Potato Dependency on Nitrogen Fertilizers May Be Reduced by Blocking a Specific Protein
Scientists are searching for methods to alter agricultural plants so they require less nitrogen because nitrogen fertilizers are a contributing factor to global greenhouse gas emissions.
Researchers have discovered that inhibiting a certain protein in potatoes may accomplish this goal, according to a study published in New Phytologist.
Solanum tuberosum CYCLING DOF FACTOR 1 (StCDF1) is a protein that binds to DNA and is essential for controlling potato tuberization. Researchers discovered in this most recent study that StCDF1 regulates the expression of genes associated with nitrogen. In low-nitrogen conditions, plant performance was enhanced by blocking StCDF1.
“Natural variation in StCDF1 binding to the single potato NITRATE REDUCTASE gene emerges as a promising strategy to reduce potato needs of nitrogen fertilizers, as this gene encodes a limiting step for nitrate reduction and later assimilation,” co-corresponding author Salomé Prat, Research Professor, of the Center for Research in Agricultural Genomics, in Spain, mentioned.
Between 2.3% and 2.7% of greenhouse gas emissions worldwide are caused by nitrogen fertilizers. Therefore, maintaining crop output while minimizing the environmental impact of their cultivation is a significant problem of sustainable agriculture. For potatoes to yield large amounts of tubers, nitrogen fertilizer is essential.
Nitrogen deficit leads to early senescence and chlorosis, decreasing tuber size, while the overuse of fertilizers suppresses tuber induction and delays tuber maturity. Uneven nitrogen mineralization due to climate change has been predicted to strongly affect potato production in the coming years.
In this case, through a combination of RNA-seq and DAP-seq studies, the experts provided evidence that StCDF1 not only acts as a canonical repressor of the day-length tuberization pathway but also directly activates a broad group of genes involved in other biological processes. Further, the scientists demonstrate that StCDF1 targets multiple nitrogen transport and assimilation genes, significantly affecting N homeostasis.
“CDFs are clock outputs with a pivotal role in the day length tuberization pathway, while recent studies in Arabidopsis and tomato showed that members of this family modulate response to abiotic stresses, such as heat, cold, drought, or salinity. Here, we confirmed that StCDF1 directly regulates the potato StCOLs, StCDF2, and StCDF3 genes, in addition to binding its promoter and those of the StCDF4 and StCDF5 paralogs. In addition, StCDF1 was observed to directly regulate the StBEL1, StBEL14, and KNOX1/STH20 homeobox genes, earlier shown to be expressed in phloem cells and their RNAs move from leaves to stolons. Importantly, BEL1-like family proteins in association with the POTH1 KNOX1-homolog activate cytokinin biosynthesis and gibberellin catabolism in the stolons, more recent studies also show that this complex regulates SP6A expression. Our DAP-seq studies thus underscore a role of StCDF1 in promoting tuberization beyond StCOLs regulation,” the experts concluded.
