The amazing ways plants defend themselves - Valentin Hammoudi

譯者: Marssi Draw 審譯者: Regina Chu

This is a tomato plant,

這棵是蕃茄

and this is an aphid slowly killing the tomato plant

這隻蚜蟲正慢慢吞噬這棵蕃茄

by sucking the juice out of its leaves.

透過吸取葉液讓它喪命

The tomato is putting up a fight using both physical and chemical defenses

蕃茄奮力運用身體和化學抵抗

to repel the attacking insects.

擊退來襲的昆蟲

But that's not all.

但還不止這些

The tomato is also releasing compounds that signal nearby tomato plants

這棵蕃茄還釋放出訊號 讓附近的蕃茄

to release their own insect repellent.

釋放出自製的驅蟲劑

Plants are constantly under attack.

植物不斷受到攻擊

They face threats ranging from microscopic fungi and bacteria,

它們受到的威脅 從微小的真菌、細菌

small herbivores, like aphids, caterpillars, and grasshoppers,

小型草食動物 如蚜蟲、毛蟲和蚱蜢

up to large herbivores, like tortoises, koalas, and elephants.

到大型草食動物 如烏龜、無尾熊和大象

All are looking to devour plants to access the plentiful nutrients

全都想一口吃掉這棵植物 攝取其中的豐沛養分

and water in their leaves, stems, fruits, and seeds.

以及莖葉、果實和種子裡的水分

But plants are ready with a whole series of internal and external defenses

但植物已經做好 裡裡外外的萬全準備來抵抗

that make them a much less appealing meal,

讓自己變得不那麼引人垂涎

or even a deadly one.

或是惹來殺身之禍

Plants' defenses start at their surface.

植物的防禦從表面開始

The bark covering tree trunks is full of lignin,

樹皮布滿了木質素

a rigid web of compounds that's tough to chew

嚴密的化合物網絡強壯到很難嚼

and highly impermeable to pathogens.

並且讓病原無縫可鑽

Leaves are protected by a waxy cuticle

葉子受到似蠟的角質層保護

that deters insects and microbes.

能夠驅逐昆蟲和微生物

Some plants go a step further with painful structures

有些植物更高竿 運用會痛死人的組織

to warn would-be predators.

來警告潛在的掠奪者

Thorns, spines, and prickles discourage bigger herbivores.

棘、針、刺讓大型草食動物知難而退

To deal with smaller pests, some plants' leaves have sharp hair-like structures

對付小害蟲

某些植物的葉子用尖銳的細毛組織

called trichomes.

稱為毛茸

The kidney bean plant sports tiny hooks to stab the feet of bed bugs

大紅豆植株讓芽變出小鉤子

and other insects.

來刺傷壞蟲和其它昆蟲的腳

In some species, trichomes also dispense chemical irritants.

某些物種的毛茸也會散發化學刺激物

Stinging nettles release a mixture of histamine and other toxins

異株蕁麻釋放出 含有組織胺和毒物的物質

that cause pain and inflammation when touched.

讓碰觸到它的動物疼痛、發炎

For other plant species, the pain comes after an herbivore's first bite.

還有些植物

讓草食動物啃下第一口才覺得痛

Spinach,

kiwi fruit,

波菜

奇異果

pineapple,

鳳梨

fuchsia

吊鐘花

and rhubarb all produce microscopic needle-shaped crystals called raphides.

和大黃都會製造微小針狀晶體

稱為針晶

They can cause tiny wounds in the inside of animals' mouths,

針晶會在動物嘴內製造很小的傷口

which create entry points for toxins.

讓毒物得以進入

The mimosa plant has a strategy designed to prevent herbivores

含羞草有高超的策略

阻止草食動物來咬它們

from taking a bite at all.

Specialized mechanoreceptor cells detect touch

特殊的機械性受器細胞偵測到觸碰

and shoot an electrical signal through the leaflet to its base

就從小葉片發射出電子訊號傳到底部

causing cells there to release charged particles.

讓細胞釋放出帶電粒子

The buildup of charge draws water out of these cells

充電的過程會將水抽出細胞

and they shrivel, pulling the leaflet closed.

然後闔起葉片，縮成一團

The folding movement scares insects away

這個關閉的動作會嚇跑昆蟲

and the shrunken leaves look less appealing to larger animals.

對大型動物來說 緊縮的葉片看起來也不太好吃

If these external defenses are breached,

如果這些外在防禦潰敗

the plant immune system springs into action.

植物的免疫系統就會起身而戰

Plants don't have a separate immune system like animals.

植物不像動物一樣 有單獨的免疫系統

Instead, every cell has the ability to detect and defend against invaders.

相反地，它們的每個細胞 都有能力偵測並抵抗外敵

Specialized receptors can recognize molecules that signal the presence

特殊的接收器可以辨識 發出立即訊號的分子

of dangerous microbes or insects.

告訴它們有微生物或昆蟲入侵的危險

In response, the immune system initiates a battery of defensive maneuvers.

免疫系統採取應對措施 啟動防禦機制

To prevent more pathogens from making their way inside,

防止更多病原體繼續入侵

the waxy cuticle thickens and cell walls get stronger.

似蠟的角質層變厚 細胞壁變得更堅固

Guard cells seal up pores in the leaves.

防護細胞緊閉葉中的氣孔

And if microbes are devouring one section of the plant,

如果微生物正在享用植物的某部分

那些細胞能自毀來隔離感染

those cells can self-destruct to quarantine the infection.

Compounds toxic to microbes and insects are also produced,

針對微生物和昆蟲的毒性化合物 也因應而生

often tailor-made for a specific threat.

常會為特殊威脅量身訂作

Many of the plant molecules that humans have adopted

許多被人類用來做為

as drugs, medicines and seasonings

藥材、草藥和調味料的植物分子

evolved as part of plants' immune systems because they're antimicrobial,

演化成植物免疫系統的一部分 因為它們抗菌

or insecticidal.

或能殺蟲

An area of a plant under attack can alert other regions using hormones,

植物受到攻擊的部分 可以警示其它部位

透過運用荷爾蒙 以空氣傳遞的化合物

airborne compounds,

or even electrical signals.

或甚至是電子訊號

When other parts of the plant detect these signals,

當植物其它部位偵測到這些訊號

they ramp up production of defensive compounds.

會增加防禦化合物的產量

And for some species, like tomatoes,

某些物種，像是蕃茄

this early warning system also alerts their neighbors.

這種即早警報系統 也會警告它們的鄰居

Some plants can even recruit allies to adopt a strong offense

某些植物甚至可以共組聯盟 形成超強防禦隊

against their would-be attackers.

共抵可能入侵的敵人

Cotton plants under siege by caterpillars

被毛蟲包圍的棉花植株

release a specific cocktail of ten to twelve chemicals into the air.

會在空氣中釋放某種混雜 10 到 12 種化學物質的化合物

This mixture attracts parasitic wasps that lay eggs inside the caterpillars.

這種混合物吸引寄生蜂 下蛋在毛蟲體內

Plants may not be able to flee the scene of an attack,

植物可能沒辦法逃離攻擊現場

or fight off predators with teeth and claws,

或是用齜牙利爪擊退捕食者

but with sturdy armor,

但有了堅固的盔甲

a well-stocked chemical arsenal,

滿滿的化學兵工廠

a neighborhood watch,

相互照看的鄰居

and cross-species alliances,

和跨物種聯盟

a plant isn't always an easy meal.

讓自己不再輕易落入虎口