Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Sci Rep. 2020 Oct 14;10(1):17196. doi: 10.1038/s41598-020-74144-3.
Flowers of fragrant roses such as Rosa bourboniana are ethylene-sensitive and undergo rapid petal abscission while hybrid roses show reduced ethylene sensitivity and delayed abscission. To understand the molecular mechanism underlying these differences, a comparative transcriptome of petal abscission zones (AZ) of 0 h and 8 h ethylene-treated flowers from R. bourboniana was performed. Differential regulation of 3700 genes (1518 up, 2182 down) representing 8.5% of the AZ transcriptome was observed between 0 and 8 h ethylene-treated R. bourboniana petal AZ. Abscission was associated with large scale up-regulation of the ethylene pathway but prominent suppression of the JA, auxin and light-regulated pathways. Regulatory genes encoding kinases/phosphatases/F-box proteins and transcription factors formed the major group undergoing differential regulation besides genes for transporters, wall modification, defense and phenylpropanoid pathways. Further comparisons with ethylene-treated petals of R. bourboniana and 8 h ethylene-treated AZ (R. hybrida) identified a core set of 255 genes uniquely regulated by ethylene in R. bourboniana AZ. Almost 23% of these encoded regulatory proteins largely conserved with Arabidopsis AZ components. Most of these were up-regulated while an entire set of photosystem genes was prominently down-regulated. The studies provide important information on regulation of petal abscission in roses.
香玫瑰（如 Bourbon 蔷薇）的花朵对乙烯敏感，会迅速发生花瓣脱落，而杂种玫瑰对乙烯的敏感性降低，脱落延迟。为了了解这些差异的分子机制，对 Bourbon 蔷薇花瓣离区（AZ）在 0 小时和 8 小时乙烯处理后的转录组进行了比较分析。在 Bourbon 蔷薇花瓣 AZ 中，0 小时和 8 小时乙烯处理之间观察到 3700 个基因（1518 个上调，2182 个下调）的差异调节，代表 AZ 转录组的 8.5%。离区与乙烯途径的大规模上调有关，但 JA、生长素和光调控途径显著受到抑制。除了转运蛋白、细胞壁修饰、防御和苯丙烷途径的基因外，编码激酶/磷酸酶/F-box 蛋白和转录因子的调控基因是差异调节的主要群体。与 Bourbon 蔷薇乙烯处理的花瓣和 8 小时乙烯处理的 AZ（R. hybrida）进一步比较，确定了 Bourbon 蔷薇 AZ 中乙烯特有的 255 个核心基因。这些基因编码的调节蛋白中有近 23%与拟南芥 AZ 成分高度保守。这些基因大多数上调，而一整套光合作用基因则明显下调。这些研究为玫瑰花瓣脱落的调控提供了重要信息。
