Integrative Dissection of Lignin Composition in Tartary Buckwheat Seed Hulls for Enhanced Dehulling Efficiency.

The rigid hull encasing Tartary buckwheat seeds necessitates a laborious dehulling process before flour milling, resulting in considerable nutrient loss. Investigation of lignin composition is pivotal in understanding the structural properties of tartary buckwheat seeds hulls, as lignin is key determinant of rigidity in plant cell walls, thus directly impacting the dehulling process. Here, the lignin composition of seed hulls from 274 Tartary buckwheat accessions is analyzed, unveiling a unique lignin chemotype primarily consisting of G lignin, a common feature in gymnosperms. Furthermore, the hardness of the seed hull showed a strong negative correlation with the S lignin content. Genome-wide detection of selective sweeps uncovered that genes governing the biosynthesis of S lignin, specifically two caffeic acid O-methyltransferases (COMTs) and one ferulate 5-hydroxylases, are selected during domestication. This likely contributed to the increased S lignin content and decreased hardness of seed hulls from more domesticated varieties. Genome-wide association studies identified robust associations between FtCOMT1 and the accumulation of S lignin in seed hull. Transgenic Arabidopsis comt1 plants expressing FtCOMT1 successfully reinstated S lignin content, confirming its conserved function across plant species. These findings provide valuable metabolic and genetic insights for the potential redesign of Tartary buckwheat seed hulls.

VAMP726 from maize and Arabidopsis confers pollen resistance to heat and UV radiation by influencing lignin content of sporopollenin.

Sporopollenin in the pollen cell wall protects male gametophytes from stresses. Phenylpropanoid derivatives, including guaiacyl (G) lignin units, are known to be structural components of sporopollenin, but the exact composition of sporopollenin remains to be fully resolved. We analyzed the phenylpropanoid derivatives in sporopollenin from maize and Arabidopsis by thioacidolysis coupled with nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). The NMR and GC-MS results confirmed the presence of p-hydroxyphenyl (H), G, and syringyl (S) lignin units in sporopollenin from maize and Arabidopsis. Strikingly, H units account for the majority of lignin monomers in sporopollenin from these species. We next performed a genome-wide association study to explore the genetic basis of maize sporopollenin composition and identified a vesicle-associated membrane protein (ZmVAMP726) that is strongly associated with lignin monomer composition of maize sporopollenin. Genetic manipulation of VAMP726 affected not only lignin monomer composition in sporopollenin but also pollen resistance to heat and UV radiation in maize and Arabidopsis, indicating that VAMP726 is functionally conserved in monocot and dicot plants. Our work provides new insight into the lignin monomers that serve as structural components of sporopollenin and characterizes VAMP726, which affects sporopollenin composition and stress resistance in pollen.

Associations between periodontal diseases and systemic diseases: a review of the inter-relationships and interactions with diabetes, respiratory diseases, cardiovascular diseases and osteoporosis.

The aim of this review article is to examine the associations between periodontal diseases and common systemic diseases, namely diabetes, respiratory diseases, cardiovascular diseases and osteoporosis. A substantial number of review articles have been published to elucidate the relationships between these diseases; however, none provide a complete overview on this topic from the aspects of definition, classification, clinical characteristics and manifestations, inter-relationships and interactions, proposed schematic mechanisms, clinical implications and management of periodontal patients with these systemic diseases. The aim of this article is to provide an overall understanding and general concepts of these issues in a concise and inter-related manner.

An in vivo study of a bone grafting material consisting of hydroxyapatite and reconstituted collagen.

This study aims to evaluate the performance of our recently developed microspheres of hydroxyapatite/reconstituted collagen as a bone grafting material. The microspheres were fabricated into a circular disc and implanted in a pre-drilled hole in a rat's calvaria. The bone tissue had regenerated and grown into the disc bone graft 4 weeks following implantation. After 16 weeks of implantation, the regenerated bone had integrated with the remaining material and made close contact with it. The disc had been completely absorbed with almost no visible bone graft left after 24 weeks of implantation. In contrast, a hydroxyapatite disc still remained intact on the 24th week after implantation. These results suggested that the hydroxyapatite/reconstituted collagen microsphere can be used as an excellent bone grafting material.