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Genetically Engineered Bananas – Audiommunity with Pamela Ronald

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Bananas are delicious. Personally, my favorite consumption methods are in oatmeal or cereal, in smoothies, or just on their own (for the record, I peel them the right way, not from the stem like some savage). But bananas aren’t just some tasty delicacy, they’re actually a staple crop for millions of people, just behind wheat, rice and corn in terms of importance. Which is why a banana-decimating pathogen has the potential to negatively impact millions of people in East Africa.

So what if you could cross one plant that normally resists the infection with the bananas that these farmers grow? That would be awesome right? Unfortunately, there aren’t any banana varieties that are resistant, they all succumb to infection. But luckily, rice plants do have a resistance gene, and we know what it is. And it turns out, if you put that gene into bananas, they are completely resistant to infection by this banana wilt bacterium.

A few months ago, some colleagues and I started Audiommunity, a podcast about the immune system. Our goal for the podcast and for the website we’re building around it, is to generate an educational resource for people at all levels of education to learn about the immune system, including current, cutting edge research. For the most recent episode, I had the pleasure of interviewing my co-blogger Pamela Ronald, the scientist who first discovered that rice resistance gene (called Xa 21) over 20 years ago, and is now working on making those awesome GMO bananas that could save millions of lives.

On the left, an infected banana plant. On the right, an infected banana that's expressing a gene from rice.

Here on this blog, we know Pam as a great educator when it comes to issues of crop genetics and sustainable agriculture, but it turns out that she’s also an expert on plant immunity. On the podcast, we talk about how she got interested in science, what motivated her to start studying plant immunity, and some of her lab’s recent work on genetically engineering banana plants to express the Xa21 resistance gene. Check it out on, or find “Audiommunity” on itunes.

Kevin Bonham About the Author: Kevin Bonham is a Curriculum Fellow in the Microbiology and Immunobiology department at Harvard Medical school. He received his PhD from Harvard, where he studied how the cells of the immune system detect the presence of infectious microbes. Find him on Google+, Reddit. Follow on Twitter @Kevbonham.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. RobLL 1:18 pm 06/5/2014

    “Unfortunately, there aren’t any banana varieties that are resistant”

    I am curious, do you really mean all varieties, or all commercially and farmed varieties.

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  2. 2. Kevin Bonham in reply to Kevin Bonham 1:45 pm 06/5/2014

    Well, the people that rely most on bananas (and therefore the ones hardest hit by this pathogen) aren’t farming commercially, they’re subsistence farmers. They’re using a lot of different varieties (Pam calls them “backyard banana” strains), but so far no resistant have been found. It’s absolutely possible that there’s something resistant out there somewhere (and difficult to prove a negative), but farmers across East Africa using a lot of different varieties are all being hit by it.

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  3. 3. L_Eplett 5:37 pm 06/5/2014

    Interesting to see this, Kevin and Pam–bananas are a staple crop in Uganda (they’re eaten ripened and unripened when steamed) and I had heard about these problems when I lived there. Look forward to learning more about it!

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  4. 4. be rational 7:32 pm 06/12/2014

    If we get to the point where due to wilt only GMO bananas survive, it will be interesting to see if Whole Foods stops selling bananas.

    And Kevin, if you mean that you eat bananas like a monkey, do you find the peel to be tasty?

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