Members of the ELMOD protein family specify formation of distinct aperture domains on the Arabidopsis pollen surface

Pollen apertures, the characteristic gaps in pollen wall exine, have emerged as a model for studying the formation of distinct plasma membrane domains. In each species, aperture number, position, and morphology are typically fixed; across species they vary widely. During pollen development, certain plasma membrane domains attract specific proteins and lipids and become protected from exine deposition, developing into apertures. However, how these aperture domains are selected is unknown. Here, we demonstrate that patterns of aperture domains in Arabidopsis are controlled by the members of the ancient ELMOD protein family, which, although important in animals, has not been studied in plants. We show that two members of this family, MACARON (MCR) and ELMOD_A, act upstream of the previously discovered aperture proteins and that their expression levels influence the number of aperture domains that form on the surface of developing pollen grains. We also show that a third ELMOD family member, ELMOD_E, can interfere with MCR and ELMOD_A activities, changing aperture morphology and producing new aperture patterns. Our findings reveal key players controlling early steps in aperture domain formation, identify residues important for their function, and open new avenues for investigating how diversity of aperture patterns in nature is achieved.

Members of the ELMOD protein family specify formation of distinct aperture domains on the Arabidopsis pollen surface

Pollen apertures, the characteristic gaps in pollen wall exine, have emerged as a model for studying the formation of distinct plasma-membrane domains. In each species, aperture number, position, and morphology are typically fixed; across species they vary widely. During pollen development certain plasma-membrane domains attract specific proteins and lipids and become protected from exine deposition, developing into apertures. However, how these aperture domains are selected is unknown. Here, we demonstrate that patterns of aperture domains in Arabidopsis are controlled by the members of the ancient ELMOD protein family, which, although important in animals, has not been studied in plants. We show that two members of this family, MACARON (MCR) and ELMOD_A, act upstream of the previously discovered aperture proteins and that their expression levels influence the number of aperture domains that form on the surface of developing pollen grains. We also show that a third ELMOD family member, ELMOD_E, can interfere with MCR and ELMOD_A activities, changing aperture morphology and producing new aperture patterns. Our findings reveal key players controlling early steps in aperture domain formation, identify residues important for their function, and open new avenues for investigating how diversity of aperture patterns in nature is achieved.

Identification of Pollen Characteristics as Apis cerana Feed Sources in Honeycomb, in Serang Purbalingga

Serang Purbalingga village is a fertile area and has the potential for the development of Apis cerana honeybee business. Honeybee products are known to have high economic value. The development of honeybee business will be better if supported by the avaibility of pollen from flowering plants as feed sources. Pollen that use to be A. cerana feed sources are taken from plants flower around the beehive and matched with pollen inside honeycomb. The purpose of this research is to determine the diversity and character of pollen from plants found around beehive and inside A. cerana honeycomb. This research conducted by descriptive survey method where the data obtained from field used as material for analysis and describing the characteristics of pollen found. Variable in this research is pollen characters with parameters are pollen units, size, shape, apertures and ornamentation. Based on results, there are 23 species of plants included in 17 families found around the beehive with varying of pollen shape, namely spheroidal, prolate-spheroidal, sub-prolate, and prolate. The smallest to largest pollen sizes are minutae, mediae, and magnae. Types of pollen ornamentations are rugulate, reticulate, echinate, psilate, scabrate, to baculate. Pollen apertures are varies monosulcate, monoporate, tricolporate, tricolpate, tetracolpate, hexacolpate to syncolpate. Pollen characters inside honeycomb are identical to 12 pollen of plant species found around the beehive where the pollen shape are spheroidal, prolate-spheroidal, sub-prolate and prolate. There are several types of ornamentation, namely reticulate, rugulate, echinate, psilate and sacbratte. Apertures are varies from monosulcate, monoporate, tricolporate, tricolpate to syncolpate. Key words : Apis cerana, characters,diversity, pollen, Purbalingga

Metabolic Alterations in Male-Sterile Potato as Compared to Male-Fertile

The common potato, Solanum tuberosum L., is the fourth most important agricultural crop worldwide. Until recently, vegetative propagation by tubers has been the main method of potato cultivation. A shift of interest to sexual potato reproduction by true botanical seeds is due to the appearance of a new hybrid seed breeding strategy whose successful application for many crop species has been supported by male sterility. This investigation was focused on the study of differences in the metabolite profiles of anthers at the mature pollen stage from male-fertile and male-sterile genotypes of S. tuberosum. Application of gas chromatography coupled with a mass spectrometry method allowed detection of metabolic profiles for 192 compounds. Further data analysis with several libraries fully identified 75 metabolites; a similar amount was defined up to the classes. Metabolic profiles in the anthers of fertile genotypes were significantly distinguished from male-sterile ones by the accumulation of carbohydrates, while the anthers of sterile genotypes contained a higher amount of amino acids. In comparison with male-fertile plants, male-sterile genotypes had undeveloped pollen grain characters; i.e., smaller grain size, a thicker exine, “permanent tetrads” that failed to disintegrate into microspores, and the absence of pollen apertures that might be due to a disorder in the metabolism of carbohydrates and fatty acids.