Its pretty tempting to say that a carrot being chopped, diced, then boiled, sauteed or just eaten alive, would be morally wrong. But there are pretty clear relevant differences between plants and animals, the biggest being that animals are conscious, plants are not. The burden of proof are on the defenders of vegetables that plants are conscious, not on me to show you that they are not. But if you insist, consciousness as we know it, requires at the very least a central nervous system e.g. brain, that they lack completely. Show me a plant with a brain, and then perhaps we can discuss the rights of the veggie.
BUT.... Switzerland has recently built it into their constitution that the moral status of plants must be considered. So what is an ethicist to say about the moral status of plants?
In April, the team published a 22-page treatise on "the moral consideration of plants for their own sake." It stated that vegetation has an inherent value and that it is immoral to arbitrarily harm plants by, say, "decapitation of wildflowers at the roadside without rational reason."
There are a couple of points here that we need to parse out here. First: vegetarion has inherent value. I'm not sure that it does. Life for life's sake isn't particularly compelling to me, otherwise I would be happy when I find weeds in my lawn. There's more vegetation! I remember listening to the Ig Nobel awards (A satirical awards show that gives awards for the strangest research) last year, and hearing about the paper for the first time. The recipient of the award said that if you ever had a house plant and felt bad about it dying, then you understand the inherent value of vegetation. But I don't think I feel bad because of the plant's death, I feel bad because I've lost the aesthetic value of the plant, and its been replaced with something that creates ugliness.
I do find that it is wrong to arbitraily harm plants... But not because of an inherent value in plants, but because of the environmental impact (however small) that it will have. If its a small impact, then the wrongness may be only a small one, that can be overlooked. But done at a massive scale, the wrongness scales exponentially. (Sheesh I really am a consequentialist arn't I?)
All of this is for a point however. Switzerland doesn't want genetically modifiied crops in their country. If GM crops are created, and typically they are created infertile so they can't spread their genetically modifiedness (its a word.... now.) around to other crops. But if plants have dignity, then it would be wrong to deprive them from reproduction.
This is all dancing around the notion of the sanctity of life. Tampering with life is wrong, strong period. But this notion is pretty archaic in today's society. We tamper with ourselves, just as much as we tamper with other beings, be it plastic surgery, cybornetic implants, or flu shots, we tamper with the way we function, and the way we are. Peter Singer has a pretty good book that gets to the heart of this issue (unsanctifying human life).
If consequentialism gives us some reasons for protecting kinds of life from harm and not others, does that mean that some animals could conceivably be harmed just like plants? Sure. In fact, I'm not terribly sure I can muster a strong defense for keeping Panda Bears around on the planet beyond that they please humans aesthetically.... but ultimately that may be enough for a consequentialist. If Pandas were to mutate into a non-aesthetic beast of a creature that did nothing but eat bamboo, and had no predators and no other ecological niche to fill, then extinction wouldn't be a loss at all.