中國最美的尼姑庵，不燒香只種花，看一眼就想出家！明星也慕名而來……
一年生植物的策略是隻在雨季生長。
At the end of that season they produce a seed, which is dry, eight to 10 percent water, but very much alive.
在雨季結束的時候，它們產生種子，種子很乾燥，只含有8%到10%的水，但卻生機勃勃。
And anything that is that dry and still alive, we call desiccation-tolerant.
這樣在乾燥環境下仍保持活性的性質叫做乾燥耐受。
In the desiccated state, what seeds can do is lie in extremes of environment for prolonged periods of time.
在乾燥的國家種子在如此極端環境下可以存活很長的一段時間。
The next time the rainy season comes, they germinate and grow, and the whole cycle just starts again.
下次雨季來臨時，它們馬上發芽生長，如此循環往復。
It's widely believed that the evolution of desiccation-tolerant seeds allowed the colonization and the radiation of flowering plants, or angiosperms, onto land.
普遍認爲正是進化出這樣乾燥耐受的種子才讓開花植物和被子植物在陸地上的定植和傳播成爲可能。
But back to annuals as our major form of food supplies.
作爲主要食物來源的一年生植物，
Wheat, rice and maize form 95 percent of our plant food supplies.
比如構成我們食物來源95%的小麥，水稻和玉米。
And it's been a great strategy because in a short space of time you can produce a lot of seed.
這看起來也是一個很好的策略，因爲短時間內就可以生產大量的種子。
Seeds are energy-rich so there's a lot of food calories, you can store it in times of plenty for times of famine, but there's a downside.
種子富含可以被人體吸收的能量，所以你可以在食物充足的時候爲饑荒做準備，但是也有不足之處。
The vegetative tissues, the roots and leaves of annuals, do not have much by way of inherent resistance, avoidance or tolerance characteristics.
這些植物的營養組織根部和葉片並沒有什麼抵抗乾燥，避免乾燥或者耐受乾燥的特性。
They just don't need them.
因爲它們根本不需要。
They grow in the rainy season and they've got a seed to help them survive the rest of the year.
它們本來就生長在雨季，而且已經生產了可以度過餘下時間的種子。
And so despite concerted efforts in agriculture to make crops with improved properties of resistance,
而且無論農業專家如何努力提升農作物的抵抗、
avoidance and tolerance -- particularly resistance and avoidance because we've had good models to understand how those work -- we still get images like this.
避免和耐受乾旱的能力——尤其是抵抗和避免乾旱的能力，儘管我們已經有了很好的模型來了解植物的運作模式，我們仍然只得到了這樣的結果。
Maize crop in Africa, two weeks without rain and it's dead.
非洲的玉米作物經歷兩週不下雨之後就死了。
There is a solution: resurrection plants.
現在有一個方案就是復甦植物。
These plants can lose 95 percent of their cellular water, remain in a dry, dead-like state for months to years, and give them water,
這些植物可以失去95%的細胞水分進入乾燥的假死狀態長達數月之久，只要給它們水，
they green up and start growing again.
它們馬上就可以變綠開始生長。
Like seeds, these are desiccation-tolerant.
像種子一樣，它們擁有乾燥耐受性。
Like seeds, these can withstand extremes of environmental conditions.
就像種子一樣，它們可以經受住極端的環境條件。
And this is a really rare phenomenon.
這是一種非常罕見的現象。
There are only 135 flowering plant species that can do this.
全世界只有135種開花植物可以做到。
I'm going to show you a video of the resurrection process of these three species in that order.
我將給各位放一段三種復甦植物復甦過程的視頻。
And at the bottom, there's a time axis so you can see how quickly it happens.
在視頻下方有一個時間軸，各位可以看到一切發生得多麼迅速。
Pretty amazing, huh?
很神奇是吧？
So I've spent the last 21 years trying to understand how they do this.
因此，在過去的21年裏，我一直在試圖瞭解它們是如何做到這一點的？
How do these plants dry without dying?
這些植物怎樣才能做到幹而不死呢？
And I work on a variety of different resurrection plants, shown here in the hydrated and dry states, for a number of reasons.
因爲很多原因，我研究了圖中不同的復甦植物在乾燥和有水環境下的狀態。
One of them is that each of these plants serves as a model for a crop that I'd like to make drought-tolerant.
其中一個原因是每一種復甦植物都可以作爲一種農作物的耐旱版本的模板。
So on the extreme top left, for example, is a grass, it's called Eragrostis nindensis,
比如左上角這種草，叫做畫眉蟲草，
it's got a close relative called Eragrostis tef -- a lot of you might know it as "teff" -- it's a staple food in Ethiopia, it's gluten-free,
它是苔麩的近親，也就是很多人熟知的埃塞俄比亞畫眉草，那是埃塞俄比亞的主要作物，它不含谷蛋白，
and it's something we would like to make drought-tolerant.
我們想開發耐旱版本的埃塞俄比亞畫眉草。
The other reason for looking at a number of plants, is that, at least initially, I wanted to find out: do they do the same thing?
另一個我們研究其它各種各樣的植物的原因是，至少我們希望從本質上了解它們在做同樣的事情麼？
Do they all use the same mechanisms to be able to lose all that water and not die?
它們可以做到失水而不死的內在機制是相同的麼？
So I undertook what we call a systems biology approach in order to get a comprehensive understanding of desiccation tolerance,
所以我採用系統生物學方法，希望對植物的耐旱性有一個全面的瞭解，
in which we look at everything from the molecular to the whole plant, ecophysiological level.
系統生物學方法就是從分子層面到整體植株生理生態層面的整體研究。
For example we look at things like changes in the plant anatomy as they dried out and their ultrastructure.
比如我們通過解剖觀察干枯的植物的變化和它們的亞顯微結構。
We look at the transcriptome, which is just a term for a technology in which we look at the genes that are switched on or off, in response to drying.
我們觀察轉錄組如何應對乾旱，轉錄組是一個技術術語，意思是我們觀察基因開關在應對乾旱時是開啓還是關閉。
Most genes will code for proteins, so we look at the proteome.
大部分基因會製造蛋白質，所以我們研究蛋白質組。
What are the proteins made in response to drying?
乾旱來臨時植物會製造什麼蛋白質？
Some proteins would code for enzymes which make metabolites, so we look at the metabolome.
一些蛋白質會製造讓植物新陳代謝的酶，所以我們研究代謝組。
Now, this is important because plants are stuck in the ground.
這很重要，因爲植物都是固定在土地之上的。
They use what I call a highly tuned chemical arsenal to protect themselves from all the stresses of their environment.
它們利用所謂的高度協調的化工廠保護它們不受外界環境的壓力。
So it's important that we look at the chemical changes involved in drying.
所以研究這些因爲乾燥引起的化學變化也非常重要。
And at the last study that we do at the molecular level, we look at the lipidome -- the lipid changes in response to drying.
最後我們在分子層面的研究中，我們研究了脂質體脂質是如何變化以應對乾旱的。
And that's also important because all biological membranes are made of lipids.
這一點也很重要，因爲所有的生物膜都是由脂類組成的。
They're held as membranes because they're in water.
因爲在水中所以它們保持膜狀。
Take away the water, those membranes fall apart.
脫離水後這些膜就會破碎。
Lipids also act as signals to turn on genes.
脂質同樣是開啓基因的信號。
Then we use physiological and biochemical studies to try and understand the function of the putative protectants that we've actually discovered in our other studies.
我們運用生理和生化研究方法去試驗和了解我們已經在其他研究中發現的假定保護機制。
And then use all of that to try and understand how the plant copes with its natural environment.
通過這些所有的研究來嘗試理解植物如何適應它周圍的自然環境。
I've always had the philosophy that I needed a comprehensive understanding of the mechanisms of desiccation tolerance in order to make a meaningful suggestion for a biotic application.
我的科學哲學是我需要對耐旱性的機制有全面的理解纔可以給出對於生物應用的有意義的建議。
I'm sure some of you are thinking, "By biotic application, does she mean she's going to make genetically modified crops?"
我確信有一些人在想“她所說的生物應用是不是意味着轉基因作物呢？”
And the answer to that question is: depends on your definition of genetic modification.
這個問題的答案是：取決於如何定義轉基因。
All of the crops that we eat today, wheat, rice and maize, are highly genetically modified from their ancestors,
所有我們今天食用的作物小麥，水稻和玉米與祖先植株相比都是高度轉基因的，
but we don't consider them GM because they're being produced by conventional breeding.
我們不認爲它們是轉基因作物，因爲它們一直是用傳統方式培育的。
If you mean, am I going to put resurrection plant genes into crops, your answer is yes.
如果你問我是不是打算把復甦植物的基因植入作物中，我的回答是是的。
In the essence of time, we have tried that approach.
時間緊迫，我們已經嘗試了這些手段。
More appropriately, some of my collaborators at UCT, Jennifer Thomson, Suhail Rafudeen,
準確地說，我的一些在UCT的同事珍妮弗·湯姆森，薩爾·拉夫德恩，
have spearheaded that approach and I'm going to show you some data soon.
他們已經先行進行了實驗，一會我將展示部分資料。
But we're about to embark upon an extremely ambitious approach,
但是我們將要開展的是一項極具野心的工作，
in which we aim to turn on whole suites of genes that are already present in every crop.
我們的目標是啓動已經存在於每棵植株中的整套基因。
They're just never turned on under extreme drought conditions.
它們只是還沒有在極端乾旱的環境下被激活。
I leave it up to you to decide whether those should be called GM or not.
我希望各位可以自行判斷這種方式是否屬於轉基因。
I'm going to now just give you some of the data from that first approach.
我將展示第一階段實驗的部分資料。
And in order to do that I have to explain a little bit about how genes work.
在展示之前我需要解釋一下基因工作的原理。
So you probably all know that genes are made of double-stranded DNA.
也許大家都知道基因是DNA的雙鏈結構。
It's wound very tightly into chromosomes that are present in every cell of your body or in a plant's body.
它通過緊密的纏繞形成染色體，存在於每個人體或者植物的細胞之中。
If you unwind that DNA, you get genes.
如果把DNA解纏，你就會得到基因。
And each gene has a promoter, which is just an on-off switch, the gene coding region, and then a terminator,
每一個基因有一個啓動子，即是一個開關基因轉錄區和終止子，
which indicates that this is the end of this gene, the next gene will start.
這意味着這一部分基因轉錄結束，下一個基因將要開始轉錄。
Now, promoters are not simple on-off switches.
啓動子不是簡單的開關。
They normally require a lot of fine-tuning, lots of things to be present and correct before that gene is switched on.
它們往往需要大量微調，在基因開關打開之前要進行很多的瞄準和修正過程。
So what's typically done in biotech studies is that we use an inducible promoter, we know how to switch it on.
所以基本上，我們生物技術研究中使用誘導型啓動子來研究如何打開啓動子開關。
We couple that to genes of interest and put that into a plant and see how the plant responds.
我們把它植入我們感興趣的基因，然後把基因植入植株研究植株的反應。
In the study that I'm going to talk to you about, my collaborators used a drought-induced promoter, which we discovered in a resurrection plant.
在我接下來展示的研究中，我的同事使用了在復甦植物中發現的乾旱誘導蛋白啓動子。
The nice thing about this promoter is that we do nothing.
這個啓動子的優勢在於不用外界手段。
The plant itself senses drought.
植物會自發感受乾旱。
And we've used it to drive antioxidant genes from resurrection plants.
我們使用啓動子驅動復甦植物的抗氧化劑基因。
Why antioxidant genes?
爲什麼是抗氧化劑基因？
Well, all stresses, particularly drought stress, results in the formation of free radicals, or reactive oxygen species,
所有的壓力尤其是乾旱的壓力都會形成自由基，也就是活性氧。
which are highly damaging and can cause crop death.
活性氧極具破壞力會直接導致植物死亡。
What antioxidants do is stop that damage.
抗氧化劑可以阻止這種破壞。
So here's some data from a maize strain that's very popularly used in Africa.
這是非洲常用的玉米品種。
To the left of the arrow are plants without the genes, to the right -- plants with the antioxidant genes.
箭頭左邊的是沒有這種基因的，右邊的是含有抗氧化基因的植株。
After three weeks without watering, the ones with the genes do a hell of a lot better.
三週沒有澆水之後，有抗氧化基因的植株的狀態要好得多。
Now to the final approach.
在實驗的最後，
My research has shown that there's considerable similarity in the mechanisms of desiccation tolerance in seeds and resurrection plants.
因爲我的研究已經說明種子和復甦植物的耐旱性的機制有很多相似之處。
So I ask the question, are they using the same genes?
我的問題是他們是同一種基因麼？
Or slightly differently phrased, are resurrection plants using genes evolved in seed desiccation tolerance in their roots and leaves?
還是略有不同地被修飾過？復甦植物是在根部和葉部上也含有這種耐旱基因麼？
Have they retasked these seed genes in roots and leaves of resurrection plants?
在復甦植物中這些基因又被根部和葉部重新使用了麼？
And I answer that question,
我可以回答這個問題，
as a consequence of a lot of research from my group and recent collaborations from a group of Henk Hilhorst in the Netherlands,
通過我和我的同事的小組的工作，通過來自荷蘭的亨克·希爾霍斯特，
Mel Oliver in the United States and Julia Buitink in France.
來自美國的梅爾·奧利弗和來自法國的朱莉婭布克的一系列工作，
The answer is yes, that there is a core set of genes that are involved in both.
我們認爲答案是：是的，它們都有一套完整的核心基因。
And I'm going to illustrate this very crudely for maize,
我會大概以玉米爲例解釋一下，
where the chromosomes below the off switch represent all the genes that are required for desiccation tolerance.
在開關下面的染色體裏面有耐旱性必要的全部基。
So as maize seeds dried out at the end of their period of development, they switch these genes on.
因此當玉米種子在它們發育的最後一個階段面臨乾燥環境時開關就會打開。
Resurrection plants switch on the same genes when they dry out.
復甦植物遇到乾旱環境是也會打開同樣的開關。
All modern crops, therefore, have these genes in their roots and leaves, they just never switch them on.
因此所有現代的植物都在它們的根部和葉部擁有這些基因，只不過它們從來沒有打開過開關。
They only switch them on in seed tissues.
它們只在作爲種子時打開過開關。
So what we're trying to do right now is to understand the environmental and cellular signals that switch on these genes in resurrection plants,
我們現在嘗試要做的就是了解打開復蘇植物基因開關的環境信號和細胞信號，
to mimic the process in crops.
並在作物中模仿類似的過程。
And just a final thought.
最後我想說，
What we're trying to do very rapidly is to repeat what nature did in the evolution of resurrection plants some 10 to 40 million years ago.
我們只是在用飛快的速度重複復甦植物在過去100萬年到400萬年的大自然中進行的進化。
My plants and I thank you for your attention.
我和我的植物感謝您的關注。
