Plant genetics: Getting to the root of drought responses

Researchers seeking to develop drought-resistant crops have homed in on ways to keep stomata shut down. It has been difficult to unearth how roots cope with arid conditions. Unlike leaves, their workings are hard to observe. Plant geneticists at the University of Missouri, Columbia, are peering deep inside the roots, at the genes themselves. The group has surveyed gene expression patterns in different parts of maize roots under various stresses and plans to compare them with expression patterns in soy roots. Early analyses suggest that different biochemical pathways underlie drought adaptations in the two species, some of which grow more than others when water is in short supply. Researchers looked at gene activity in a half-dozen of the more diverse responders. Many of the genes were found to be active in the same enzymatic pathways. It seems that many lines had adapted in a similar way, but the activity of different genes in particular pathways changed. They conclude that by crossbreeding lines that show different patterns of gene expression in the same pathway, breeders may come up with hybrids with even better drought tolerance than either of the parent lines.