WHEAT WAS among the many first crops to be domesticated and is now probably the most widespread crop on the planet. It thus sounds unlikely there can be a lot left to study what makes it thrive. But, some 12,000 years after relations between individuals and wheat started, a wheat plant has been caught doing one thing sudden. It helped itself to a dose of much-needed phosphorus when its leaves acquired a coating of desert mud.
The plant (or, moderately, crops) in query had been within the care of Avner Gross of the Ben Gurion College of the Negev, in Israel. As Dr Gross instructed this 12 months’s assembly of the American Geophysical Union, which passed off on-line through the first half of December, his research was prompted by hikes he had taken close to Neve Shalom, his residence village within the Judean Hills. On these, he usually observed plant leaves fully lined in mud that had been carried there by sand storms from the Sahara desert.
It occurred to him that this mud may not be the light-blocking nuisance it appeared at first sight. It may, quite the opposite, be helpful due to the growth-enhancing components corresponding to phosphorus which it contained. Till then, botanists had assumed that phosphorus in mud touchdown on a plant was of little worth, as a result of it’s locked up in an insoluble mineral referred to as apatite. This makes it unavailable for absorption. Dr Gross, nonetheless, reasoned that crops which had developed close to deserts, the supply of virtually all naturally occurring mud within the environment, would possibly properly have developed a approach to exploit it.
He and two colleagues, Sudeep Tiwari, additionally at Ben Gurion, and Ran Erel of the Gilat Analysis Centre, subsequently began experimenting with a pair of species, wheat and chickpeas (the world’s seventeenth most planted crop), that each got here initially from the Center East. As a management, additionally they raised some maize, a plant from the Americas that developed in far much less dusty environment.
First, having established them as seedlings, they starved their costs of phosphorus till indicators of deficiency corresponding to yellow leaves appeared. Then they scattered desert mud on the leaves of half of the specimens of every species, whereas taking steps to cease any of it reaching the soil. After this, although the dust-dosed maize continued to undergo from phosphorus deficiency, the wheat and chickpea crops perked up and grew to greater than double the scale of their undusted lab-mates. What’s extra, these species had been clearly prepared for the mud’s arrival. As quickly as an absence of phosphorus introduced itself, two issues occurred. Their leaves turned hairier, and subsequently higher at capturing mud. And people leaves additionally began secreting acid fluids that might dissolve any incoming apatite, helping phosphorus’s absorption.
That crops can take up phosphorus by means of their leaves will not be, of itself, information to farmers—for this was established within the Fifties. However till now the sensible consequence of such data has been that crops are sprayed with liquid fertiliser derived, in flip, from apatite-containing rocks which have been handled with acid. Dusting leaves may, Dr Gross suggests, be another and extra environment friendly manner of offering desert-derived crop species with the phosphorus they want. And possibly not simply these. His subsequent plan is to take a look at avocado and cocoa bushes, which developed in tropical areas of the Americas that commonly get a useful transatlantic dose of Saharan mud carried westward by the commerce winds. It will likely be attention-grabbing to see if they’re as much as the identical tips as wheat and chickpeas.■
This text appeared within the Science & know-how part of the print version beneath the headline “Good catch”