乙烯和水杨酸信号转导在拟南芥对聚乙二醇胁迫应答中的相互作用

Interaction between ethylene-and salicylic acid-signaling in Arabidopsis response to polyethylene glycol stress

前期研究显示,乙烯缺失或信号转导阻断促进植物对干旱胁迫的耐受性。发现拟南芥乙烯信号转导阻断突变体对聚乙二醇模拟的干旱胁迫耐受性与水杨酸信号转导相关。在6%及以上浓度的聚乙二醇胁迫下,拟南芥乙烯不敏感突变体ein2-1植株表现出较野生型植株更强的耐受性,但乙烯和水杨酸信号转导阻断双突变体ein2-1/npr1-1植株表现出较野生型植株更加敏感的特性。在聚乙二醇胁迫下,与野生型植株相比,ein2-1植株的相对含水量、光合作用相关参数、脯氨酸含量以及抗氧化酶活性更高,而过氧化氢含量和脂质过氧化水平更低。然而,上述参数在ein2-1/npr1-1植株中的表现较野生型植株更差。这些数据表明,乙烯不敏感突变介导的聚乙二醇耐受性需要水杨酸信号转导递体NPR1的生物学作用。

Early researches have demonstrated that ethylene（ET）deficiency or signaling insensitivity improves plant tolerance to drought stress.Here,we report that ET-mediated plant response to polyethylene glycol（PEG）-simulated drought stress could be connected to salicylic acid（SA）signaling.Under exposure to 6%（w/v）and higher concentrations of PEG,Arabidopsis ein2-1plants（ET insensitivity）exhibited a significant tolerance,whereas the ein2-1/npr1-1plants（double mutant with both ET-and SA-signaling insensitivity）suffered a severe damage,as compared with wild-type（WT）plants.Under the stress conditions,ein2-1plants had a higher level in relative water content, photosynthesis-related performance, proline content, and antioxidative capacity,but a lower level in H2O2 production and lipid peroxidation.However,these not only were reversed,but even worse in ein2-1/npr1-1plants than in WT plants.This suggested that the NPR1 functions were required for ein2-1-mediated Arabidopsis tolerance to drought stress.