Temperature-induced lipocalin is required for basal and acquired thermotolerance in Arabidopsis
Temperature-induced lipocalin is required for basal and acquired thermotolerance in Arabidopsis
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DOI：
10.1111/j.1365-3040.2009.01972.x
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发表时间：
2009-07-01
影响因子：
7.3
通讯作者：
Charng, Yee-Yung
中科院分区：
文献类型：
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作者：
Chi, Wen-Tzu;Fung, Raymondw. M.;Charng, Yee-Yung
植物温度诱导的脂质钙素（TILs）已被证明对热胁迫（HS）有反应，但这种反应的性质尚不清楚。在这项研究中，采用反向遗传方法来阐明拟南芥TIL1 （At5g58070）在耐热性中的作用。TIL1的T-DNA敲除系（TIL1 -1）在基础（BT）和获得性耐热性（AT）方面存在严重缺陷，可以通过引入野生型基因进行补充。然而，过表达TIL1并没有显著提高转基因植株的耐热性。TIL1与质膜外周相关。转录组学分析表明，TIL1 -1幼苗的热休克反应除了TIL1的表达不同外，与野生型植株基本相同。TIL1水平不影响热休克蛋白诱导的温度阈值。离子泄漏分析表明，野生型和til1-1型幼苗的膜稳定性无显著差异。这些结果表明TIL1不参与调节膜的流动性或稳定性。然而，突变植株也比野生型对过氧化叔丁基更敏感，过氧化叔丁基是一种诱导脂质过氧化的试剂。综上所述，这些数据表明TIL1是耐热性的重要组成部分，可能通过对抗严重HS诱导的脂质过氧化而起作用。
Plant temperature-induced lipocalins (TILs) have been shown to be responsive to heat stress (HS), but the nature of this response was unknown. In this study, a reverse genetic approach was taken to elucidate the role of Arabidopsis TIL1 (At5g58070) in thermotolerance. A T-DNA knock-out line of TIL1 (til1-1) showed severe defects in basal (BT) and acquired thermotolerance (AT), which could be complemented by introducing the wild-type gene. However, over-expression of TIL1 did not significantly enhance thermotolerance in transgenic plants. TIL1 is peripherally associated with plasma membrane. Transcriptomic analysis showed that the heat shock response in til1-1 seedlings was about the same as in the wild-type plants except the expression of TIL1. The level of TIL1 did not affect the temperature threshold for heat shock protein induction. Ion leakage analysis revealed no significant difference in membrane stability between the wild-type and til1-1 seedlings. These results suggest that TIL1 is not involved in regulating membrane fluidity or stability. Nevertheless, the mutant plants were also more sensitive than the wild type to tert-butyl hydroperoxide, a reagent that induces lipid peroxidation. Taken together, these data indicate that TIL1 is an essential component for thermotolerance and probably functions by acting against lipid peroxidation induced by severe HS.