The plasma membrane proton pump (H ϩ -ATPase) found in plants and fungi is a P-type ATPase with a polypeptide sequence, structure, and in vivo function similar to the mammalian sodium pump (Na ϩ , K ϩ -ATPase). Despite its hypothetical importance for generating and maintaining the proton motive force that energizes the carriers and channels that underlie plant nutrition, genetic evidence for such a central function has not yet been reported. Using a reverse genetic approach for investigating each of the 11 isoforms in the Arabidopsis H ϩ -ATPase (AHA) gene family, we found that one member, AHA3, is essential for pollen formation. A causative role for AHA3 in male gametogenesis was proven by complementation with a normal transgenic gene and rescue of the mutant phenotype back to wild type. We also investigated the requirement for phosphorylation of the penultimate threonine, which is found in most members of the AHA family and is thought to be involved in regulating catalytic activity. We demonstrated that a T948D mutant form of the AHA3 gene rescues the mutant phenotype in knockout AHA3 plants, but T948A does not, providing the first in planta evidence in support of the model in which phosphorylation of this amino acid is essential. 1995). Its role in the phloem is presumed to be the conwhich is used directly by most secondary transporters trol of sugar loading for long-distance sucrose transport, to mediate the movement of solutes into and out of the a process that is critical for plant nutrition. ization studies were useful in determining the expresIn Arabidopsis, the electrochemical potential has been sion pattern of AHA3, we wanted to more closely and recorded at very negative levels, such as Ϫ230 mV, while directly examine the in planta role of this gene. To this the corresponding protein in animal cells, the Na ϩ ,K ϩ -purpose, we took a reverse genetic approach and characATPase, typically generates membrane potentials of only terized the effect of the absence of functional AHA3 ‫ف‬Ϫ100 mV (Hirsch et al. 1998). This potential, together on the plant. Through transmission studies, microscopic with a chemical gradient of protons, is thought to be analysis, and functional complementation, we have identiessential for diverse cellular processes, including nutrified an essential role for AHA3 in pollen development. ent transport, cellular expansion, and osmoregulation.Knockout plants are useful for structure/function exThus, the proton ATPase has been hypothesized to play periments, which are designed to test the roles of spea crucial role in many important physiological processes. cific domains. Results of heterologous experiments with The family of genes encoding plasma membrane yeast suggested that T948, at the extreme C terminus of H ϩ -ATPases in Arabidopsis has 11 members (Palmgren AHA3, is essential for activation of the pump. To test the 2001). Expression data have implicated differing roles hypothesis that this residue is important for functions of for family members in numerous tissues, includi...

Members of the Baha'i Faith have been subject to persecution in Iran since the mid-nineteenth century. Our investigation considers how collective identity among a Pacific Northwest Community has been constructed through the contexts of continued persecution in Iran and the development of religious texts, which helped to define the religious community. The texts found within the Baha'i Faith utilize metaphors of the body to construct religious identity. Many anthropologists have theorized on the usefulness of the body as a unit of study; in addition, recent attention by scholars has illustrated the intersection of the body and religion. A model is developed linking identity, consciousness, the body and experience that explains how collective identity is constructed. When considering the situation of the Baha'i community, this model has proven particularly useful in understanding how geographically disassociated people manage to construct social kinship within the context of religious persecution. In particular, American Baha'is describe the persecution of Baha'is in Iran as a collective experience, especially since the direct experience of persecution is far removed from their everyday living. Preliminary analysis of interviews with an American Baha'i, and an ex-patriot Iranian Baha'i reveal differences in constructions of identity.