Functional Characterization of GmRD22 Modulating Nitrogenase Activity in Soybean with Transcriptomic Comparison Between Two Genotypes

The carbon-nitrogen metabolism gene E1OGDH1 influences maize root system architecture and nitrogen plasticity

Synthetic nitrogen fertilizers have greatly increased crop yields, yet much of the applied nitrogen is lost from agroecosystems and contributes to environmental pollution and higher economic costs. Improving nitrogen uptake efficiency (NUpE) benefits from understanding how root system architecture (RSA) governs soil nitrogen capture. Although root traits have seldom been explicit breeding targets, selection for variation in above-ground nitrogen accumulation has also likely shaped differences in RSA. The Illinois Protein Strain Recombinant Inbred population, derived from more than a century of divergent selection for seed protein concentration, offers a powerful resource for dissecting RSA variation. Using multi-year field phenotyping of excavated root crowns and genome-wide association analysis, we identified a quantitative trait locus on chromosome 10 containing E1OGDH1, which encodes the E1 subunit of the 2-oxoglutarate dehydrogenase (OGDH) complex. OGDH performs a key step in the tricarboxylic acid cycle that also modulates 2-oxoglutarate, an important entry point into nitrogen metabolism and a co-factor for enzymes involved in hormone and secondary product synthesis. Long-read sequencing of inbreds derived from the divergent IHP and ILP parental populations revealed promoter polymorphisms defining E1OGDH1 alleles and differed in E1OGDH1 expression in root tissue. Field experiments in IPSRI lines carrying IHP- or ILP-associated E1OGDH1 alleles showed differences in root architectural traits over two years. CRISPR-Cas9 knockout mutants confirmed a functional role for E1OGDH1 in whole-plant performance and nitrogen-responsive root development. Mutants were shorter, had reduced biomass, and exhibited altered architectural responses to soil nitrogen levels. Transcriptome analysis further showed that loss of E1OGDH1 altered basal and nitrogen-responsive expression of genes associated with root development and nitrogen uptake and metabolism. Together, these findings identify E1OGDH1 as a strong candidate quantitative regulator of maize RSA and nitrogen plasticity, suggesting that central carbon–nitrogen metabolic genes can contribute to root developmental responses relevant to NUpE.

The COBRA-Like9 from Glycine tabacina enhanced salt tolerance in cultivated soybean

Unveiling GmCS1 Promote Branch Development by Regulating Plant Hormones in Soybean

Soybean (Glycine max (L.) Merr.) was originally domesticated in China and is a kind of significant leguminous crop, which can fix atmospheric nitrogen to bioavailable nitrogen in association with rhizobia. Ceramides, intermediates of sphingolipids, are crucial structural components in membrane formation and also function as signaling molecules, which play crucial roles in plant development and defense. Although Arabidopsis ceramide synthase genes AtLOH1 and AtLOH3 overexpression plants increased biomass compared to the wild type, the potential mechanism in plant growth was still unclear. A soybean ceramide synthase gene 1 (GmCS1) has a high expression level in the stem, and the protein is localized in the endoplasmic reticulum. Overexpression of GmCS1 promotes soybean lateral branch development for effective branch formation, significantly increasing the number of lateral branches and pods. Using transcriptomic profiles, we found that GmCS1 overexpression lines displayed the upregulation of plant hormone signal transduction pathway gene expression in developmental branches. Actually, Indole-3-acetic acid (IAA) induces bud outgrowth rather than initiation according to the determination of endogenous IAA and cytokinin (CKs) in soybean lateral branches. Collectively, these results suggest that GmCS1 may be a functional ceramide synthase gene in soybean, with the GmCS1-mediated regulatory network playing a crucial role in controlling branch development by IAA and CKs homeostasis. Exploring the regulation mechanisms by GmCS1 overexpression lines is essential for Ideal Soybean Architecture (ISA) innovation.

Allelic Diversity of Candidate Genes Underlying Nitrogen Use Efficiency in Potato

Potato is a globally important food crop, but its production faces major challenges related to inefficient nitrogen fertilizer use. Excessive nitrogen application, particularly in intensive agricultural systems, compromises sustainability and increases environmental and health risks. Improving nitrogen use efficiency (NUE), defined as the capacity of plants for nitrogen uptake and assimilation, is therefore essential to optimize fertilization practices and enhance sustainable crop production. In this study, we analyzed candidate genes associated with NUE in a diploid potato diversity panel (Solanum tuberosum Group Phureja) by evaluating morphological, physiological, and biochemical variables under contrasting nitrogen levels. Association analyses were performed between these variables and genetic polymorphisms within NUE-related genes. Single nucleotide polymorphisms (SNPs) were identified in three candidate genes: AMT1.1 (ammonium transporter), 2OGDD (2-oxoglutarate-dependent dioxygenase), and PPR (pentatricopeptide repeat protein gene). These variants explained 8–20% of the phenotypic variation in traits such as relative chlorophyll content, aerial biomass, and NUE. Notably, a missense variant (Lys → Glu) in 2OGDD was associated with a 30.5% reduction in NUE under low nitrogen conditions, suggesting distinct adaptive strategies. Specific SNPs were associated with NUE-related traits, representing candidate variants for future functional validation and marker-assisted breeding.

Integrated Transcriptomic and Phenotypic Analyses Reveal Tissue-Specific Nitrogen Responses and Candidate Genes for Low-Nitrogen Tolerance in Sorghum

The A allele (Hap1) was significantly associated with increased plant height, SPAD value, grain number, nitrogen accumulation, nitrogen accumulation, and biomass under LN stress, suggesting that SORBI_3001G116400 as a candidate gene requiring functional validation and testing in additional genetic backgrounds.

Genome-wide Identification of CXE Gene Family in Soybean and Functional Characterization of GmCXE31 in Lipid Biosynthesis and Salt Tolerance.

This study elucidates the multifaceted roles of GmCXE31 in coordinating soybean salt tolerance, lipid metabolism and agronomic traits, providing theoretical and genetic resources for salt-tolerant and high-quality soybean molecular breeding.