Can We Bioengineer Crop Plants For A High-CO2 World?

We’re In A Jam

Let’s face it, humanity is NOT going to back off anytime soon on it’s production of greenhouse gases, especially carbon dioxide from the combustion of fossil fuels.

Just last year, for example, atmospheric CO2 emissions increased at their fastest rate for 30 years.

So, how are we to respond to the agricultural challenges posed by the forthcoming high-CO2 (and probably much warmer) world?

Devoting a lot of research time and effort to developing biofuels is probably NOT the answer (see here, for example).

Perhaps a better approach would be to learn as much as we can about how plants respond to high CO2 (and to high temperatures) and to use this basic knowledge in developing the crops of the future.

A paper published in the journal Nature last July (see Ref. 1 below) is a good example of what I’m talking about.

In a previous post I said that elevated levels of CO2 may decrease the ability of many plants to cope with heat stress. But not for the reason that you might think. Here’s a good explanation:

“For each carbon dioxide molecule that is incorporated into plants through photosynthesis, plants lose about 200 hundred molecules of water through their stomata,” explains Julian Schroeder, a professor of biology who headed the research effort. “Because elevated CO2 reduces the density of stomatal pores in leaves, this is, at first sight beneficial for plants as they would lose less water. However, the reduction in the numbers of stomatal pores decreases the ability of plants to cool their leaves during a heat wave via water evaporation. Less evaporation adds to heat stress in plants, which ultimately affects crop yield.” (From: Ref. 2 below)

Scanning electron micrograph of leaf surface featuring stomata.

Scanning electron micrograph of leaf surface featuring stomata.

Simply put, because of this research, we now have a much better understanding of the genes involved in controlling the development of stomata in plants.

What are some of the implications to future crop development of this research?

“The discoveries of these proteins and genes have the potential to address a wide range of critical agricultural problems in the future, including the limited availability of water for crops, the need to increase water use efficiency in lawns as well as crops and concerns among farmers about the impact heat stress will have in their crops as global temperatures and CO2 levels continue to rise.
“At a time where the pressing issues of climate change and inherent agronomic consequences which are mediated by the continuing atmospheric CO2 rise are palpable, these advances could become of interest to crop biologists and climate change modelers,” says Engineer.
(From: Ref. 2 below)

So, can we bioengineer plants for a high-CO2 world?

I think the answer is: YES!

But to do so effectively, we will need lots more basic knowledge about plants, such as that recently provided by the Schroeder research lab at UCSD (Ref. 1 below).

Bottom Line: We are currently spending hundreds of millions of dollars on plant biofuels research. Perhaps this money would be better spent on basic research aimed at understanding (and at preparing for) the effects of high CO2 on plants. (Or better yet, increase funding for basic plant research to levels equivalent to the amount we spend on biofuels research.)

References

1. Engineer, C. B., M. Ghassemian, J. C. Anderson, S. C. Pack, H. Hu, and J. I. Schroeder (2014) “Carbonic anhydrases, EPF2 and a novel protease mediate CO2 control of stomatal development.” Nature, Vol. 513, pp. 246-250. (Abstract)

2. Kim McDonald (2014) “Discovery provides insights on how plants respond to elevated CO2 levels.” Press Release (July 6, 2014), UC San Diego News Center. Full Text

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