2j - Plant Coordination

Auxin

生长素 (shēngzhǎngsù) A type of plant hormone primarily responsible for cell elongation in shoots and inhibiting cell elongation in roots; involved in phototropism, gravitropism, and other growth responses.

Clinostat

旋转器 (xuánzhuǎnqì) / 回转器 (huízhuǎnqì) An apparatus that slowly rotates a plant, used in experiments to distribute the effect of a unidirectional stimulus (like light or gravity) evenly, to study its effect on tropisms.

Coleoptile

胚芽鞘 (pēiyáqiào) A protective sheath covering the emerging shoot tip (plumule) in grass seedlings; often used in experiments on phototropism because it's very sensitive to light and produces auxin.

Differential Growth

差异生长 (chāyì shēngzhǎng) Unequal rates of cell growth or elongation on opposite sides of a plant organ (e.g., stem or root), causing it to bend or curve. This is the mechanism behind tropisms.

Epinasty

偏上性 (piānshàngxìng) / 上偏生长 (shàngpiān shēngzhǎng) Downward bending of a plant part, often leaves or petals, typically caused by a higher rate of cell elongation on the upper side compared to the lower side. Can be influenced by hormones like ethylene.

Gravitropism (Geotropism)

向重力性 (xiàng zhònglìxìng) / 向地性 (xiàngdìxìng) A plant's growth response to the stimulus of gravity. Shoots typically show negative gravitropism (grow upwards, away from gravity), while roots show positive gravitropism (grow downwards, towards gravity).

Hormone

植物激素 (zhíwù jīsù) Chemical messengers produced by plants that regulate their growth, development, and responses to environmental stimuli. They are effective in very small concentrations.

Hydrotropism

向水性 (xiàngshuǐxìng) A plant's growth response (usually of roots) towards a source of water.

Phototropism

向光性 (xiàngguāngxìng) A plant's growth response to the stimulus of light. Shoots typically show positive phototropism (grow towards light), while roots may show negative phototropism or be insensitive.

Shoot Apex (Apical Bud)

茎尖 (jīngjiān) / 顶芽 (dǐngyá) The tip of a plant shoot, containing meristematic tissue where cell division occurs and auxins are produced, influencing growth and tropisms.

Stimulus

刺激 (环境) (cìjī (huánjìng)) Any change in an organism's internal or external environment that can cause a response (e.g., light, gravity, water, touch for plants).

Thigmotropism

向触性 (xiàngchùxìng) A plant's growth response to physical touch or contact, such as tendrils coiling around a support.

Tropism

向性运动 (xiàngxìng yùndòng) / 向性 (xiàngxìng) A directional growth response of a plant, or part of a plant, towards or away from an external stimulus.