Nutritionists like to recommend people to take a balanced diet to stay healthy. This seems a simple task at a first glance, but it could be really hard to stick for long. However, this could be indeed a simple task for plants. Because plants are sort of born nutritionists, having a knack for balanced diets. They are equipped with built-in sensors and signaling networks that together enable the plant host to monitor soil nutrients in real time and uptake those in a balanced manner to suffice optimal growth and yield.
In a recent study published in Nature Plants (doi: 10.1038/s41477-019-0384-1), scientists from the CAS Institute of Genetics and Developmental Biology found that NRT1.1B, a nitrate sensor in rice (Oryza sativa L.), also controls the uptake of phosphate from the soil to achieve a coordinated nutrient utilization. The study shows that nitrate perception strengthens the binding of NRT1.1B with SPX4, a phosphate signaling repressor that acts to inhibit the utilization of phosphate. The enhanced binding promotes the degradation of SPX4, and subsequently activates the phosphate-responsive genes that act to improve phosphate utilization. Interestingly, many nitrate-responsive genes are also under the control of SPX4. So, these two nutrient signaling pathways are intertwined and coordinated.
“This work represents a breakthrough in the field of nutrient signaling and beyond regarding the novel and highly intertwined organization of these two nutrient signaling pathways,” highlighted by a commentary in the same issue of Nature Plants, “it also raises an exciting question: how often is this mode of coordination happens in other signaling pathways?”
This signaling coordination explains for how plants uptake different nutrients in a balanced way, which may find use in creating the smart crops for a more sustainable agriculture. After all, the crops would feed the world better if the soil feed them more properly at the first place.
(By YAN Fusheng)