首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   360篇
  免费   121篇
  2019年   3篇
  2016年   5篇
  2015年   7篇
  2014年   13篇
  2013年   16篇
  2012年   5篇
  2011年   9篇
  2010年   12篇
  2009年   12篇
  2008年   12篇
  2007年   14篇
  2006年   13篇
  2005年   12篇
  2004年   16篇
  2003年   14篇
  2002年   20篇
  2001年   14篇
  2000年   14篇
  1999年   9篇
  1998年   5篇
  1997年   9篇
  1996年   5篇
  1995年   8篇
  1994年   10篇
  1993年   4篇
  1992年   19篇
  1991年   18篇
  1990年   17篇
  1989年   13篇
  1988年   15篇
  1987年   8篇
  1986年   12篇
  1985年   8篇
  1984年   14篇
  1983年   9篇
  1982年   3篇
  1980年   3篇
  1979年   13篇
  1977年   3篇
  1976年   3篇
  1974年   3篇
  1973年   3篇
  1972年   3篇
  1971年   4篇
  1970年   3篇
  1967年   3篇
  1966年   3篇
  1941年   2篇
  1932年   2篇
  1922年   2篇
排序方式: 共有481条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Summary A gene encoding acetolactate synthase was cloned from a chlorsulfuron-resistant mutant of Arabidopsis. The DNA sequence of the mutant gene differed from that of the wild type by a single base pair substitution. When introduced into tobacco by Ti plasmid-mediated transformation the gene conferred a high level of herbicide resistance. These results suggest that the cloned gene may confer agronomically useful levels of herbicide resistnace in other crop species, and that it may be useful as a selectable marker for plant transformation experiments.  相似文献   
9.
A starch deficient mutant of Arabidopsis thaliana (L.) Heynh. has been isolated in which leaf extracts contain only about 5% as much activity of ADPglucose pyrophosphorylase (EC 2.7.7.27) as the wild type. A single, nuclear mutation at a previously undescribed locus designated adg2 is responsible for the mutant phenotype. Although the mutant contained only 5% as much ADPglucose pyrophosphorylase activity as the wild type, it accumulated 40% as much starch when grown in a 12 hour photoperiod. The mutant also contained about 40% as much starch as the wild type when grown in continuous light, suggesting that the rate of synthesis regulates its steady state accumulation. Immunological analysis of leaf extracts using antibodies against the spinach 54 and 51 kilodalton (kD) ADPglucose pyrophosphorylase subunits indicated that the mutant is deficient in a cross-reactive 54 kD polypeptide and has only about 4% as much as the wild type of a cross-reactive 51 kD polypeptide. This result and genetic studies suggested that adg2 is a structural gene which codes for the 54 kD polypeptide, and provides the first functional evidence that the 54 kD polypeptide is a required component of the native ADPglucose pyrophosphorylase enzyme.  相似文献   
10.
Characterization of an HSP70 Cognate Gene Family in Arabidopsis   总被引:6,自引:4,他引:2       下载免费PDF全文
Analysis of the polypeptide composition of extracts from heat-shocked leaves of Arabidopsis indicated the presence of at least 12 HSP70-related polypeptides, most of which were constitutively expressed. In vitro translation of mRNA from heat-shocked and control leaves indicated that the amount of mRNA encoding four HSP70 polypeptides was increased strongly by heat-shock. Three Arabidopsis genes which exhibit homology to a Drosophila HSP70 gene were cloned. Two of the three genes are arranged in direct orientation approximately 1.5 kilobases apart. The third gene is not closely linked to the other two. Nucleotide sequence analysis of the 5′ regions of the two linked genes revealed that both contain a TATA box, the CAAT motif, and several short sequences which are homologous to the Drosophila heat-shock consensus sequence. The deduced partial amino acid sequence of the open reading frames were 79 and 72% homologous to the corresponding regions of the Drosophila HSP70-cognate and HSP70 sequences, respectively. As with the two maize HSP70 genes which have been characterized, and the Drosophila HSP70-cognate genes, the Arabidopsis genes contained a putative intron in the codon specifying amino acid 72. Analysis of mRNA levels with gene-specific oligonucleotide probes indicated that two of the genes were not expressed or were expressed at very low levels in leaves during normal growth or after heat-shock, whereas the other gene was constitutively expressed. By analogy with the results of similar studies of other organisms, it appears that the three cloned genes are members of a small family which are most closely related to the HSP70-cognate genes found in other species.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号