Jia Jinping, Fu Junjie, Zheng Jun, Zhou Xin, Huai Junling, Wang Jianhua, Wang Meng, Zhang Ying, Chen Xiaoping, Zhang Jinpeng, Zhao Jinfeng, Su Zhen, Lv Yuping, Wang Guoying
State Key Laboratory of Agrobiotechnology and National Center for Maize Improvement, China Agricultural University, Beijing, China.
Plant J. 2006 Dec;48(5):710-27. doi: 10.1111/j.1365-313X.2006.02905.x. Epub 2006 Oct 31.
Full-length cDNAs are very important for genome annotation and functional analysis of genes. The number of full-length cDNAs from maize (Zea mays L.) remains limited. Here we report the construction of a full-length enriched cDNA library from osmotically stressed maize seedlings by using the modified CAP trapper method. From this library, 2073 full-length cDNAs were collected and further analyzed by sequencing from both the 5'- and 3'-ends. A total of 1728 (83.4%) sequences did not match known maize mRNA and full-length cDNA sequences in the GenBank database and represent new full-length genes. After alignment of the 2073 full-length cDNAs with 448 maize BAC sequences, it was found that 84 full-length cDNAs could be mapped to the BACs. Of these, 43 genes (51.2%) have been correctly annotated from the BAC clones, 37 genes (44.0%) have been annotated with a different exon-intron structure from our cDNA, and four genes (4.76%) had no annotations in the TIGR database. Expression analysis of 2073 full-length maize cDNAs using a cDNA macroarray led to the identification of 79 genes upregulated by stress treatments and 329 downregulated genes. Of the 79 stress-inducible genes, 30 genes contain ABRE, DRE, MYB, MYC core sequences or other abiotic-responsive cis-acting elements in their promoters. These results suggest that these cis-acting elements and the corresponding transcription factors take part in plant responses to osmotic stress either cooperatively or independently. Additionally, the data suggest that an ethylene signaling pathway may be involved in the maize response to drought stress.
全长cDNA对于基因的基因组注释和功能分析非常重要。来自玉米（Zea mays L.）的全长cDNA数量仍然有限。在此，我们报道了利用改良的CAP捕获法构建来自渗透胁迫玉米幼苗的全长富集cDNA文库。从该文库中收集了2073个全长cDNA，并通过5'端和3'端测序进行进一步分析。共有1728个（83.4%）序列与GenBank数据库中已知的玉米mRNA和全长cDNA序列不匹配，代表新的全长基因。将2073个全长cDNA与448个玉米BAC序列进行比对后，发现有84个全长cDNA可以定位到BAC上。其中，43个基因（51.2%）已从BAC克隆中得到正确注释，37个基因（44.0%）的外显子-内含子结构与我们的cDNA注释不同，4个基因（4.76%）在TIGR数据库中没有注释。利用cDNA宏阵列对2073个玉米全长cDNA进行表达分析，鉴定出79个受胁迫处理上调的基因和329个下调的基因。在79个胁迫诱导基因中，30个基因的启动子中含有ABRE、DRE、MYB、MYC核心序列或其他非生物响应顺式作用元件。这些结果表明，这些顺式作用元件和相应的转录因子协同或独立地参与植物对渗透胁迫的响应。此外，数据表明乙烯信号通路可能参与玉米对干旱胁迫的响应。
