Department of Agriculture, Food and Environment, Università degli Studi di Pisa, Pisa, Italy,
Plant Mol Biol. 2015 Jan;87(1-2):169-80. doi: 10.1007/s11103-014-0268-8. Epub 2014 Nov 26.
Flower senescence is a fascinating natural process that represents the final developmental stage in the life of a flower. Plant hormones play an important role in regulating the timing of flower senescence. Ethylene is a trigger and usually accelerates the senescence rate, while cytokinins are known to delay it. The aim of this work was to study the effect of 6-benzylaminopurine (BA) on petal senescence by transcript profile comparison after 3 or 6 h using a cross-species method by hybridizing petunia samples to a 4 × 44 K Agilent tomato array. The relative content of ethylene, abscisic acid, anthocyanins, total carotenoids and total phenols that determine the physiological behaviours of the petal tissue were measured. BA treatment prolonged the flower life and increased the concentrations of phenols and anthocyanins, while total carotenoids did not increase and were lower than the control. The ethylene biosynthetic and perception gene expressions were studied immediately after treatment until 24 h and all genes were repressed, while ethylene production was strongly induced after 4 days. The microarray analyses highlighted that BA strongly affected gene regulation after 3 h, but only 14% of genes remained differentially expressed after 6 h. The most affected pathways and genes were those related to stress, such as heat shock proteins, abscisic acid (ABA) catabolism and its signalling pathway, lipid metabolism and antioxidant defence systems. A gene annotation enrichment analysis using DAVID showed that the most important gene clusters were involved in energy generation and conservation processes. In addition to the ethylene pathway, cytokinins seem to be strongly involved the regulation of the ABA response in flower tissues.
花衰老（Flower senescence）是一个迷人的自然过程，代表了花生命的最后一个发育阶段。植物激素在调节花衰老的时间方面起着重要作用。乙烯（Ethylene）是一个触发因素，通常会加速衰老速度，而细胞分裂素（Cytokinins）则被认为可以延缓衰老。本研究旨在通过杂交矮牵牛样品到 4×44K Agilent 番茄微阵列的跨物种方法，使用转录谱比较研究 6-苄基氨基嘌呤（BA）对花瓣衰老的影响，在 3 或 6 小时后进行。通过测量决定花瓣组织生理行为的乙烯、脱落酸、花青素、类胡萝卜素和总酚的相对含量来确定。BA 处理延长了花期并增加了酚类和花青素的浓度，而总类胡萝卜素没有增加，反而低于对照。立即研究处理后 24 小时内乙烯生物合成和感知基因的表达，所有基因均被抑制，而 4 天后乙烯的产生则被强烈诱导。微阵列分析突出表明，BA 在 3 小时后强烈影响基因调控，但在 6 小时后只有 14%的基因仍然存在差异表达。受影响最大的途径和基因是与应激相关的途径和基因，如热休克蛋白、脱落酸（ABA）代谢及其信号通路、脂质代谢和抗氧化防御系统。使用 DAVID 进行基因注释富集分析表明，最重要的基因簇与能量生成和保存过程有关。除了乙烯途径外，细胞分裂素似乎也强烈参与了花组织中 ABA 反应的调节。
