Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, PO Box 27, Helsinki 00014, Finland.
State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Lin'an District, Hangzhou, Zhejiang 311300, China.
Plant Cell Physiol. 2023 Oct 16;64(10):1204-1219. doi: 10.1093/pcp/pcad089.
Stilbenes accumulate in Scots pine heartwood where they have important roles in protecting wood from decaying fungi. They are also part of active defense responses, and their production is induced by different (a)biotic stressors. The specific transcriptional regulators as well as the enzyme responsible for activating the stilbene precursor cinnamate in the pathway are still unknown. UV-C radiation was the first discovered artificial stress activator of the pathway. Here, we describe a large-scale transcriptomic analysis of pine needles in response to UV-C and treatment with translational inhibitors, both activating the transcription of stilbene pathway genes. We used the data to identify putative candidates for the missing CoA ligase and for pathway regulators. We further showed that the pathway is transcriptionally activated by phosphatase inhibitor, ethylene and jasmonate treatments, as in grapevine, and that the stilbene synthase promoter retains its inducibility in some of the tested conditions in Arabidopsis, a species that normally does not synthesize stilbenes. Shared features between gymnosperm and angiosperm regulation and partially retained inducibility in Arabidopsis suggest that pathway regulation occurs not only via ancient stress-response pathway(s) but also via species-specific regulators. Understanding which genes control the biosynthesis of stilbenes in Scots pine aids breeding of more resistant trees.
芪类物质在苏格兰松心材中积累，在心材中它们在保护木材免受腐朽真菌侵害方面发挥着重要作用。芪类物质也是主动防御反应的一部分，其产生受不同（生物）胁迫源的诱导。该途径中负责激活芪类前体肉桂酸的特定转录调控因子和酶仍不清楚。UV-C 辐射是该途径中第一个被发现的人工胁迫激活剂。在这里，我们描述了对松针在 UV-C 和翻译抑制剂处理下的大规模转录组分析，这两种处理均能激活芪类途径基因的转录。我们利用这些数据鉴定了缺失的 CoA 连接酶和途径调控因子的可能候选物。我们进一步表明，该途径在磷酸酶抑制剂、乙烯和茉莉酸处理下被转录激活，与葡萄藤中的情况相同，并且在拟南芥中，一些测试条件下的芪合酶启动子保留了其诱导性，而拟南芥通常不合成芪类物质。松柏类和被子植物的调控具有共同特征，并且在拟南芥中部分保留了诱导性，这表明途径调控不仅通过古老的应激反应途径发生，还通过物种特异性调控因子发生。了解哪些基因控制苏格兰松芪类物质的生物合成有助于培育更具抗性的树木。
