ABSTRACT
Pinus massoniana needles, rich in medicinal polysaccharides and flavonoids, undergo heteroblastic foliage, transitioning from primary needles (PN) to secondary needles (SN) during growth, resulting in altered functional traits. Despite its significance, the molecular regulatory mechanisms governing these traits remain unclear. This study employs Iso-Seq and RNA-Seq analyses to explore differentially expressed genes (DEGs) associated with functional traits throughout the main growth season of heteroblastic foliage. Co-expression network analysis identified 34 hub genes and 17 key transcription factors (TFs) influencing light-harvesting antenna, photosystem I and II, crucial in photosynthesis regulation. Additionally, 14 genes involved in polysaccharide metabolism pathways, synthesizing sucrose, glucose, UDP sugars, and xylan, along with four genes in flavonoid biosynthesis pathways, regulating p-coumaroyl-CoA, quercetin, galangin, and myricetin production, exhibited differential expression between PN and SN. Further analysis unveils a highly interconnected network among these genes, forming a pivotal cascade of TFs and DEGs. Therefore, heteroblastic changes significantly impact needle functional traits, potentially affecting the pharmacological properties of PN and SN. Thus, these genomic insights into understanding the molecular-level differences of heteroblastic foliage, thereby establishing a foundation for advancements in the pharmaceutical industry related to needle-derived products.
Subject(s)
Pinus , Seedlings , Seedlings/metabolism , Pinus/genetics , Phenotype , Transcription Factors/genetics , Transcription Factors/metabolism , Gene Expression , Gene Expression Regulation, PlantABSTRACT
Fagus longipetiolata Seemen is a deciduous tree of the Fagus genus in Fagaceae, which is endemic to China. In this study, we successfully sequenced the cp genome of F. longipetiolata, compared the cp genomes of the Fagus genus, and reconstructed the phylogeny of Fagaceae. The results showed that the cp genome of F. longipetiolata was 158,350 bp, including a pair of inverted repeat (IRA and IRB) regions with a length of 25,894 bp each, a large single-copy (LSC) region of 87,671 bp, and a small single-copy (SSC) region of 18,891 bp. The genome encoded 131 unique genes, including 81 protein-coding genes, 37 transfer RNA genes (tRNAs), 8 ribosomal RNA genes (rRNAs), and 5 pseudogenes. In addition, 33 codons and 258 simple sequence repeats (SSRs) were identified. The cp genomes of Fagus were relatively conserved, especially the IR regions, which showed the best conservation, and no inversions or rearrangements were found. The five regions with the largest variations were the rps12, rpl32, ccsA, trnW-CCA, and rps3 genes, which spread over in LSC and SSC. The comparison of gene selection pressure indicated that purifying selection was the main selective pattern maintaining important biological functions in Fagus cp genomes. However, the ndhD, rpoA, and ndhF genes of F. longipetiolata were affected by positive selection. Phylogenetic analysis revealed that F. longipetiolata and F. engleriana formed a close relationship, which partially overlapped in their distribution in China. Our analysis of the cp genome of F. longipetiolata would provide important genetic information for further research into the classification, phylogeny and evolution of Fagus.
ABSTRACT
Smilax microphylla C. H. Wright is a climbing shrub that can be used for herbal medicine. The complete chloroplast genome sequence of S. microphylla was determined in this study. It is 158,246 bp in length with a GC content of 37.12%, and consists of a pair of inverted repeat (IR) regions of 27,175 bp, a large single copy (LSC) region of 85,229 bp, and a small single copy (SSC) region of 18,667 bp. The genome encoded 132 genes, including 86 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. The phylogenetic analysis showed that S. microphylla is phylogenetically closely related to Smilax china and Smilax nipponica.
