目的探讨Ras相关结构域家族成员7(Ras-association domain family 7,RASSF7)在结直肠癌(colorectal cancer,CRC)组织中的表达及对CRC细胞系生物学特性的影响。方法应用免疫组化法检测RASSF7在80例CRC组织中的表达,并分析其与各临床病理...目的探讨Ras相关结构域家族成员7(Ras-association domain family 7,RASSF7)在结直肠癌(colorectal cancer,CRC)组织中的表达及对CRC细胞系生物学特性的影响。方法应用免疫组化法检测RASSF7在80例CRC组织中的表达,并分析其与各临床病理特征的关系;Western blot实验检测RASSF7在CRC细胞系中的表达,选出RASSF7高、低表达的CRC细胞株各一种,应用RASSF7过表达质粒和敲除质粒瞬时转染CRC细胞,MTT和Transwell实验分别检测RASSF7对CRC细胞增殖及侵袭的影响。结果免疫组化结果显示:CRC组织中RASSF7高表达50例,低表达30例,CRC组织中RASSF7表达明显高于癌旁正常组织,RASSF7高表达与患者年龄(P=0.238)、性别(P=0.065)及肿瘤分化程度(P=0.238)无关,而与TNM分期(P<0.001)及淋巴结转移(P=0.030)相关;RASSF7过表达可促进CRC细胞的增殖及侵袭能力(P<0.01),而敲除RASSF7则作用相反(P<0.01)。结论RASSF7在CRC中可能发挥促癌基因的作用,其高表达可显著促进CRC细胞的增殖及侵袭能力。展开更多
Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particu...Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particularly in alkaline soils. The plant growth, P uptake, and P availability in the rhizosphere of oat （Arena nuda L.） grown in hydroponics and in soil culture were investigated under supply with sole NH4^＋-N, sole NO3-N, or a combination. Sole NO^- -fed oat plants accumulated more biomass than sole NH4^＋ -fed ones. The highest biomass accumulation was observed when N was supplied with both NH^＋ -N and NO3^- -N. Growth of the plant root increased with the proportion of NO3^- in the cultural medium. Better root growth and higher root/shoot ratio were consistently observed in NO3^- fed plants. However, root vigor was the highest when N was supplied with NO3^- ＋NH4^＋. NH4^＋ supply reduced the rhizosphere pH but did not affect P uptake by plants grown in soils with CaHPO4 added as P source. No P deficiency was observed, and plant P concentrations were generally above 2 g kg^-1. P uptake was increased when N was supplied partly or solely as NO3^--N, similarly as biomass accumulation. The results suggested that oat was an NO3-preferring plant, and NO3^- -N was essential for plant growth and the maintenance of root absorption capacity. N supply with NH4^＋ -N did not improve P nutrition, which was most likely due to the absence of P deficiency.展开更多
China is one of the largest centers of genetic diversity of Oryza sativa L. and is the original centers of Oryza sativa L. subspecies japonica. Using a genetically representative core collection of 1 442 rice landrace...China is one of the largest centers of genetic diversity of Oryza sativa L. and is the original centers of Oryza sativa L. subspecies japonica. Using a genetically representative core collection of 1 442 rice landraces of japonica in China, the genetic structure, differentiation, and geographic diversity were analyzed. The model-based structure analysis on varieties within three ecotypes revealed 16 eco-geographical types, which are partially accorded with some of the ecological zones in China. The differentiation of eco-geographical types contributed to the local ecological adaption and physical isolation, and maybe could be used to develop the heterotic groups of japonica. To facilitate the identification of different ecotypes and eco-geographical types, we provided the SSR character alleles of each ecotype or geographical eco-group and a rapid discriminated method based on these character alleles. Lastly, investigation on genetic diversity, genetic differentiation indicated that southwest region of China, including south of Yunnan Province, northwest of Guangxi Zhuang Autonomous Region, and southwest of Guizhou Province, possessed the highest genetic diversity and all the necessary conditions as a center of genetic diversity and should be the center of genetic diversity of rice landraces of japonica in China.展开更多
基金Project supported by the National Natural Science Foundation Council of China (No.30660086)the Natural Science Foundation of Inner Mongolia of China (No.200607010302)+2 种基金Hong Kong Research Grants Council (No.2465/05M)Hong Kong University Grants Committee (No.AOE/B-07/99)Hong Kong Baptist University Matching Research Fund.
文摘Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particularly in alkaline soils. The plant growth, P uptake, and P availability in the rhizosphere of oat （Arena nuda L.） grown in hydroponics and in soil culture were investigated under supply with sole NH4^＋-N, sole NO3-N, or a combination. Sole NO^- -fed oat plants accumulated more biomass than sole NH4^＋ -fed ones. The highest biomass accumulation was observed when N was supplied with both NH^＋ -N and NO3^- -N. Growth of the plant root increased with the proportion of NO3^- in the cultural medium. Better root growth and higher root/shoot ratio were consistently observed in NO3^- fed plants. However, root vigor was the highest when N was supplied with NO3^- ＋NH4^＋. NH4^＋ supply reduced the rhizosphere pH but did not affect P uptake by plants grown in soils with CaHPO4 added as P source. No P deficiency was observed, and plant P concentrations were generally above 2 g kg^-1. P uptake was increased when N was supplied partly or solely as NO3^--N, similarly as biomass accumulation. The results suggested that oat was an NO3-preferring plant, and NO3^- -N was essential for plant growth and the maintenance of root absorption capacity. N supply with NH4^＋ -N did not improve P nutrition, which was most likely due to the absence of P deficiency.
基金supported by the National Basic Research Program of China (2010CB125904,2004CB117201)the National Natural Science Foundation of China(30871506)
文摘China is one of the largest centers of genetic diversity of Oryza sativa L. and is the original centers of Oryza sativa L. subspecies japonica. Using a genetically representative core collection of 1 442 rice landraces of japonica in China, the genetic structure, differentiation, and geographic diversity were analyzed. The model-based structure analysis on varieties within three ecotypes revealed 16 eco-geographical types, which are partially accorded with some of the ecological zones in China. The differentiation of eco-geographical types contributed to the local ecological adaption and physical isolation, and maybe could be used to develop the heterotic groups of japonica. To facilitate the identification of different ecotypes and eco-geographical types, we provided the SSR character alleles of each ecotype or geographical eco-group and a rapid discriminated method based on these character alleles. Lastly, investigation on genetic diversity, genetic differentiation indicated that southwest region of China, including south of Yunnan Province, northwest of Guangxi Zhuang Autonomous Region, and southwest of Guizhou Province, possessed the highest genetic diversity and all the necessary conditions as a center of genetic diversity and should be the center of genetic diversity of rice landraces of japonica in China.
