中文导读 被风暴推倒或长在陡坡上的树，为什么能慢慢把树干重新“掰直”？文章先提出这个现象，再交代背景：植物能感知自身形状，但这种感觉如何变成运动一直是个谜。接着介绍研究人员如何用一台不停转动、四面均匀打光的装置排除重力和光线的影响，然后讲主要发现：树会在茎的另一侧长出新的应拉木，像一对相互对抗的肌肉。最后说明这一发现对木材和谷物种植可能有什么用。阅读时可留意 yet、however、so、because 如何连接现象与原因，以及 suggests、may、could 如何表示研究结论的边界。
正文 A tree that grows on a steep hill or gets pushed over by a storm often ends up with a bent trunk . Yet many trees slowly become straight again . A new study from France helps explain how they do it , and the answer looks like the way animals use muscles
本段译文 长在陡坡上或被风暴推倒的树，树干常常会弯曲。然而，许多树会慢慢重新变直。法国的一项新研究有助于解释它们是怎么做到的，而答案看起来很像动物使用肌肉的方式。
For years , scientists have known that plants can feel their own shape . This sense , called proprioception , was once thought to exist only in animals . In 2012, researchers working with INRAE , a French research institute , showed that plants have it too . However , no one knew how a plant turned this feeling into real movement
本段译文 多年来，科学家已经知道植物能感知自身的形状。这种感觉被称为本体感觉，人们曾认为只有动物才有。2012 年，与法国研究机构 INRAE 合作的研究人员证明，植物也有这种能力。然而，没有人知道植物如何把这种感觉转化为真正的运动。
To find out , the team had to remove the other signals that guide plant growth . Plants normally grow toward light and react to gravity . So the researchers built an unusual machine . Young poplar trees lay on a flat platform that kept turning slowly inside a ball lit equally from every side . Because the trees kept turning and the light came from everywhere , they could not tell which way was up .
本段译文 为了弄清楚这一点，研究团队必须去掉其他引导植物生长的信号。植物通常朝光生长，并对重力作出反应。因此，研究人员制作了一台不同寻常的装置。幼小的杨树躺在一个平台上，平台在一个从各个方向均匀照亮的球体内缓慢地不停转动。由于树一直在转动，光又来自四面八方，它们无法分辨哪边是上方。
First , the young trees were laid on their sides and allowed to grow . Their stems curved upward toward the sky . This happens because of a special kind of wood called tension wood . When it forms on the upper side of a stem , it pulls like a muscle and bends the stem up . After about ten days , the curved trees were moved into the machine . Over the next few weeks , their stems slowly became almost straight again .
本段译文 首先，研究人员把幼树侧放，让它们生长。它们的茎向上朝天空弯曲。这是因为一种叫作应拉木的特殊木材。当它在茎的上侧形成时，会像肌肉一样拉动，把茎向上弯。大约十天后，这些弯曲的树被移进装置中。在接下来的几周里，它们的茎慢慢变得几乎重新笔直。
When the scientists studied the new wood , they found something surprising . Tension wood had stopped growing on the upper side and had started to form on the opposite side . This new wood pulled in the other direction , much like two opposing muscles in an arm . Before this study , scientists believed tension wood formed only on the upper side of stems
本段译文 科学家研究新长出的木材时，发现了令人意外的情况。应拉木在上侧停止生长，并开始在相对的一侧形成。这些新木材朝另一个方向拉，很像手臂中两块相互对抗的肌肉。在这项研究之前，科学家认为应拉木只会在茎的上侧形成。
The research published in the journal New Phytologist , suggests that trees use their sense of shape to decide where this wood should grow . Bruno Moulia , a research director at INRAE , described it as a real “sensorimotor loop “ working in trees .
本段译文 这项发表在《新植物学家》（New Phytologist）期刊上的研究表明，树会利用对自身形状的感知来决定这种木材应该长在哪里。INRAE 研究主任布鲁诺·穆利亚（Bruno Moulia）将其描述为在树木中运作的真正的“感觉—运动回路”。
The findings may also have practical uses . Badly timed tension wood can leave too much stress inside a tree and lower the quality of its wood . By choosing plants that sense their shape well , scientists may be able to grow straighter trees for timber . The same idea could help develop grain crops that are less likely to fall over before harvest
本段译文 这些发现也可能有实际用途。应拉木形成的时机不当，会在树内部留下过多应力，降低木材质量。通过挑选能很好感知自身形状的植物，科学家或许能够培育出更直的用材树。同样的思路也可能帮助培育在收获前不容易倒伏的谷物作物。
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