Paramutation and mutation of R (ch) in maize

Area of Science:

• Plant genetics
• Maize genetics
• Gene regulation

Background:

• The R locus in maize controls anthocyanin pigmentation.
• R(ch) allele exhibits a broad pigmentation pattern affecting aleurone, anthers, silks, and pericarp.

Purpose of the Study:

• To investigate the paramutational and mutational behavior of the R(ch) allele in maize.
• To elucidate the genetic structure and regulatory mechanisms of the R(ch) locus.

Main Methods:

• Paramutation assays to assess R(ch) behavior in aleurone and pericarp.
• Mutation experiments to identify components within the R(ch) locus.
• Analysis of gene interactions with independent genes.

Main Results:

• R(ch) is paramutable in aleurone but not pericarp, showing differential sensitivity to R(st).
• Mutation experiments indicate R(ch) is a compound locus with at least four components: P, Si, Ch, and S.
• Interactions with other genes support the multi-component model of R(ch).

Conclusions:

• The R(ch) locus is a complex genetic unit with distinct components controlling specific pigmentation traits.
• Differential sensitivity of R(ch) components to R(st) suggests intricate regulatory mechanisms.
• Understanding R(ch) structure provides insights into gene regulation and paramutation in plants.