Antioxidant Capacity of Fresh and Dry Leaf Extracts of Sixteen Scutellaria Species

The antioxidant capacity of 16 Scutellaria species was examined using Trolox equivalent antioxidant capacity (TEAC) assay. Total polyphenol, antioxidant capacity estimation and flavonoid content measurements were conducted on fresh and air dried leaf extracts. The highest total polyphenol content was obtained in dry leaf extracts of S. ocmulgee at 732.41 67 mg/g of gallic acid equivalent. Dry leaf extracts of S. ocmulgee registered 2480.93 μmol/g of Trolox equivalent antioxidant capacity and the highest total flavonoid content with 200.63 μg/mL from fresh leaf extracts of S. alpina. Rosemary (Rosmarinus officinalis), a common herb with known high antioxidant potential, was used as a standard for comparison with the Scutellaria species

Transcriptome Analysis of Cambium Tissue of Paulownia Collected during Winter and Spring

Paulownia (Paulownia elongata) is a fast-growing, multipurpose deciduous hardwood species that grows in a wide range of temperatures from –30 °C to 45 °C. Seasonal cues influence the secondary growth of tree stems, including cambial activity, wood chemistry, and transition to latewood formation. In this study, a de novo transcriptome approach was conducted to identify the transcripts expressed in vascular cambial tissue from senescent winter and actively growing spring seasons. An Illumina paired-end sequenced cambial transcriptome generated 297,049,842 clean reads, which finally yielded 61,639 annotated unigenes. Based on non-redundant protein database analyses, Paulownia cambial unigenes shared the highest homology (64.8%) with Erythranthe guttata. KEGG annotation of 35,471 unigenes identified pathways enriched in metabolic activities. Transcriptome-wide DEG analysis showed that 2688 and 7411 genes were upregulated and downregulated, respectively, in spring tissues compared to winter. Interestingly, several transcripts encoding heat shock proteins were upregulated in the spring season. RT-qPCR expression results of fifteen wood-forming candidate genes involved in hemicellulose, cellulose, lignin, auxin, and cytokinin pathways showed that the hemicellulose genes (CSLC4, FUT1, AXY4, GATL1, and IRX19) were significantly upregulated in spring season tissues when compared to winter tissues. In contrast, lignin pathway genes CCR1 and CAD1 were upregulated in winter cambium. Finally, a transcriptome-wide marker analysis identified 11,338 Simple Sequence Repeat (SSRs). The AG/CT dinucleotide repeat predominately represented all SSRs. Altogether, the cambial transcriptomic analysis reported here highlights the molecular events of wood formation during winter and spring. The identification of candidate genes involved in the cambial growth provides a roadmap of wood formation in Paulownia and other trees for the seasonal growth variation

Multiplex knockout of trichome-regulating MYB duplicates in hybrid poplar using a single gRNA.

As the focus for CRISPR/Cas-edited plants moves from proof-of-concept to real-world applications, precise gene manipulation will increasingly require concurrent multiplex editing for polygenic traits. A common approach for editing across multiple sites is to design one guide RNA (gRNA) per target; however, this complicates construct assembly and increases the possibility of off-target mutations. In this study, we utilized one gRNA to target MYB186, a known positive trichome regulator, as well as its paralogs MYB138 and MYB38 at a consensus site for mutagenesis in hybrid poplar (Populus tremula × P. alba INRA 717-1B4). Unexpected duplications of MYB186 and MYB138 resulted in eight alleles for the three targeted genes in the hybrid poplar. Deep sequencing and polymerase chain reaction analyses confirmed editing across all eight targets in nearly all of the resultant glabrous mutants, ranging from small indels to large genomic dropouts, with no off-target activity detected at four potential sites. This highlights the effectiveness of a single gRNA targeting conserved exonic regions for multiplex editing. Additionally, cuticular wax and whole-leaf analyses showed a complete absence of triterpenes in the trichomeless mutants, hinting at a previously undescribed role for the nonglandular trichomes of poplar