Technische Universität München, Center of Life and Food Sciences Weihenstephan, Forest Genetics, Freising, Germany.
Plant Biol (Stuttg). 2011 May;13(3):445-52. doi: 10.1111/j.1438-8677.2010.00397.x. Epub 2010 Oct 29.
Wounding is a crucial threat to plants because of the physical damage caused and the possible entry of pathogens. Little is known about the wound reaction in forest trees. Therefore, leaves of young beech trees were wounded and the transcriptional response of wounded leaves and leaves directly above and below was analysed. A total of 123 genes exhibited significant regulation. The magnitude of regulation was slightly weaker in the downward leaves but the regulation pattern resembles that of the local and upward reactions. Thus, the signal was transduced in both vertical directions. Genes exhibiting major regulation lacked functional assignment or belonged to signalling, transcription and defence categories. Signalling included activation of transcripts in the calcium and ethylene pathways. There was also evidence for activation of jasmonic acid signalling, but no activation of jasmonic acid-responsive PR (pathogenesis-related) genes was observed. Moreover, repression of salicylic acid responsive defence was measured. Metabolic changes included induction of a core gene of the phenylpropanoid pathway, while energy metabolism exhibited down-regulation. These results support the conclusion that young beech trees might give up leaves and/or reduce leaf energy content after an attack so as to deprive a putative herbivore of a nutrient supply, instead of investing much energy in leaf defence.
创伤是植物面临的一个关键威胁，因为它会造成物理损伤，并可能导致病原体的入侵。目前人们对林木的创伤反应知之甚少。因此，本研究对幼山毛榉树的叶片进行了创伤处理，并分析了创伤叶片及其上下方叶片的转录组响应。共有 123 个基因表现出显著的调控。向下方叶片的调控幅度稍弱，但调控模式与局部和上方反应相似。因此，信号在垂直方向上都被传递。表现出主要调控的基因缺乏功能分配或属于信号转导、转录和防御类别。信号转导包括钙和乙烯途径中转录本的激活。也有证据表明茉莉酸信号的激活，但未观察到茉莉酸应答 PR（与发病相关）基因的激活。此外，还检测到水杨酸应答防御的抑制。代谢变化包括苯丙烷途径核心基因的诱导，而能量代谢表现出下调。这些结果支持这样的结论，即在受到攻击后，幼山毛榉树可能会放弃叶片和/或降低叶片的能量含量，从而剥夺潜在的食草动物的营养供应，而不是在叶片防御上投入大量能量。
