H2S作为植物个体间交流的气体信号分子

植物遭受到昆虫取食、创伤及非生物胁迫时,会向环境中释放多种挥发性物质,直接或间接地帮助受胁迫植株抵抗伤害。同时,这些挥发性物质向附近的健康植株传递信息,以应对可能到来的侵害。硫化氢(H2S)作为细胞内气体信号分子提高植物对多种胁迫的抗性已有报道,本论文对H2S是否作为植物个体间传递信息的信号分子进行了研究。结果表明:40%PEG8000处理可以使谷子、白菜、番茄和拟南芥Col-0植株所在环境空气中H2S含量升高;谷子和拟南芥Col-0植株经PEG8000处理后,可以使邻近的非胁迫植株叶片的H2S含量升高和H2S响应基因表达变化,并诱导非胁迫植株气孔关闭;而拟南芥内源H2S产生酶基因LCD和DES1双基因突变体lcd/des1经PEG8000处理,不能引起空气中和邻近植物的H2S含量升高,不能诱导邻近植株气孔关闭。本论文表明,H2S可以作为植物个体间的信息传递分子;即受胁迫植物通过向周围环境中释放H2S,向邻近植株提供胁迫预警信息,可能对种群的生存有重要意义。

H2S as A Gasotransmitter for Communication between Plant Individuals

Plant releases a variety of volatile substances into the environment when they suffered from insect feeding, wound or abiotic stress, to help plant combat the damage directly or indirectly. These volatile substances can also provide a precaution for the nearby plants to cope with the incoming threat. H₂S has been reported as an intracellular gasotransmitter which can increase the tolerance of plant to multiple stresses. We explored the possibility of H₂S to be a plant-to-plant signaling molecule in multiple plants. The H₂S concentrations in air increased when the foxtail millet, Chinese cabbage, tomato or Arabidopsis seedlings were treated with 40% PEG 8000. When the Arabidopsis or the foxtail millet was treated with PEG 8000, the H₂S content and the expression levels of the H₂S response genes in the neighboring non-stressed plants were increased, and the stomatal closure of these plant was also induced. However, when the lcd/des1 was treated with PEG 8000, not a similar phenomenon could be observed in the neighboring plants of this mutant. Therefore, H₂S not only functions as an intracellular signal molecule, but also serves as an information transfer molecule between plant individuals, that is, by releasing H₂S into the surrounding environment, plants under stress can provide early warning information of stress to their neighboring plants, which may be of great significance to the survival of the population.