六级听力：谁在啃我的叶子!

Plants Arming Themselves

植物的自我武装

Yaël: Don, imagine this scenario. You're a plant, and a butterfly lays its eggs on you. What do you do?
Don，试想一下这样的情景：你是一株植物，一只蝴蝶在你的叶子上产下了很多的卵，作为植物的你会做什么呢？

Don: What can I do Yaël, I'm a plant. I have roots, I think I'm stuck.
你说我能做什么呢，我是株植物，我是有根的，被死死固定在泥土里。

Y: Actually, Don, it turns out that you can do plenty.
事实上，你可以做很多事情。

D: Even with caterpillars gnawing on my leaves?
即使毛毛虫在啃我的叶子？

Y: Especially them, you see plants aren't as static as you think they are. In fact, some plants are so tuned into their predators that they know exactly what kind of insect is munching on their leaves.
特别是这种情况，你要知道植物并非你所想的那样一直静止不动。事实上，许多植物对其天敌相当敏感，所以能很清楚地辨识出是什么昆虫在啃食自己的叶子。

D: Like whether it's a caterpillar or a beetle? Amazing!
能辨识出是毛毛虫还是甲虫？太神奇啦！

Y: And this means that individual plants can also adjust their physiology in response to their current conditions. So they may release substances that are toxic to the particular insect, adjust the ways they look and smell, and even adjust their growth patterns.
这意味着单株植物能根据眼前的情况调整自身的生理学特征——释放对特定昆虫有毒的物质、改变自身的形态、散发不同的气味、甚至于改变自身的生长模式。

D: Really?
真的吗？

Y: And this can work both for and against the other species, depending on whether the plant needs its help. For example, plants being attacked by an insect might release scents that attract the predators of that insect. And don't think the insects don't adjust in return. For example, they may adjust the balance of enzymes in their stomach in order to better digest the plant.
这样的改变对其他的物种有好处也有坏处，这取决于该植物是否能获得益处。比如说，某种植物被昆虫攻击时可能会释放出能引来该种昆虫天敌的气味。但是，不要认为昆虫都是“傻子”，它们也会进行相应的调整。例如，昆虫会改变胃液中消化酶的平衡以此更好地消化植物。

D: So it's like the plants and the insects are engaged in some elaborate arms race.
那这样说来，岂不是说植物与昆虫都“醉心于”一场“精锐武器”大赛！