Wang Haiguang, Zhang Hongliang, Gao Fenghua, Li Junxia, Li Zichao
Key Lab of Crop Genomics and Genetic Improvement of Ministry of Agriculture, Crop Heterosis and Utilization of Ministry of Education and Beijing Key Lab of Crop Genetic Improvement, China Agricultural University, China.
Theor Appl Genet. 2007 Nov;115(8):1109-26. doi: 10.1007/s00122-007-0637-7. Epub 2007 Sep 11.
To elucidate the differences in the regulation of water stress tolerance between two genotypes of rice, upland-rice (UR, resistant to water stress) and lowland-rice (LR, susceptible to water stress), we constructed subtracted cDNA libraries from polyethyleneglycol (PEG)-treated and non-treated rice seedlings (IRAT109, an upland-rice variety) by suppression subtractive hybridization (SSH), from which about 2,000 recombinant colonies were picked and amplified. Then, a cDNA microarray containing these expressed sequence tags (ESTs) was used to analyze the gene expression profiles in UR and LR in response to PEG treatment. Microarray data revealed that the majority of genes expressed in UR and LR are almost identical and Student's t test showed that 13% of all the ESTs detected in leaves and 7% of that in roots expressed differentially in transcripts abundance between the two genotypes. After sequencing, it was found that 64 and 79 unique ESTs expressed at higher levels in UR and LR, respectively. Many of the ESTs that showed higher expression in UR upon PEG treatment represented genes for transcription factors, genes playing roles in detoxification or protection against oxidative stress, and genes that help in maintaining cell turgor. In contrast, some ESTs that showed higher expression in LR were genes functioning in the degradation of cellular components. Based on data from this study and previous reports, we suggest that overexpression of some genes that expressed at higher level in UR may improve water stress tolerance in LR and other plant species.
为了阐明两种水稻基因型，即旱稻（UR，耐旱）和水稻（LR，易受水分胁迫）在水分胁迫耐受性调控方面的差异，我们通过抑制性消减杂交（SSH）从聚乙二醇（PEG）处理和未处理的水稻幼苗（旱稻品种IRAT109）构建了消减cDNA文库，从中挑选并扩增了约2000个重组菌落。然后，使用包含这些表达序列标签（EST）的cDNA微阵列分析UR和LR中响应PEG处理的基因表达谱。微阵列数据显示，UR和LR中表达的大多数基因几乎相同，学生t检验表明，在叶片中检测到的所有EST中有13%以及在根中检测到的EST中有7%在两种基因型之间的转录本丰度上差异表达。测序后发现，分别有64个和79个独特的EST在UR和LR中高水平表达。许多在PEG处理后在UR中显示出更高表达的EST代表转录因子基因、在解毒或抵抗氧化应激中起作用的基因以及有助于维持细胞膨压的基因。相反，一些在LR中显示出更高表达的EST是在细胞成分降解中起作用的基因。基于本研究和先前报告的数据，我们建议在UR中高水平表达的一些基因的过表达可能会提高LR和其他植物物种的水分胁迫耐受性。
