[ATHK1 gene regulates signal transduction of osmotic stress in Arabidopsis thaliana].
[ATHK1 gene regulates signal transduction of osmotic stress in Arabidopsis thaliana].
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发表时间：
2004-10
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通讯作者：
G. Hao;Zhong-Yi Wu;Maohua Chen;M. Cao;G. Pelletier;Conglin Huang;Qing Yang
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作者：
G. Hao;Zhong-Yi Wu;Maohua Chen;M. Cao;G. Pelletier;Conglin Huang;Qing Yang
分析了拟南芥ATHK 1基因敲除突变体与野生型（WT）在生理和基因表达方面的差异。ATHK 1突变体离体叶片失水率明显高于WT。经30%PEG-6000处理后，野生型叶片细胞膜离子渗漏率比PEG处理前提高了50%，突变体叶片细胞膜离子渗漏率提高了80%。PEG处理48 h后ATHK 1突变体的萎蔫表型高于WT。这些结果表明ATHK 1突变体对渗透胁迫的敏感性高于WT和ATHK 1参与渗透胁迫适应。差异显示反转录PCR（DDRT-PCR）分析ATHK 1突变体与野生型之间基因表达的差异。9个差异cDNA片段参与胁迫适应，包括MAPKKK 18和丝氨酸/苏氨酸蛋白激酶基因。这些片段在WT中被PEG处理上调，但在ATHK 1突变体中没有。这些结果表明ATHK 1在渗透胁迫信号转导途径中位于MAPK的上游。ATHK 1可能作为植物呼吸传感器工作。
Differences in physiology and gene expression between ATHK1 knock-out mutant caused by T-DNA insertion and wild type (WT) of WS accession of Arabidopsis thaliana were analysed. Water loss ratio of detached leaf of ATHK1-mutant was obviously higher than that of WT. After being treated with 30% PEG-6000, ion leakage ratio of cell membrane in wild type leaves was 50% higher than that before PEG treatment, while in mutant leaves it increased 80%. The wilted phenotype of ATHK1-mutant after PEG treatment for 48 h was higher than that of WT. All these results showed that ATHK1-mutant was more sensitive to osmotic stress compared to WT and ATHK1 involved in osmotic stress adaptation. Differential-Display Reverse Transcription-PCR (DDRT-PCR) analysis was carried out to investigate the difference of gene expression between ATHK1-mutant and WT. Nine differential cDNA fragments involved in stress adaptation were identified, including the MAPKKK18 and serine/threonine protein kinase genes. These fragments were up-regulated by PEG treatment in WT, but not in ATHK1-mutant. These results indicate that ATHK1 plays an important role up-stream from MAPK in the osmotic stress signal transduction pathway. ATHK1 may be working as a plant osmosensor.