Many arboreal forms of the genus Croton (ca. 800 spp.), amply distributed in the Americas, have latex‐producing cells in their bark, which is widely used in traditional medicine to treat skin infections and some forms of cancer. Studies validate its ethnomedicinal use—more than 20 pharmaceutically important secondary metabolites have been reported for its latex and bark—but anatomical and ecological studies are scarce. Given this species’ ample distribution, laticifer abundance could be affected by the environment. We tested this for genetically similar trees growing in two types of vegetation in Veracruz, Mexico at sites commonly visited by traditional doctors. We describe the bark anatomy of C. draco, focusing on the laticifers, histochemically characterize the bark and the latex extracted from it, and document differences in laticifer abundance in the two environments. We have also identified another cell type (what we call type B) in the secretory latex system and describe it histochemically and microscopically. The location of bark cells that contain essential oils is reported here for the first time. Given the genetic similarity of the trees at both sites, the between‐site variation in the number of laticifers in stem and branch bark appears to be an effect of the environment.

BackgroundCroton draco is an arboreal species and its latex as well as some other parts of the plant, are traditionally used in the treatment of a wide range of ailments and diseases. Alkaloids, such as magnoflorine, prevent early atherosclerosis progression while taspine, an abundant constituent of latex, has been described as a wound-healer and antitumor-agent. Despite the great interest for these and other secondary metabolites, no omics resources existed for the species and the biosynthetic pathways of these alkaloids remain largely unknown.ResultsTo gain insights into the pathways involved in magnoflorine and taspine biosynthesis by C. draco and identify the key enzymes in these processes, we performed an integrated analysis of the transcriptome and metabolome in the major organs (roots, stem, leaves, inflorescences, and flowers) of this species. Transcript profiles were generated through high-throughput RNA-sequencing analysis while targeted and high resolution untargeted metabolomic profiling was also performed. The biosynthesis of these compounds appears to occur in the plant organs examined, but intermediaries may be translocated from the cells in which they are produced to other cells in which they accumulate.ConclusionsOur results provide a framework to better understand magnoflorine and taspine biosynthesis in C. draco. In addition, we demonstrate the potential of multi-omics approaches to identify candidate genes involved in the biosynthetic pathways of interest.

Se presentan 17 nuevos registros pertenecientes a 11 familias y 13 géneros de angiospermas para los municipios de Acultzingo y Maltrata, en el estado de Veracruz, además de dos especies que son redescubiertas para la entidad. Se aportan datos sobre el hábitat, distribución y endemismo de las especies y se confirma que esta zona forma parte de la provincia florística de Tehuacán-Cuicatlán.

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Antecedentes y Objetivos: Hyptis suaveolens es una planta bien conocida en América Latina por sus propiedades medicinales. A pesar de sus diversos usos en la medicina tradicional, hay pocos reportes de su composición química. Además, se conoce su actividad contra bacterias que afectan al ser humano, pero existen pocos reportes acerca de su actividad sobre bacterias fitopatógenas, específicamente sobre aquellas que afectan cultivos. En este contexto los principales objetivos de este trabajo fueron determinar la actividad antibacteriana de hojas de H. suaveolens en bacterias fitopatógenas y su perfil fenólico, con el fin de contribuir al conocimiento de la composición fitoquímica y bioactividad de H. suaveolens para aplicaciones fitosanitarias.Métodos: El material vegetal fue colectado y las partes aéreas se secaron, molieron y extrajeron con metanol. El extracto crudo fue probado contra dos cepas bacterianas fitopatógenas (Chryseobacterium sp. y Pseudomonas sp.). Finalmente, se identificaron y cuantificaron compuestos fenólicos utilizando cromatografía de líquidos de ultra alta resolución acoplada a espectrometría de masas. Resultados clave: El extracto crudo de H. suaveolens mostró una actividad antibacteriana moderada en contra de Chryseobacterium sp., y se identificaron y cuantificaron 14 compuestos fenólicos, destacando al ácido rosmarínico, el cual mostró ser el más abundante, seguido de quercetina-3-glucósido y rutina. Seis compuestos fenólicos fueron identificados y cuantificados por primera vez en H. suaveolens.Conclusiones: En este estudio se demostró la actividad antibacteriana de las hojas de H. suaveolens y su correlación con la identificación y cuantificación de 14 compuestos fenólicos, particularmente con la presencia del ácido rosmarínico.