Results for “Carboxy-Lyases”

PubMed2026

Genome-wide identification of CXE gene family in soybean and functional characterization of GmCXE31 in lipid biosynthesis and salt tolerance.

GmCXE31 negatively regulates salt tolerance and lipid synthesis in soybean, and the cxe31-edited lines improve soybean yield and seed quality. Carboxylesterases (CXEs), as essential lipid hydrolases of the α/β-hydrolase fold superfamily, are critical for plant stress responses, hormone signaling and secondary metabolism. The key candidate gene GmCXE31 was previously identified in our laboratory through a genome‑wide association study (GWAS) of soybean lipid‑related traits. In the present study, we further identified 60 GmCXE family genes in soybean. Phylogenetic analysis clustered them into 11 conserved subfamilies. Cis-acting element analysis showed their promoters are enriched with elements related to abiotic stress, growth and hormone signaling, suggesting potential roles in soybean development and stress adaptation. GmCXE31 is highly expressed in seedling roots and responsive to strigolactones (SLs) and salt stress. Functional assays revealed that GmCXE31 negatively regulates soybean salt tolerance: its overexpression reduced salt tolerance in Arabidopsis and soybean under 150 mM NaCl stress, while its knockout enhanced this trait. Lipid profiling revealed GmCXE31-edited lines had higher seed oil content, elevated oleic/linoleic acid ratio and lower saturated fatty acid proportion, which was achieved by regulating lipid synthesis-related genes like GmNFYA. Agronomic trait analysis showed GmCXE31-edited lines had increased nodule number, plant height and single-plant yield at maturity, with opposite phenotypes in overexpression lines. In conclusion, 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.

Glycine max↗

PubMed2026

Addressing lignin composition and content via Arabidopsis arogenate dehydratase knockout and over-expression genotypes.

Following the down-selection of 14 Arabidopsis thaliana arogenate dehydratase (ADT) knockout and over-expression (OE) genotypes, the most highly contrasting quadruple knockout adt3/4/5/6 and ADT OE genotypes were subjected to proteomics, metabolomics, and scanning electron microscopy (SEM) analyses as needed, with results compared to Columbia wild-type (WT). The basal adt3/4/5/6 stem cross-sections, ∼70% lignin content reduced, exhibited buckled vessel cell walls and partially detached xylary fibers, in contrast to WT and ADT4m/5 m OE genotypes that did not. Anatomical defects primarily resulted from guaiacyl lignin level reductions in vessels with concomitant increased stem syringyl:guaiacyl (S/G) ratios. Phenylpropanoid and various upstream shikimate-chorismate pathway enzyme abundances, as well as specific monolignol oxidases (laccases/peroxidases), generally increased in adt3/4/5/6 at different stem and rosette leaf growth/development stages, relative to WT. Opposite effects were largely observed with the ADT5m OE genotype. By contrast, flavonoid and glucosinolate pathway enzyme amounts varied. Such enzyme abundance increases were overall unproductive as adt3/4/5/6 was unable to restore WT, ADT4 OE, ADT5 OE, ADT5m OE, and ADT4m/5 m OE secondary metabolite (lignin, phenylpropanoid, lignan, flavonoid, phenolic acid, and glucosinolate) levels. Conversely, ADT OE genotypes did not significantly increase programmed lignin levels or alter S/G compositions. In sum, proteomics analyses of adt3/4/5/6 and adt5 'perceived' that lignin and low molecular weight secondary metabolite amounts were not at 'programmed' levels as for WT and ADT OE genotypes but observed increases in relevant pathway protein abundances were futile. Notably though, proteomics analyses did not lead to predicting that lignin and associated biochemical pathways would have reduced metabolite levels, relative to WT and ADT OE genotypes. Genotype adt3/4/5/6, possibly the highest lignin level reduced genotype reported, did not utilize other phenolics to compensate. By contrast, the differential temporal and spatial deposition of cell wall oxidases again indicate the exquisite control over lignin deposition, and our lack of knowledge of precise lignin structure and assembly in subcellular regions of the lignified cell walls.

Lignin↗