GM crops created superweed, say scientists (2005) | Hacker News Reader

GM crops created superweed, say scientists (2005)

theguardian.com

58 pointsx5n127 comments

First of all: (2005)

Second of all, super-weeds is a very loaded term, and is a bit mixed up here. What happened is that the gene construct seems to have jumped from Brassica to charlock in a single plant, which wasn't able to produce seed. Contrary to what the article claims charlock is a relatively close relative, being in the same family Brassicaceae. You can even get that from the name - all mustards are Brassicas, and charlock is also called field mustard. The current Latin name for charlock is Sinapis arvensis, but it used to be Brassica arvensis!

What the article mixes up with using the term "superweeds" is that (practically identical with antibiotics in humans) you create new selection pressures for other plants by using herbicides. When you seed GM-plants you can use new herbicides (or use these more indiscriminately) which slowly creates weeds that are resistant, just like we made antibiotics-resistant bacteria in humans. These are now commonly called "superweeds" (again, a very unlucky term). You could leave GM out of the picture and say that these weeds have been created by herbicide (mis-)use.

Since 2005, many more cases of gene flow between GM plants and wild plants have been observed. Are these "bad"? In this case herbicide resistance is not very beneficial to the host plants outside of fields, so these plants are outperformed by others without the modification, as they're wasting resources. Is this bad for the species? Cross-species gene flow happens, and it depends on the case whether it's "good" or "bad".

Actual paper: http://cms.daegu.ac.kr/sgpark/plant%20biotechnology/GMHT%20t...

"When you seed GM-plants you can use new herbicides or use these more indiscriminately" - Hasn't the indiscriminate use of herbicides been linked to causing birth defects in animals and humans [1]?

So if the selection pressure is herbicide resistance, those added newborns with birth defects mean that those without defects are probably also modified.

[1] http://www.laht.com/article.asp?ArticleId=331718&CategoryId=...

There is no link between commonly used herbicides (in the West, I should say) and birth defects.

Your link doesn't where where it was published - but I'd suggest that injecting embryos with herbicide and then claiming any link to reality is ridiculous. You wouldn't even drink herbicides!

I think this is the paper: http://www.gmls.eu/beitraege/113_Carrasco.pdf

There are many links, but no conclusive proof: The long-term effects are unknown, research without commercial funding is slow, and you can not test on humans directly.

Herbicide residues are found in the main foods of the Western diet.

Atrazine is used in Hawaii to test effect. It is the most commonly used herbicide in the US after glyphosate. It is banned in Europe.

"In 2007, the U.S. EPA said, "studies thus far suggest that atrazine is an endocrine disruptor". The implications for children’s health are related to effects during pregnancy and during sexual development, though few studies are available. In people, risks for preterm delivery and intrauterine growth retardation have been associated with exposure. Atrazine exposure has been shown to result in delays or changes in pubertal development in female rats"

Then there is paraquat dichloride. "Paraquat causes fetal losses in high-dose reproductive studies of animals. In studies of Mallard embryos, it causes birth defects."

How do you suggest we remove or strengthen links with research? If injecting embryos with herbicide is not a valid study for birth defects, then what is? Farmers telling us they see lots of disease when switching to herbicides? Simulations? AFAIK, we came to know these herbicides act as endocrine disruptors from embryo research, so is that conclusion ridiculous too?

> (in the West, I should say)

I think the major concern right now is the situation in India. http://www.greenpeace.org/india/en/Press/Glyphosate-based-he... and http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758715/

> You wouldn't even drink herbicides!

Only to commit suicide, which has also been a problem with farmers in India. https://en.wikipedia.org/wiki/Farmers%27_suicides_in_India

'What happened is that the gene construct seems to have jumped from Brassica to charlock in a single plant, which wasn't able to produce seed.'

"The new form of charlock was growing among many others in a field which had been used to grow GM rape. When scientists treated it with lethal herbicide it showed no ill-effects."

Brian Johnson isn't mentioned in the linked to article ..

>You could leave GM out of the picture and say that these weeds have been created by herbicide (mis-)use.

If the point of the genetic modification was to facilitate herbicide (mis-)use, then the genetic modification is a pertinent issue.

who do you work for?

Is this really a surprise to anybody? Create a gene complex which is hugely advantageous, place it in a species well known for horizontal gene transfer, then grow them in an uncontrolled fashion in an environment with huge selection pressure for spreading that gene complex...

This is what really annoys me about GM plants; genetic engineering has the possibility to be so incredibly beneficial, but instead it seems to being used in the most kack-handed way possible. Instead of producing plants that can cope with increased levels of pesticide (this encouraging the use of even more pesticide!), why not produce plants with, e.g., much bigger seed heads? That would give increased crop yield, plus you'd get negative selection pressure for horizontal gene transfer --- the trait would be disadvantageous for weeds and so wouldn't be selected for.

> why not produce plants with, e.g., much bigger seed heads?

How about "Why not produce plants that don't taste like shit?"

The worst thing about living in Berlin (coming from Portugal) is that I can't find tomatoes and other vegetables that have a good taste (or smell).

Why not use GM to make a tomato with a great taste that you can smell from a distance?

One of the first commercially sold GM plants was the "Flavr Savr" (yes that title!) tomato. This tomato used GM tech to reverse some things we humans introduced in the tomato breeding process (lack of taste due to a short ripening process, for example).

It was available in the US (after FDA approval) from 94 to 97. The company went under due to mismanagement and a bit of GM apprehension.

There are many, many more similar projects underway, but nowadays the public apprehension is even bigger, so investors are reluctant to invest in such technology.

> nowadays the public apprehension is even bigger

Really? The mood in the UK feels much more accepting than it did a decade ago.

I have it on good authority (i.e. I heard it on Radio 4) that the enzymes that make tomatoes taste good break down at low temperatures; which means that if you refrigerate your tomatoes they taste painfully bland.

Of course, you have to find tomatoes which haven't been refrigerated anywhere in their supply chain before this becomes worthwhile. But you might want to check out your local farmer's markets.

(Growing up in Britain, I had to go to Cyprus before I realised that tomatoes didn't have to taste like little bland paper bags full of mucus.)

As you have noticed, there are fine tasting tomatoes already, so its likely not a genetic thing, more that they get picked too early.

Creating "much bigger seed heads" is one of those things that sounds much easier than it is. For one, grain crops like wheat have pretty much approached the limit of what's called "harvest index" -- the ratio of the seed head to the rest of the plant in terms of biomass. Any further and the seed head becomes to heavy to support and the plants fall over before harvest.

But more importantly, things like this come down to the difference between qualitative traits(traits like those in Mendel's peas, where a single or a couple genes control the trait and it's inherited in a mendelian fashion) versus quantitative traits(traits controlled by many genes, like skin color in humans, where the distribution of traits within a population takes the form of a bell curve). Glyphosate works by inhibiting the action of a single enzyme, so a single gene coded to produce a variant of the enzyme resistant to the chemical, or an enzyme that can degrade glyphosate, can confer resistance. The yield of a plant and how it distributes its resources however are hugely complex traits that not only involve essentially every gene in the plant in some way, but also environmental factors. It's still simply more effective to use traditional methods, crossing different plants and performing multiple rounds of selection based on yield, than it is to use biotechnology.

Pesticides are the business model.

These crops are being developed by companies like Monsanto, which make and sell the pesticides farmers use. They then turn around and sell the pesticide-resistant corn seed (or wheat seed, or oilseed, or what have you). So you, the farmer, have to buy both the pesticide and the resistant crops every cycle. You're locked into the ecosystem.

Pesticides will be the focus until some agribusiness company finds a more profitable model, or until this model is somehow regulated.

Because addition of a single drug resistant trait is simple and the benefits are immediately observable. There are some experimental GM crop strains aimed at achieving better nutrient levels (golden rice, high lysine maize) or even better, improved photosynthetic efficiency, but these are much harder to commericalise for the lack of a single marketable "gimmick"

>why not produce plants with, e.g., much bigger seed heads? That would give increased crop yield, plus you'd get negative selection pressure for horizontal gene transfer --- the trait would be disadvantageous for weeds and so wouldn't be selected for.

The higher energy requirements make crops more susceptible to weeds, which exacerbates the problem you were trying to solve.

> why not produce plants with, e.g., much bigger seed heads?

The energy to produce the biomass in the seeds still has to come from somewhere, from photosynthesis. They cannot create energy from nothing by just changing a couple of genes. Some people are working on a more energy-efficient version of photosynthesis, but progress has not been fast.

I think we should almost assume by default that anything put out in the environment will spread to other plants. Once we assume that then perhaps we can wield our tools better?

Why would bigger seedheads be disadvantageous for weeds?

Because bigger seedheads cost more. Crops have lots of spare energy, because they're looked after by human farmers. This isn't a problem for them.

It is a problem for weeds --- their energy budgets are already at equilibrium based on their environment. Allocating more of their energy budget to a bigger seedhead means less energy for doing other things, which would put them at a disadvantage.

As an example, look how badly most of our engineered crops do in the wild; there's massive selection pressure against the engineering that makes them useful to us.

Be interesting to see how this plays out with the "Anti-GM is irrational anti-science woo" brigade.

Yes - genetic modification is not doing anything that couldn't happen by normal mutation/selection - but it accelerates the process by multiple orders of magnitude (that's the whole point).

Making the debate one of 'show us evidence of harm or shut up' always felt fairly short-sighted.

I always felt that there is a huge 'unintended consequences' factor lurking somewhere. The need for a deep sense of caution when working on a new frontier struck me as more rational than a stance that basically boiled down to "let's assume we haven't overlooked any potential risks".

> The need for a deep sense of caution when working on a new frontier struck me as more rational than a stance that basically boiled down to "let's assume we haven't overlooked any potential risks".

It's an economically profitable assumption for the particular businesses which happen to operate with it. Especially when they are able to lobby congress to encourage this point of view.

> Yes - genetic modification is not doing anything that couldn't happen by normal mutation/selection

Transgenic GM crops have genes inserted into them from viruses and bacteria.

https://en.m.wikipedia.org/wiki/Horizontal_gene_transfer

Awesome news. Hopefully it will render herbicides useless.

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