The genome of the corn plant - or maize¹, as it's called almost everywhere except the US - "is a lot more exciting" than scientists have previously² believed. So says the lead scientist in a new effort to analyze³ and annotate⁴ the depth of the plant's genetic⁵ resources. "Our new research establishes the amazing diversity of maize, even beyond what we already knew was there," says Doreen Ware⁶, Ph.D., of the US Department of Agriculture and Cold Spring Harbor Laboratory (CSHL) in New York. "This diversity is fascinating in its own right and at the same time has great import for agriculture." Maize is one of the world's top-three staple⁷ foods; along with rice and wheat it accounts for two-thirds of world food consumption.

 

Ware was part of a large multinational⁸ team that in 2009 assembled the first-ever sequence of maize's 30,000 or so genes⁹, based on a single variety called B73. The discovery of maize's extraordinary protein diversity is based on more accurate "long-read" sequencing technology, provided through a research partnership¹⁰ with PacBio, a sequencing company. This updated technology did not reveal very many previously unknown genes, but rather, many more of the RNA messages that are generated when genes are expressed, i.e., activated¹¹.

 

In all, 111,151 RNA transcripts¹² from genes being expressed in six different maize tissues were read and analyzed¹³ in the research. About 57% of these messages had never been seen - and therefore had never been sequenced. "These were the messages that told us that our efforts to annotate and characterize the 2009 maize reference genome have been far from complete," says Bo Wang, Ph.D., a postdoctoral investigator¹⁴ in Ware's lab and first author of the paper reporting the new research.

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