Thermotolerance through isoprene emission and the novel mechanism of decrease in leaf surface temperature in plants

研究了异戊二烯合成酶(ISPs)在拟南芥中表达的耐热性机制，转基因植株在60℃的温度下处理2.5h。我们系统地比较了野生型和ISPs表达的拟南芥中各种内源植物激素的含量，但发现存在显著差异。在分析中我们发现，在23℃培养一周的情况下，处理植株对剧烈和短期热激的耐受性似乎与处理植株的恢复率不同。结合最近一篇关于表达ISPS的烟草植物对臭氧胁迫耐性的报道，我们观察到的耐热性可能是由于异戊二烯耗尽了热激处理后质体中产生的活性氧物种，而异戊二烯实际上是大气中的OH自由基清除剂。

Mechanism of thermotolerance by expressing isoprene synthase(IspS) in Arabidopsis thaliana has been studied, in which transgenic plants were treated at 60℃for 2. 5 hr. We compared various endogenous plant hormone contents between wild type and IspS-expressing Arabidopsis systematically, but could find significant difference. During the analysis we found that the tolerance to drastic and short time heat shock seems to be different to recovery rate of treated plants on cultivation at 23℃for a week. Considering with a recent report on the tolerance of IspS-expressing tobacco plant to ozone stress, it is suggested that the thermotolerance we observed may be due to the depletion of reactive oxygen species raised after heat shock treatment in plastids by isoprene, which actually functions as OH radical scavenger in atomosphere.