Genes essential for gametophyte development and fertilization have been identified and studied in detail; however, genes that fine-tune these processes are largely unknown. Here, we characterized an unknown Arabidopsis gene, GTP-BINDING PROTEIN RELATED1 (GPR1). GPR1 is specifically expressed in ovule, pollen, and pollen tube. Enhanced green fluorescent protein-tagged GPR1 localizes to both nucl...

Apomictic plants reproduce asexually through seeds by avoiding both meiosis and fertilization. Although apomixis is genetically regulated, its core genetic component(s) has not been determined yet. Using profiling experiments comparing sexual development in maize (Zea mays) to apomixis in maize-Tripsacum hybrids, we identified six loci that are specifically downregulated in ovules of apomictic ...

The AGAMOUS (AG) gene is necessary for stamen and carpel development and is part of a monophyletic clade of MADS-box genes that also includes SHATTERPROOF1 (SHP1), SHP2, and SEEDSTICK (STK). Here, we show that ectopic expression of either the STK or SHP gene is sufficient to induce the transformation of sepals into carpeloid organs bearing ovules. Moreover, the fact that these organ transformat...

We present a novel microsystem-based assay to assess and quantify pollen tube behavior in response to pistil tissues. During plant reproduction, signals from female tissues (pistils) guide the sperm-carrying pollen tube to the egg cell to achieve fertilization and initiate seed development. Existing pollen tube guidance bioassays are performed in an isotropically diffusive environment (for exam...

The present investigation deals with morphological and embryological studies of Rhynchelytrum repens (Willd) C.E. Hubbard. The development of anther walls are found to be Monocotyledonous type. The tapetal cells are substantially large, glandular and uninucleate. The middle layer is ephemeral and their cells are small in size. It is sandwiched between endothecial and tapetal layer. The endothec...

The generation of novel hybrid lines is critically limited by the compatibility between pollen and pistil and their ability to achieve successful seed formation. Fertilization in flowering plants requires the successful transfer of the male gametes from the pollen grain to the egg contained within an ovule. This occurs via the formation of a tubular protrusion from the pollen grain – the pollen...

In hermaphroditic plants, female reproductive success often varies among different positions within an inflorescence. However, few studies have evaluated the relative importance of underlying causes such as pollen limitation, resource limitation or architectural effect, and few have compared male allocation. During a 2-year investigation, we found that female reproductive success of an acropeta...

The development of gametophytes relies on the establishment of a haploid gametophytic generation that initiates with the specification of gametophytic precursors. The majority of flowering plants differentiate a single gametophytic precursor in the ovule: the megaspore mother cell. Here we show that, in addition to argonaute9 (ago9), mutations in other ARGONAUTE (AGO) genes such as ago4, ago6, ...

This study investigated the usefulness of floral characters as a potential indicator of breeding system in the Brassicaceae. Initially, pod set, seed set and pollen tube growth experiments were carried out to confirm the breeding systems of 53 lines representing 25 different cultivated and weedy species from the Brassicaceae. The results of the pod set tests clearly differentiated between self-...

The precise guidance of the pollen tube to the embryo sac is critical to the successful sexual reproduction of flowering plants. We demonstrate here the guidance of the pollen tube to the embryo sac in vitro by using the naked embryo sac of Torenia fournieri, which protrudes from the micropyle of the ovule. We developed a medium for culture of both the ovule and the pollen tube of T. fournieri ...