Jehnes S, Betz G, Bahnweg G, Haberer K, Sandermann H, Rennenberg H
Institute of Forest Botany and Tree Physiology, Albert Ludwigs University Freiburg, Georges-Köhler-Allee 053/054, 79110 Freiburg, Germany.
Plant Biol (Stuttg). 2007 Mar;9(2):253-64. doi: 10.1055/s-2006-924650.
The influence of free-air ozone (O(3)) fumigation on the levels of gene transcripts and compounds of defence and signalling were analysed in leaves of adult beech trees from the "Kranzberg Forest" research site in 2003 and 2004. This includes the precursor of the stress hormone ethylene, ACC (1-aminocyclopropane-1-carboxylic acid), conjugated salicylic acid, lignin content as well as of the expression level of genes connected with oxidative stress and stress signalling. At this site mature beech trees were exposed to an enhanced O(3) regime by a free-air O(3) canopy exposure system. Levels of conjugated ACC and conjugated salicylic acid in leaves were increased under O (3) fumigation whereas lignin content was only slightly enhanced. Quantitative real-time RT-PCR (qRT-PCR) was performed on transcripts of genes connected with lignin, salicylic acid, and ethylene formation, the shikimate pathway, abscisic acid biosynthesis as well as with the antioxidative system. Genes which showed O(3)-dependent increases included FSCOMT (caffeic-acid O-methyltransferase) connected with lignin formation, the stress response genes FSACS2 (ACC synthase) and FSPR1 (PR10 - pathogenesis-related protein), as well as FSNCED1 (9-cis-epoxicarotenoid dioxygenase), the rate-limiting enzyme of the ABA synthesis. For FSNCED1 expression level, a significant O(3) effect was found with an 8-fold (sun) and 7-fold (shade) induction in July 2003 and a 3-fold and 2.5-fold induction in July 2004. While the observed effects were not continuous, elevated O(3) is concluded to have the potential to disrupt the defence and signalling system.
2003年和2004年，在“克兰茨贝格森林”研究地点，对成年山毛榉树叶片进行了分析，研究了自由大气臭氧（O₃）熏蒸对防御和信号传导相关基因转录本水平及化合物的影响。这包括应激激素乙烯的前体ACC（1-氨基环丙烷-1-羧酸）、结合态水杨酸、木质素含量，以及与氧化应激和应激信号传导相关基因的表达水平。在该地点，成熟的山毛榉树通过自由大气臭氧冠层暴露系统暴露于增强的O₃环境中。在O₃熏蒸下，叶片中结合态ACC和结合态水杨酸的水平升高，而木质素含量仅略有增加。对与木质素、水杨酸和乙烯形成相关基因的转录本、莽草酸途径、脱落酸生物合成以及抗氧化系统进行了定量实时RT-PCR（qRT-PCR）分析。显示出O₃依赖性增加的基因包括与木质素形成相关的FSCOMT（咖啡酸O-甲基转移酶）、应激反应基因FSACS2（ACC合酶）和FSPR1（PR10 - 病程相关蛋白），以及FSNCED1（9-顺式环氧类胡萝卜素双加氧酶），它是ABA合成的限速酶。对于FSNCED1的表达水平，在2003年7月发现了显著的O₃效应，有8倍（阳光照射）和7倍（遮荫）的诱导，在2004年7月有3倍和2.5倍的诱导。虽然观察到的效应不连续，但可以得出结论，升高的O₃有可能破坏防御和信号系统。
