Homeostasis in plants · 植物中的稳态
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| stomata/ˈstəʊmətə/ | 气孔 | qì kǒng |
| transpiration/trænspəˈreɪʃn/ | 蒸腾作用 | zhēng téng zuò yòng |
| guard cell/ɡɑːd sel/ | 保卫细胞 | bǎo wèi xì bāo |
| turgid/ˈtɜːdʒɪd/ | 膨胀 | péng zhàng |
| water stress/ˈwɔːtə stres/ | 水分胁迫 | shuǐ fèn xié pò |
| abscisic acid/əbˈsɪzɪk ˈæsɪd/ | 脱落酸 | tuō luò suān |
How plants control water loss
- Stomata 气孔 are pores in a leaf.
- The plant opens and closes them to balance two needs.
- A drought hormone can shut them to save water.
植物如何控制水分损失
- 气孔(stomata) 是叶中的孔。
- 植物打开和关闭它们以平衡两种需求。
- 一种干旱激素能关闭它们以节省水。
Guard cells close the stomata to reduce water loss when the plant is short of water. · 当植物缺水时,保卫细胞关闭气孔以减少水分损失。
Closing the stomata is how a plant conserves water — part of homeostasis in plants. · 关闭气孔是植物保存水的方式——植物中稳态的一部分。
A plant opens and closes its stomata to balance: · 一株植物打开和关闭它的气孔以平衡:
Open stomata let CO₂ in for photosynthesis but also let water escape, so the plant must balance the two. · 张开的气孔让 CO₂ 进来用于光合作用,但也让水逃逸,所以植物必须平衡两者。
A balancing act
- Open stomata let in carbon dioxide for photosynthesis.
- But open stomata also lose water by transpiration 蒸腾作用.
- So stomata usually open by day and close at night, on a daily rhythm.
一种平衡
- 张开的气孔让 二氧化碳 进来用于 光合作用。
- 但张开的气孔也通过 蒸腾 损失 水。
- 所以气孔通常 白天打开、夜晚关闭,有一个每日的节律。
How a stoma opens · 一个气孔如何打开
Step through it. Guard cells pump in ions, draw in water by osmosis, swell turgid and bend apart — opening the pore. · 一步步走过它。保卫细胞泵入离子,通过渗透吸入水,膨胀坚挺并弯曲分开——打开孔。
Guard cells open a stoma by: · 保卫细胞通过以下打开一个气孔:
Taking in ions lowers their water potential; water enters, the guard cells swell turgid and bend apart. · 摄入离子降低它们的水势;水进入,保卫细胞膨胀坚挺并弯曲分开。
Put the opening of a stoma in order. · 把一个气孔的打开按顺序排列。
Pump ions → water in by osmosis → turgid → bend apart → open. Losing the ions reverses it and the stoma closes. · 泵离子 → 水通过渗透进入 → 坚挺 → 弯曲分开 → 打开。失去离子逆转它,气孔关闭。
How guard cells 保卫细胞 work
- Each stoma is opened and closed by two guard cells:
- to open: guard cells pump in ions → water potential falls → water enters by osmosis → they swell turgid 膨胀 and bend apart, opening the pore.
- to close: ions leave → water follows out → guard cells go floppy → the pore shuts.
Guard cells swell turgid to open the stoma, and go floppy to close it
保卫细胞如何工作
- 每个气孔由两个 保卫细胞(guard cells) 打开和关闭:
- 要 打开:保卫细胞泵入离子 → 水势下降 → 水通过渗透进入 → 它们膨胀 坚挺(turgid) 并弯曲分开,打开孔。
- 要 关闭:离子离开 → 水随之出去 → 保卫细胞变 松软 → 孔关闭。
保卫细胞膨胀坚挺以打开气孔,变松软以关闭它
When a plant is short of water, abscisic acid (ABA): · 当一株植物缺水时,脱落酸(ABA):
ABA is released under water stress and triggers stomatal closure to conserve water. · ABA 在水分胁迫下被释放,并触发气孔关闭以保存水。
When a plant is short of water, the hormone ______ makes its stomata close. · 当一株植物缺水时,激素 ______ 使它的气孔关闭。
ABA is the stress hormone that triggers stomatal closure to save water. · ABA 是触发气孔关闭以节省水的胁迫激素。
Inside the guard cells, the second messenger in ABA signalling is: · 在保卫细胞内部,ABA 信号传递中的第二信使是:
Calcium ions act as the second messenger that brings about stomatal closure in response to ABA. · 钙离子充当响应 ABA 而引起气孔关闭的第二信使。
Water stress 水分胁迫 and ABA
- When the plant is short of water (water stress), it releases the hormone abscisic acid 脱落酸 (ABA).
- ABA makes the guard cells lose ions and water, so the stomata close and save water.
- Inside the guard cells, calcium ions act as a second messenger.
水分胁迫和 ABA
- 当植物缺水(水分胁迫(water stress))时,它释放激素 脱落酸(abscisic acid,ABA)。
- ABA 使保卫细胞失去离子和水,所以气孔 关闭 并节省水。
- 在保卫细胞内部,钙离子 充当一个 第二信使。
You've got it
- stomata balance CO₂ in (photosynthesis) vs water loss (transpiration)
- guard cells open the pore by taking in ions + water (turgid); close it by losing them (floppy)
- under water stress, ABA makes stomata close to save water
- calcium ions act as the second messenger in the guard cells
你掌握了
- 气孔 平衡 CO₂ 进来(光合作用)对 水分损失(蒸腾)
- 保卫细胞 通过摄入离子 + 水打开孔(坚挺);通过失去它们关闭它(松软)
- 在 水分胁迫 下,ABA 使气孔 关闭 以节省水
- 钙离子 充当保卫细胞中的 第二信使