Transcriptomic Analysis of Green Leaf Plants and White-Green Leaf Mutants in Haworthia cooperi var. pilifera.

Haworthia cooperi var. pilifera is a succulent plant with ornamental value. The white-green leaf mutant (wl) showed a significant difference in leaf color from the wild-type plant (WT). In this study, we integrated the transcriptomes of wl and WT plants to screen differentially expressed genes related to leaf color variation. The results of transcriptome analysis showed that 84,163 unigenes were obtained after de novo assembly and the NR database annotated the largest number of unigenes, which accounted for 57.13%, followed by NT (43.02%), GO (39.84%), Swiss-Prot (39.25%), KEGG (36.06%), and COG (24.88%). Our finding showed that 2586 genes were differentially expressed in the two samples, including 1996 down-regulated genes and 590 up-regulated genes. GO analysis predicted that these differentially expressed genes (DEGs) participate in 12 cellular components, 20 biological processes, and 13 molecular function terms and KEGG analysis showed that metabolic pathways, plant-pathogen interaction, glycerophospholipid metabolism, endocytosis, plant hormone signal transduction, and ether lipid metabolism were enriched among all identified pathways. Through functional enrichment analysis of DEGs, we found that they were involved in chloroplast division and the biosynthesis of plant pigments, including chlorophyll, carotenoids, anthocyanin, and transcription factor families, which might be related to the formation mechanism of leaf color. Taken together, these results present insights into the difference in gene expression characteristics in leaves between WT and wl mutants and provide a new insight for breeding colorful leaf phenotypes in succulent plants.

Two new quinolinone glycoalkaloids from Chrysanthemum indicum L. and their antimicrobial activity.

Phytochemical investigation of Chrysanthemum indicum L. yielded two new quinolinone glycoalkaloids named as Chrysanthemumsides A-B (1-2). The structures of the new compounds were elucidated by analysis of their 1D- and 2D-NMR, HRESIMS and ECD calculations. Compounds 1-4 were evaluated for antimicrobial activity against the Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans, and the data showed that compound 2 had significant antimicrobial effects (MIC 3.9 to 7.8 µg/mL).

Integrated Proteomic and Metabolomic Analyses Provide Insights Into Acquisition of Embryogenic Ability in Agapanthus praecox.

Somatic embryogenesis (SE) is an ideal model for plant cell totipotency. Transition from somatic cells to embryogenic cells is the key to SE. The poor frequency of embryogenic callus (EC) induction has limited the application of SE in many plants, such as Agapanthus praecox. We performed large-scale, quantitative proteomic and metabolomic analyses with different callus differentiation directions (SE and organogenesis) and stages (initial SE and repetitive SE) to better understand the morphological, physiological, and molecular characteristics of the acquisition of embryogenic ability in A. praecox. Integrated proteomic and metabolomic analyses suggested that callus differentiation direction was potentially regulated by pathways related to carbohydrate and energy metabolism (fatty acid metabolism, pyruvate metabolism, glycolysis/gluconeogenesis, pentose and glucuronate interconversions, starch and sucrose metabolism, galactose metabolism, carbon fixation pathways in prokaryotes, carbohydrate digestion and absorption, and fructose and mannose metabolism), chromatin accessibility and DNA methylation, reactive oxygen species responses and resistance (ascorbate and aldarate metabolism), and plant hormonal signaling. As a validation, we found that carbon source combination and plant hormone regulation in the culture medium significantly affected the acquisition of embryogenic ability, thereby inducing EC. Interestingly, plant hormonal signaling-related genes showed different expression patterns significantly when callus cultured with different carbon sources. Thus, our results suggested that energy supply and hormone signal transduction seemed to cooperatively contribute to the activation of embryogenic ability. Altogether, this study revealed valuable information regarding the molecular and biochemical changes that occurred during EC induction and provided valuable foundation for comprehensive understanding of the mechanisms associated with SE and organogenesis in A. praecox.

The complete chloroplast genome of Hippeastrum vittatum (Amaryllidaceae).

Hippeastrum vittatum (L'Hér.) Herb. is a perennial herb in the Amaryllidaceae, which has been used as a medicinal and ornamental plant. Here, we assembled and characterized the complete chloroplast (cp) genome of H. vittatum by high throughput sequencing. As a result, the length of the complete cp genome is 158,082 bp with a canonical quadripartite structure, consists of a large single-copy region (LSC) of 86,165 bp, a small single-copy region (SSC) of 18,283 bp, and two inverted repeat (IR) regions of 26,817 bp, each. A total of 137 genes were identified, including 87 protein-coding genes, 42 tRNA genes, and 8 rRNA genes. The phylogenomic analysis was performed based on the complete cp genomes of 30 species, which revealed the closest relationship between H. vittatum and H. rutilum in the genus Hippeastrum.