Department of Childhood Education, School of Education, Miyazaki International College, 1405 Kano, Kiyotake-cho, Miyazaki 889-1605, Japan.
Department of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.
Biol Lett. 2022 Oct;18(10):20220373. doi: 10.1098/rsbl.2022.0373. Epub 2022 Oct 26.
Certain plants exhibit rapid movement in response to mechanical stimulation; however, the ecological functions of this behaviour are largely unknown. Here, we show that the rapid flower closure of (Droseraceae) in response to mechanical stimulation functions as a physical defence against a specialist herbivore (Pterophoridae) caterpillar. Following feeding damage on fruits, flowers, flower stalks and buds by , closed its flowers nine times faster than during natural circadian closure. The extent of damage to ovules was significantly reduced when the flowers were able to close compared with the condition in which closure was physically inhibited by the application of a resin. Nonetheless, flower closure had no effect on the feeding damage to stamens and styles and promoted further damage to petals. Given that feeding on petals, stamens and styles had no significant effect on the number of mature seeds, rapid flower closure leading to the protection of ovules had an overall positive effect on the reproductive success of . Our study showed rapid plant movement as a novel case of induced physical defence against herbivory.
某些植物会对机械刺激表现出快速的运动反应；然而，这种行为的生态功能在很大程度上是未知的。在这里，我们表明，对机械刺激的快速花朵关闭反应在功能上是对专食性鳞翅目毛毛虫（Pterophoridae）幼虫的物理防御。在 （Droseraceae）果实、花朵、花梗和花蕾受到 的取食损害后，与自然昼夜节律关闭相比，花朵关闭的速度快了九倍。与通过施加树脂物理抑制关闭的情况相比，当花朵能够关闭时，对胚珠的损害程度显著降低。尽管如此，花朵关闭对雄蕊和雌蕊的取食损害没有影响，并促进了花瓣的进一步损害。鉴于对花瓣、雄蕊和雌蕊的取食对成熟种子的数量没有显著影响，快速的花朵关闭导致对胚珠的保护对 的繁殖成功有整体积极影响。我们的研究表明，植物的快速运动是一种针对食草动物的新的诱导物理防御案例。
