Objective: Microscopic characterization of a plant is a valuable method for accurate identification of the plant powder. The plants of Phlomis genus (Lamiaceae) are mostly distributed in the north and west of Iran with about 10 endemic species. In the present investigation, microscopic characterization of some Phlomis species including Phlomis bruguieri, Phlomis rigida, Phlomis kurdica, and Phl...

Structures on the surfaces of leaves, such as dense layers of non-glandular trichomes, strongly affect phylloplane mite activities. On the other hand the feeding of eriophyoid mites on leaf surfaces can cause hyperplasia of leaf trichomes (erinea formation). In many cases the hyperplasia is accompanied by the accumulation of pigments within trichome cells, causing an impressive red-brown colour...

The genus Desmodium is represented in Santa Catarina State, Brazil, by 13 species, all with lomen- taceous fruits. Shape, size and isthmus margin of loments vary, while the surface is glabrous, or covered by trichomes of different types. Morphological diversity of trichomes becomes particularly relevant to taxonomic description. The trichome types present on the surface of Desmodium fruits prov...

Some plants produce methylketones as potent defense compounds against various insects. Wild tomato (Solanum habrochaites), a relative of the cultivated tomato (Solanum lycopersicum), synthesizes large amounts of 2-methylketones in its glandular trichomes, but cultivated tomato trichomes contain little or no methylketones. Two enzymes, Solanum habrochaites methylketone synthase1 (ShMKS1) and ShM...

Glandular secreting trichomes of cultivated tomato (Solanum lycopersicum) and close relatives produce a variety of structurally diverse volatile and non-volatile specialized ('secondary') metabolites, including terpenes, flavonoids and acyl sugars. A genetic screen is described here to profile leaf trichome and surface metabolite extracts of nearly isogenic chromosomal substitution lines coveri...

A DNA regulatory fragment was isolated from the promoter region of the OASA1 gene, encoding the cytosolic O-acetylserine(thiol)lyase enzyme that is highly expressed in Arabidopsis thaliana trichomes. This DNA fragment has been named an ATP fragment and comprises 1435 bp of the genomic region upstream of the OASA1 gene and 375 bp of the transcriptional initiation start site containing the first ...

Herbivory can induce several structural and functional alterations in the plant secretory system. Glandular trichomes are the main sites of production of volatile organic compounds (VOCs) with several chemical properties in Lamiaceae species. Ocimum species usually have three morphotypes of glandular trichomes (morphotype I is peltate and has a wide four-celled head; morphotype II is capitate a...

The olive leaf trichomes are multicellular peltate hairs densely distributed mainly at the lower leaf epidermis. Although, non-glandular, they have gained much attention since they significantly contribute to abiotic and biotic stress tolerance of olive leaves. The exact mechanisms by which olive trichomes achieve these goals are not fully understood. They could act as mechanical barrier but th...