Apple Gene for Red Color Found

FiReaNGeL writes "Researchers have located the gene that controls the red color of apples — a discovery that may lead to bright new apple varieties. 'The red color in apple skin is the result of anthocyanins, the natural plant compounds responsible for blue and red colours in many flowers and fruits,' says the leader of the CSIRO. By identifying master genes that were activated by light, they were able to pinpoint the gene that controls the formation of anthocyanins in apples. 'As well as giving apples their rosy red hue, anthocyanins are also antioxidants with healthy attributes, giving us plenty of reasons to study how the biochemical pathway leading to apple color is regulated,' researchers said."

Bright new apple varieties?

[bill_mcgonigle]

bright new apple varieties.

Maybe not. There was just a nobel prize awarded in this area of research. IIRC, the gene expression is regulated by a twisted helix RNA type which prevents overexpression of given genes, and there's some feedback mechanism which causes the chromosomal DNA to stop expressing the mRNA after a while.

The original studies which started this were botanists trying to make more pink petunias - when they inserted more "pink" genes, the petunias came out white. The prize research was about regulation in c.elegans.

Botanists and molecular biologists will now shred my analysis. :)

It's the genetics not the color or the chemicals

[scattol]

Apples taste is chiefly controled by their genetics. Essentially, watery and tart apples tend to be early summer apples and crips and sweet ones are late fall varieties. There is, essentially an direct correlation/tradeoff with maturing time and taste. Everything else that the farmer does only affect this a tiny bit. Otherwise they could turn their Melbas into Cortland just by spraying them which simply doesn't happen.

The weather that year also plays an important role, mainly rainfall and the amount of sun and heat. That's easily demonstrated as the main factor by the simple fact that all the farmers in a region get the same kind of results for a given year (small red apples, big lightly colored ones, fragile things that fall on the ground).

In fact chemicals are very expensive to an apple grower so you can bet that they try to use them as little as they can.

That's not to say that they don't spray, they do spray a lot but it's in their best interest to spray as little as possible and many are trying to limit their use of chemicals.

If there is anything wrong, it's the association in consumer's mind of the red color and ripeness. You can have perfectly sweet and ripe fruits but that aren't all that red. This has lead to variety (like the delicious) that is very red but has no taste. To each his own.

Re:Bright new apple varieties?

[jcmurray]

I'm not an "ordained" molecular biologist, but I'll add to your comments. Bright new apple varieties can be introduced into apples via genetic manipulation at the chromosomal (genomic) DNA level. In organisms, from plants to animals, you can inject (or "transfect") a specific gene into a cell relatively easily. This type of injection can be permanent or temporary. A permanent injection could yield a new apple variety. This is direct genetic manipulation.

There is another way. The tried-and-true method for introducing new apple varieties would involve mating (or "crossing") current apple varieties which represent traits of interest. For example, find the two shinest, reddiest apples and cross them to see if you can generate an even shiner, redder apple. This is indirect genetic manipulation, which relies upon specific selection.

Finally, yes, there was a Nobel Prize awarded for the discovery of a mechanism for gene silencing called RNA interference, or RNAi. Scientists tried injecting double stranded RNA (dsRNA) encoding "pink" genes into petunias. This RNA interfered with the normal expression of the pink genes, which yielded white plants. This mechanism, RNAi, is now used to limit (or "knockdown") the expression of specific genes in labs around the world. It is a powerful and useful technique. To clarify, the chromosomal DNA doesn't actually stop expressing the gene--it still makes messanger RNA ("mRNA") for the gene, but does not translate the mRNA into protein. These mRNAs are effectively blocked or degraded before translation via RNAi, as long as the RNAi components are present in the cell. To permanently block the expression of a gene via RNAi, one must use the method of transfection (described above) to insert the RNAi "gene" into chromosomal DNA.

Hope this helps. (I tend to be a bit long-winded.)

Re:It's the genetics not the color or the chemical

[Anonymous Coward]

Thats a result of differing UK/US terminoligy. In the UK we refer to the alcoholic drink made from apples as "cider" but in the US "cider" referes to cloudy pressed apple juice and the alcoholic drink is called "hard cider"

Re:Apple Knowledge

[Zontar_Thing_From_Ve]

participated in an apple tasting festival a year or so ago, and I only really learned one thing. The uglier the variety of apple, the better it tastes. A perfectly-colored, gargantuan Red Delicious from the store has nearly no flavor whatsoever. By contrast, if you find one that looks like a potato, you are in for a treat.

In fact, studies have shown that the redder the apple, the worse it tastes. This along with a decision by growers to select cultivars for appearance and not taste is why Red Delicious is certainly not delicious but more often than not mush when you taste it. I'm a little skeptical that increasing the amount of anthocyanins in apples is a good idea because I think those tend to be bitter in taste and bitterness is not a desirable characteristic of apples.