distinct from whole mature pollen [11] is consistent with our finding that miRNAs do not appear to act across the vegetative/sperm cell interface. Our data clearly reveal the presence of different and cell-autonomous differences in miRNA activity in the mature pollen grain of Arabidopsis. They further highlight the importance of promoter specificity when using amiRs to target mRNAs in rapidly d...

The male gametophyte of Arabidopsis is a three-celled pollen grain that is thought to contain almost all the mRNAs needed for germination and rapid pollen tube growth. We generated a reference map of the Arabidopsis mature pollen proteome by using multiple protein extraction techniques followed by 2-DE and ESI-MS/MS. We identified 135 distinct proteins from a total of 179 protein spots. We foun...

during past few years, the cupressus arizonica has been abundantly planted in tehran, causing a significant increase of allergic diseases from the middle of winter to the beginning of spring. the aim of this study was the comparison of pollen protein content in two major varieties of c. arizonica planted in tehran, including c. arizonica var. arizonica and c. arizonica var. glabra , in order to...

Tapetosomes are abundant organelles in tapetum cells during the active stage of pollen maturation in Brassicaceae species. They possess endoplasmic reticulum (ER)-derived vesicles and oleosin-coated lipid droplets, but their overall composition and function have not been established. In situ localization analyses of developing Brassica napus anthers revealed flavonoids present exclusively in ta...

During maturation, pollen undergoes a period of dehydration accompanied by the accumulation of compatible solutes. Solute import across the pollen plasma membrane, which occurs via proteinaceous transporters, is required to support pollen development and also for subsequent germination and pollen tube growth. Analysis of the free amino acid composition of various tissues in tomato revealed that...

This study was conducted to investigate the response of maize (Zea mays) male and female mature reproductive tissues to temperature stress. We have tested the fertilization abilities of the stressed spikelets and pollen using in vitro pollination-fertilization to determine their respective tolerance to stress. The synthesis of heat shock proteins (HSPs) was also analyzed in male and female tiss...

During maturation, pollen undergoes a period of dehydration accompanied by the accumulation of compatible solutes. Solute import across the pollen plasma membrane, which occurs via proteinaceous transporters, is required to support pollen development and also for subsequent germination and pollen tube growth. Analysis of the free amino acid composition of various tissues in tomato revealed that...

The pollen wall consists of an exine and an intine. The mechanism underlying its formation is not well understood. Glycosyltransferases catalyze the modification of biological molecules by attaching a single or multiple sugars and play key roles in a wide range of biological processes. We examined the role of GLYCOSYLTRANSFERASE1 (OsGT1) in pollen wall development in rice (Oryza sativa). This g...

The perception and response of pollen tubes to the female guidance signals are crucial for directional pollen tube growth inside female tissues, which leads to successful reproduction. In pursuing the mechanisms underlying this biological process, we identified the Arabidopsis (Arabidopsis thaliana) abnormal pollen tube guidance1 (aptg1) mutant, whose pollen tubes showed compromised micropylar ...

Pollen grains are the mature male (haploid) gametophyte of higher plants. These tiny organs (10-100 IJ.m in diameter) develop in the anthers (Stanley and Linskens, 1974). When the flower opens the anthers become exposed to the environment and dehydration triggers a mechanism for release of the pollen. In the process, the pollen also dehydrates. Though the pollen of most species can withstand dr...