Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Phytochemistry. 2021 Jul;187:112768. doi: 10.1016/j.phytochem.2021.112768. Epub 2021 Apr 28.
Plant defensive mimicry based on the aphid alarm pheromone (E)-β-farnesene (EβF) was previously shown to operate in Tanacetum cinerariifolium (Asteraceae) flowers. Germacrene D (GD), is another dominant volatile of T. cinerariifolium flowers and may modulate both defense and pollination. Here, we find that the increase in GD/EβF ratio at later developmental stages is correlated with the tissue distribution in the flower head: the total content of EβF and GD is similar, but GD accumulates comparatively more in the upper disk florets. Naphthol and N, N-dimethyl-p-phenylenediamine dihydrochloride (NADI)-stained purple ducts containing EβF and GD, were observed in the five petal lips of the corolla and two-lobed stigma of disk florets. By contrast in the peduncle, EβF accounts for nearly 80% of total terpenes, compared to 5% for GD. EβF is accumulated inside inner cortex cells and parenchyma cells of the pith in young peduncle. This is followed by the formation of terpene-filled axial secretory cavities parallel to the vascular bundles. In conclusion, the observed developmental and diurnal emissions of different EβF/GD ratios appear to be regulated by their tissue distribution.
先前的研究表明，基于蚜虫报警信息素（E）-β-法尼烯（EβF）的植物防御拟态存在于菊科蓝蓟属植物的花朵中。大根香叶烯 D（GD）是蓝蓟属植物花朵的另一种主要挥发性物质，可能调节防御和授粉。在这里，我们发现随着花发育后期的进行，GD/EβF 比值的增加与花头部的组织分布有关：EβF 和 GD 的总含量相似，但 GD 在上面的盘状小花中积累相对较多。在花瓣的 5 个唇瓣和盘状小花的 2 裂柱头中观察到含有 EβF 和 GD 的萘酚和 N，N-二甲基对苯二胺二盐酸盐（NADI）染色的紫色导管。相比之下，在花梗中，EβF 占萜类化合物总量的近 80%，而 GD 仅占 5%。EβF 积累在年轻花梗的内皮层细胞和髓质细胞内。随后，形成与维管束平行的充满萜类的轴向分泌腔。总之，观察到的不同 EβF/GD 比值的发育和日变化排放似乎受到它们的组织分布的调节。
