pollen morphology of some species of the genus malus (rosaceae) was investigatedtaxonomically. all species are characteristic by tricolpate pollens. exine sculpturing is variable but is mostlystriate. however, species may differ in degree of density of ridges and their orientation. the exine patterns inm. trilobata and m. florentina are very similar and were characterized by short and very bran...

Zea mays (maize) pollen exines have been purified with the use of differential centrifugation and sucrose gradients, followed by mild detergent and high salt treatment. The final exine fraction is highly purified from other organelles and subcellular structures as assayed by transmission electron microscopy. Using mature maize pollen as the starting material, 0.2 to 0.3% of the total pollen pro...

The precise structure of the sporopollenin polymer that is the major constituent of exine, the outer pollen wall, remains poorly understood. Recently, characterization of Arabidopsis thaliana genes and corresponding enzymes involved in exine formation has demonstrated the role of fatty acid derivatives as precursors of sporopollenin building units. Fatty acyl-CoA esters synthesized by ACYL-COA ...

Sporopollenin is highly cross-linked polymer composed of carbon, hydrogen, and oxygen that is extraordinarily stable and has been found chemically intact in sedimentary rocks some 500 million years old. It makes up the outer shell (exine) of plant spores and pollen and when extracted it is in the form of an empty exine or microcapsule. The exines resemble the spores and pollen from which they a...

BACKGROUND AND AIMS Callose involvement in spore development is a plesiomorphic feature of land plants. Correlated light, fluorescence and immuno-electron microscopy was conducted on the developing spores of Physcomitrella patens to probe for callose. Using a bioinformatic approach, the callose synthase (PpCalS) genes were annotated and PpCalS and AtCalS gene families compared, testing the hypo...

We have explored methods to achieve excellent results in study of the pollen grain wall by using only one electron microscope, the scanning electron microscope (SEM). While the secondary electron imaging mode , the most common in use, has great value in characterizing the exine surface it is possible to obtain a more comprehensive representation of pollen grain walls by expanding the capability...

We investigated the pollen morphology of eight species Acalypha occurring in Bahia State, Brazil. Flower buds were collected from specimens deposited CEPEC and HUEFS herbaria. Pollen samples acetolyzed analyzed using both light scanning electron microscopy. The grains examined optical microscopy found to be small brevicolporate, with three six apertures elevations fastigium, had a psilate scabr...

Background & Aim: Satureja khuzistanica Jamzad. is an aromatic and medicinal perennial plant belongs to family mint (Lamiaceae). It is also an Iranian exclusive endemic species, its essential oil components are widely used in medicinal, culinary, and perfume industries. Experimental: Flowers were collected in 10 regions in Khuzistan and Lorestan provinces, Iran at early anthesis durin...

Anther cuticle and pollen exine are protective barriers for pollen development and fertilization. Despite that several regulators have been identified for anther cuticle and pollen exine development in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana), few genes have been characterized in maize (Zea mays) and the underlying regulatory mechanism remains elusive. Here, we report a novel ...