Plant geneticists demonstrate new means of boosting maize yields


A team of plant geneticists at Cold Spring Harbor Laboratory (CSHL) has successfully demonstrated what it describes as a "simple hypothesis" for making significant increases in yields for the maize plant.

Called corn by most people in North America, modern variants of the Zea mays plant are among the indispensable that feed billions of the planet's people. As soars beyond 6 billion and heads for an estimated 8 to 9 billion by mid-century, efforts to boost yields of essential food crops takes on ever greater potential significance.

The new findings obtained by CSHL Professor David Jackson and colleagues, published online today in , represent the culmination of over a decade of research and creative thinking on how to perform genetic manipulations in maize that will have the effect of increasing the number of its seeds – which most of us call kernels.

Plant growth and development depend on structures called meristems – reservoirs in that consist of the plant version of stem cells. When prompted by genetic signals, cells in the meristem develop into the plant's organs – leaves and flowers, for instance. Jackson's team has taken an interest in how quantitative variation in the pathways that regulate plant contribute to a plant's growth and yield.

"Our simple hypothesis was that an increase in the size of the meristem – the stem-cell reservoir that gives rise to flowers and ultimately, after pollination, seeds – will provide more physical space for the development of the structures that mature into kernels."

Dr. Peter Bommert, a former postdoctoral fellow in the Jackson lab, performed an analytical technique on several maize variants that revealed what scientists call quantitative trait loci (QTLs): places along the chromosomes that "map" to specific complex traits such as yield. The analysis pointed to a gene that Jackson has been interested in since 2001, when he was first to clone it: a maize gene called FASCIATED EAR2 (FEA2).

Not long after cloning the gene, Jackson had a group of gifted Long Island high school students, part of a program called Partners for the Future, perform an analysis of literally thousands of maize ears. Their task was to meticulously count the number of rows of kernels on each ear. It was part of a research project that won the youths honors in the Intel Science competition. Jackson, meantime, gained important data that now has come to full fruition.

The lab's current research has now shown that by producing a weaker-than-normal version of the FEA2 gene – one whose protein is mutated but still partly functional—it is possible, as Jackson postulated, to increase meristem size, and in so doing, get a to produce ears with more rows and more kernels.

How many more? In two different crops of maize variants that the Jackson team grew in two locations with weakened versions of FEA2, the average ear had 18 to 20 rows and up to 289 kernels – as compared with wild-type versions of the same varieties, with 14 to 16 rows and 256 kernels. Compared with the latter figure, the successful FEA2 mutants had a kernel yield increase of some 13%.

"We were excited to note this increase was accomplished without reducing the length of the ears or causing fasciation – a deformation that tends to flatten the ears," Jackson says. Both of those characteristics, which can sharply lower yield, are prominent when FEA2 is completely missing, as the team's experiments also demonstrated.

Teosinte, the humble wild weed that Mesoamericans began to modify about 7000 years ago, beginning a process that resulted in the domestication of maize, makes only 2 rows of kernels; elite modern varieties of the plant can produce as many as 20.

A next step in the research is to cross-breed the "weak" FEA2 gene variant, or allele, associated with higher kernel yield with the best lines used in today's food crops to ask if it will produce a higher-yield plant.

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More information: "Quantitative variation in maize kernel row number is controlled by the FASCIATED EAR2 locus" appears online in Nature Genetics on February 3, 2013.
Journal information: Nature Genetics

Citation: Plant geneticists demonstrate new means of boosting maize yields (2013, February 3) retrieved 24 August 2019 from
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Feb 03, 2013
Would it not be more efficient to increase the number of ears per stalk to 5 (next Fibonocci number) instead of 3?

Feb 03, 2013
More ears means more stalk. Each plant can only grow so much total biomass. increasing the size of each ear is much more efficient than adding new ears.

Feb 04, 2013
Edit: Delete -- never mind, decided against feeding the troll.

Feb 04, 2013
Malthus the saint curses you all, all eight billion of you, humans.

Feb 04, 2013
I like this article because they correctly identify the plant as Maize.

Feb 04, 2013
Maybe one day we will simply grow kernels in a solution or on a substrate like a sponge in a couple of weeks in stead of waiting months for a whole plant to grow. We can grow animal eggs and sperm from stem cells in a lab, so why not do the same with plant seeds?

Now THAT would be a huge deal. No more cultivation, fertilization, irrigation, pesticides, harvesting or transportation (you would grow it where you're gonna process it).

Same goes for other food products. Perhaps one day we will just grow muscle tissue in stead of raising whole cows, pigs and fish.

Mar 26, 2013
The funniest thing is that a big part of the population they claim to feed doesn't actually eat corn (though they do eat meat, I agree).
I admit I didn't even read the whole article. I just can't buy that all "glorious progress on feeding the hungry" tone. The facts are that there is GM corn for quite long time now. And there is NO progress on feeding the hungry what's-o-ever. The moneyless are simply not the target group for such production. On the other side, rare diseases and cancer are getting more and more often. It is not hard to see why some people just hate GMO products.
I mean what do I care, that a farmer would produce more corn with less investments, when I buy the food on the same price and what I or anyone don't BUY, just gets thrown out or burnt, instead of fed to the poor. If I am to buy something, it would be organic, thank you very much!

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