Expression of tobacco ethylene receptor NTHK1 alters plant responses to salt stress
Expression of tobacco ethylene receptor NTHK1 alters plant responses to salt stress
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DOI：
10.1111/j.1365-3040.2006.01501.x
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发表时间：
2006-07-01
影响因子：
7.3
通讯作者：
Chen, Shou-Yi
中科院分区：
文献类型：
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作者：
Cao, Wan-Hong;Liu, Jun;Chen, Shou-Yi
乙烯被认为是一种应激激素，参与许多应激反应。然而，乙烯受体在盐胁迫条件下的作用尚未得到研究。此前，我们从烟草中鉴定了乙烯受体基因NTHK1，并发现NTHK1是盐诱导的。在这里，我们报告了通过转基因方法进一步研究NTHK1在盐胁迫响应中的功能。我们发现NTHK1在盐胁迫条件下促进转基因烟草幼苗叶片生长，但影响转基因烟草幼苗的盐敏感性。盐胁迫处理后，Xanthi和nthk1转基因对照植株的Na+/K+比值存在差异。我们进一步发现，NTHK1在转基因植株中也具有盐诱导作用，NTHK1的高表达导致盐胁迫下ACC（1-氨基环丙烷-1-羧酸）氧化酶基因NtACO3和乙烯反应因子（ERF）基因NtERF1和NtERF4的早期诱导。然而，NTHK1抑制盐诱导的ACC合成酶基因NtACS1的表达。这些结果表明，NTHK1通过影响离子积累和相关基因表达来调控盐胁迫反应，因此对阐明胁迫信号转导过程中乙烯受体的功能具有重要意义。
Ethylene has been regarded as a stress hormone involved in many stress responses. However, ethylene receptors have not been studied for the roles they played under salt stress condition. Previously, we characterized an ethylene receptor gene NTHK1 from tobacco, and found that NTHK1 is salt-inducible. Here, we report a further investigation towards the function of NTHK1 in response to salt stress by using a transgenic approach. We found that NTHK1 promotes leaf growth in the transgenic tobacco seedlings but affects salt sensitivity in these transgenic seedlings under salt stress condition. Differential Na+/K+ ratio was observed in the control Xanthi and NTHK1-transgenic plants after salt stress treatment. We further found that the NTHK1 transgene is also salt-inducible in the transgenic plants, and the higher NTHK1 expression results in early inductions of the ACC (1-aminocyclopropane-1-carboxylic acid) oxidase gene NtACO3 and ethylene responsive factor (ERF) genes NtERF1 and NtERF4 under salt stress. However, NTHK1 suppresses the salt-inducible expression of the ACC synthase gene NtACS1. These results indicate that NTHK1 regulates salt stress responses by affecting ion accumulation and related gene expressions, and hence have significance in elucidation of ethylene receptor functions during stress signal transduction.