This is good news for cellulosic ethanol/biofuel production.

Could a similar approach be used to make switchgrass and other fast growth perenial plants better feed stocks for cellulosic ethanol/biofuel production?

Not great, corn still uses lots of pesticides and what will you say when this corn makes it into our food supply? Genetic Foods is bad, very bad! We need to stop tinkering with mother nature and start conserving.

It sounds like "RoboCorn" to me ....

These researchers have lost the focus of the goal, which is to not use food crop for Bio-fuels, and instead produced a product for the corn lobby. This is a counter-productive move!

My take:

1. These researchers know a lot about corn, and/or get a lot of funding for corn, so they come up with a "quick, save the corn ethanol tax incentives" angle.

2. So, the vacuoles contain the cellulase enzymes that we're not sure how to manufacture cheaply enough to make cellulosic ethanol affordable (without pyrolisis). Maybe that's good for non-food plants. My concern is that maybe these plants that contain the stuff of their own decay will rot in the field. It's probably manageable, but evolutionarily it is a big disadvantage, and I would think they will be outcompeted by other varieties.

From the article:

"The transgenic corn plants produce these enzymes only in their leaves and stalk, and store them in sub-cellular compartments (the vacuoles)."

This is (stover, not corn) waste to energy cellulosic ethanol. I suppose this initial study was on corn because you-know-who funded it. But now that they've isolated the genes for the appropriate enzymes, the same transgenic technique will work with other plants including say, switchgrass.

They work with corn because they understand corn genetics. No doubt a number of groups are planning on doing this in cane and switchgrass, using different localization within the plant. This is a very sound approach albeit with the genetic engineering safety issues abounding.

What happens if the farmer decides to plow the stover under to improve his soil? (Maybe there's a glut on ethanol, or the genes have escaped into feed corn.)

The cellulose will get broken down into simple sugars in the ground. Pest insects love simple sugars. There will be an infestation of aphids etc, requiring heavy applications of insecticide.

Rather spend the money buying these enzymes from a factory, and leave them out of the crops.

That is a good point. We know from the StarLink corn example that corn pollen drifts on the wind across fields. So much for keeping the genetically modified crops isolated. Then when the farmer wants to use some of that cross pollened corn for seed, the corporations take him to court over patent infringements.

This just sounds like they are putting the enzymes in the corn stalks. I see no need to do this. Pretreatment and enzymes in the factory will do a fine job. It comes down to the phrase that just because they can do it does not mean that they should do it. Good science exercise, but to not deploy this.

The production of ethanol from corn stover does not consume phosphorus or potassium; any of these elements in the stover will be left in the dregs of the fermentation process and can be recycled, either directly or after further processing (use in animal feed, gasification, or some such.)

Why can't they just grow some other plant that does not have such high fertilizer demands, and throw it all in the gasifier and make ethanol with the resulting CO and H2? Is it not economical compared with this complicated ethanol fermentation process?

Nature has produced a plant world that is mostly cellulose because it is much harder for their enemies, mainly bugs, to digest than starches and sugars. Now this team proposes to introduce the enzymes that solve this difficult problem of digestion in none other than the location where it is pre-positioned for digestion already when the crop is in the open field.

I envision that what would happen, sooner or later, with a country covered with these crops is that some bug would hit on a way to take advantage of those enzymes in its stomache and you would have an infestation as sudden and massive as a locust plague. With results comparable to the Irish potato famine, for our alternative energy industry. Likely mother nature would get some help from OPEC's terrorist friends. Farmers would respond with massive application of pesticides.

Seed companies might not see a big problem, since they have all been bought out by chemical companies that make pesticides.

I also suspect that while the researchers are talking up the application of biofuels, which is easier to digest politically, they really have their eye more on making cheap cellulosic crops that can be fed to non-ruminant livestock with little or no processing. Otherwise I don't see what the big attraction is versus the more sensible approach of adding the cellulose-unlocking enzymes in the bioreactor, using microbes like the original cow-derived ones to make the enzymes.

For all that, I can see a positive justification for this research. Because they are pursuing such a dissimilar way of making the enzymes from others, this can be an enzyme manufacturing method of last resort to kick off the biofuels industry in case oil companies bury the patents on all the others. Enzyme-making plants could be grown in sterile greenhouses if necessary. This would help ensure the inevitability of a timely strong biofuels industry. A multipronged alternatives development effort can make it too obvious if obstructionists are closing ranks. You still need a watchdog for this, though.

Harvey D. explained it perfectly. It's sad our elected officials will never understand. We need to conserve and protect our food supply. We are already seeing the effects of rapidly rising food prices around the globe.