduced accumulation of soluble sugars under cold stress results in a reduction in cellular water potential and consequently leaf rolling.
文摘【目的】从芝麻全基因组中分离鉴定水通道蛋白AQP(aquaporin)家族基因,并进行系统进化关系、连锁群定位、基因结构、跨膜结构域和亚细胞定位预测、保守性氨基酸残基以及青枯雷尔氏菌诱导表达分析,为芝麻AQP的功能研究与利用奠定基础。【方法】通过生物信息学手段,结合芝麻基因组注释信息,鉴定芝麻AQP家族成员序列信息,并用InterPro逐一进行验证。利用ClustalW2对芝麻、拟南芥和水稻的AQP以及马铃薯的XIPs进行多序列比对,用MEGA6.0构建进化树。通过MapInspect和Gene Structure Display Server 2.0进行连锁群定位和基因结构分析。采用ProtParam、WoLF PSORT和TMHMM Server v.2.0在线工具预测芝麻水通道蛋白的分子质量和等电点、亚细胞定位及跨膜结构域。通过芝麻、拟南芥和水稻AQP及马铃薯XIPs的蛋白多序列比对结果推测NPA基序、ar/R滤器及P1—P5的氨基酸残基。利用前期研究获得的转录组测序结果进行青枯雷尔氏菌诱导表达分析,并通过qRT-PCR技术对差异表达较为明显的12个芝麻AQP进行验证。【结果】系统分析鉴定了36个芝麻AQP家族基因,根据多序列比对及系统进化分析将其分为5个亚家族:13个质膜内在蛋白(PIP)、12个液胞膜内在蛋白(TIP)、8个类NOD26膜内在蛋白(NIP)、2个膜内在小分子碱性蛋白(SIP)和1个未知内在蛋白(XIP),其中有34个基因定位在12个连锁群上。同一亚家族成员在基因结构、蛋白序列、亚细胞定位预测及保守性氨基酸残基等方面都较为相似。青枯雷尔氏菌诱导表达分析显示,NIPs、SIPs和XIPs表达无明显变化,部分PIPs和TIPs能够响应青枯菌诱导。SiPIP1;2、SiPIP1;3、SiPIP2;3和SiPIP2;4受青枯菌诱导后表达上调,SiPIP1;3和SiPIP2;3为持续上调,而SiPIP1;2和SiPIP2;4的表达先下调后上调;与之相反,表达下调较为显著的有SiPIP1;4、SiPIP2;1、SiPIP2;6、SiTIP1;1、SiTIP1;3、SiTIP2;1及SiTIP2;2。上述差异表达基因的qRT-PCR验证结果与转录组测序结果一致。【结论】通过全基因组分析,在芝麻中鉴定出36个AQP家族基因,分为5个亚家族,分布于12个连锁群上,大部分基因具有1—4个内含子(除SiNIP1;2有7个内含子外)。根据ar/R滤器和P1—P5氨基酸残基组成类型,预测不同亚家族AQP可能识别的底物。青枯菌诱导表达分析表明,部分PIPs和TIPs成员的表达发生了显著变化。
