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Title: The iojap gene in maize

Technical Report ·
DOI:https://doi.org/10.2172/771281· OSTI ID:771281

The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

Research Organization:
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (US)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
FG02-91ER20047
OSTI ID:
771281
Resource Relation:
Other Information: PBD: 1 Dec 2001; PBD: 1 Dec 2001
Country of Publication:
United States
Language:
English