Can wheat fertilize itself? A study inches closer to that goal.

Self-fertilizing crops are now a step closer to reality: researchers have developed a type of wheat that’s able to capture more nitrogen from the air and transform it into nutrients. Their plants grew larger and stronger under low-nitrogen conditions than conventional wheat. The discovery brings together a specific plant compound with the intriguing world of nitrogen-fixing soil bacteria, also known as diazotrophs. The new study draws on previous research in rice.

In that former work, the scientists discovered that a particular metabolite in rice plants triggers the activity of supportive soil bacteria in the roots around the plant. Based on that clue, they decided to go hunting for something similar in wheat, one of the most-consumed crops in the world with a huge appetite for fertilizer.

From a survey of several thousand compounds in wheat plants, the researchers narrowed it down to a handful that are known to influence the behavior of nitrogen-fixing soil bacteria. From these they selected one most promising candidate: a compound called apigenin that’s involved in several processes in plants. Following their hunch that this compound could also influence soil bacteria, the team used CRISPR gene-tweaking technologies to stimulate the increased production of this compound from wheat plants, which began to produce enough that the excess was released from their roots into the surrounding soil.

Here, the apigenin set an intriguing process in motion: the bacteria use the compound to make these special biofilm coatings around themselves, which in turn provides the perfect, low-oxygen environment in which an enzyme called nitrogenase can function. .IRPP_ruby , .IRPP_ruby .postImageUrl , .IRPP_ruby .centered-text-area {height: auto;position: relative;}.IRPP_ruby , .IRPP_ruby:hover , .IRPP_ruby:visited , .IRPP_ruby:active {border:0!important;}.IRPP_ruby .clearfix:after {content: "";display: table;clear: both;}.IRPP_ruby {display: block;transition: background-color 250ms;webkit-transition: background-color 250ms;width: 100%;opacity: 1;transition: opacity 250ms;webkit-transition: opacity 250ms;background-color: #eaeaea;}.IRPP_ruby:active , .IRPP_ruby:hover {opacity: 1;transition: opacity 250ms;webkit-transition: opacity 250ms;background-color: inherit;}.IRPP_ruby .postImageUrl {background-position: center;background-size: cover;float: left;margin: 0;padding: 0;width: 31.59%;position: absolute;top: 0;bottom: 0;}.IRPP_ruby .centered-text-area {float: right;width: 65.65%;padding:0;margin:0;}.IRPP_ruby .centered-text {display: table;height: 130px;left: 0;top: 0;padding:0;margin:0;padding-top: 20px;padding-bottom: 20px;}.IRPP_ruby .IRPP_ruby-content {display: table-cell;margin: 0;padding: 0 74px 0 0px;position: relative;vertical-align: middle;width: 100%;}.IRPP_ruby .ctaText {border-bottom: 0 solid #fff;color: #0099cc;font-size: 14px;font-weight: bold;letter-spacing: normal;margin: 0;padding: 0;font-family:'Arial';}.IRPP_ruby .postTitle {color: #000000;font-size: 16px;font-weight: 600;letter-spacing: normal;margin: 0;padding: 0;font-family:'Arial';}.IRPP_ruby .ctaButton {background: url(https://www.anthropocenemagazine.org/wp-content/plugins/intelly-related-posts-pro/assets/images/next-arrow.png)no-repeat;background-color: #afb4b6;background-position: center;display: inline-block;height: 100%;width: 54px;margin-left: 10px;position: absolute;bottom:0;right: 0;top: 0;}.IRPP_ruby:after {content: "";display: block;clear: both;}Recommended Reading:How to make low-carbon fertilizer from thin air Nitrogenase is crucial, because this is the ingredient that propels nitrogen fixation from the air, allowing microbes to lock it in and feed it into the plant via the roots.

The more enzyme activity there is, the more nitrogen fixation occurs, and therefore the more nourishment can be supplied to the plant. In fact, experiments on wheat plants proved how effective these amped-up soil bacteria could be. The researchers showed that in a scenario where wheat plants were relatively deprived of nitrogen fertilizer, the plants that had been engineered to produce more apigenin grew more effectively than the conventional wheat plants.

These plants showed increased nitrogen content, photosynthesized more effectively, and produced higher grain yields than the other wheat crops. Seemingly, this was because their root bacteria could supplement low levels of nitrogen in the soil by fixing more nitrogen from the air. Many other strategies to increase wheat yield under low-nitrogen conditions have failed, or not succeeded as well as theirs, the researchers say: they believe their findings represent a real and promising shift.

If their engineered, nitrogen-capturing wheat could be scaled up, it could offer “a sustainable route to reduce dependence on synthetic nitrogen fertilisers,” they say. Blumwald et. “Increased Apigenin in DNA-Edited Hexaploid Wheat Promoted Soil Bacterial Nitrogen Fixation and Improved Grain Yield Under Limiting Nitrogen Fertiliser.” Plant Biotechnology Journal.

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