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Abstract Detail


Recent Topics Posters

Acevedo, Diana S. [1], Sundberg, Marshall [2].

 

Role of teosinte branching gene (tb1) on the development and evolution of Zea Mays

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 Maize, Zea mays L., is the only domesticated taxon in the genus Zea, which also includes several species of grass commonly called teosinte. This well known domestication resulted from an increase in apical dominance, which refers to the suppression of axillary branches along the main stem. Previous molecular analyses have suggested that teosinte branched gene (tb1) is one of the genes responsible for the evolution of cultivated maize, the unique branching morphology in teosinte, and the repression of long branches in maize. The objective of this study was to design (tb1) specific primers for qt- RT-PCR to compare the expression of tb1 in three different maize subspecies at different developmental stages, and among tissues. DNA was extracted from three maize species: Zea mays ssp. Parviglumis, Zea mays land race Palomero Toluqueño, and Zea mays mays. c.v. B73. The tb1 gene was isolated, cloned, and sequenced for each species for primer design. The specific (tb1) gene primers are located near the 3â untranslated region of the gene. Axillary buds and branch tissues were dissected and flash frozen upon collection. Frozen tissue was ground on a mortar and crushed with a pestle under liquid nitrogen. Total RNA was isolated and treated to ensure that no genomic DNA was left in the samples. The Reverse transcriptase reactions were synthesized using 1ug of total RNA with (dT) primers. qt- RT-PCR was performed  using ubiquitin as the reference gene primer to confirm cDNA synthesis. Each sample was analyzed by comparing the DCT values (CT calibrator â CT sample) for the target gene (tb1) relative to the reference gene (ubiquitin). Our data showed low levels of (tb1) expression in the vegetative axillary buds of all species and high levels in the ears and shanks of maize at later stages of development.  Unexpected results showed high levels of (tb1) expression   in the branch shanks of teosinte, especially at higher orders of branching as well as the low, but measurable, activity in teosinte ears. These data suggest that the interaction between tb1, and apical dominance/branching may be more nuanced than previously recognized. In addition, we concluded that the changes in expression of (tb1) might be a result of phenotypic plasticity, suggesting that the geographical location, altitude, climate and temperature have played an important role in the evolution and adaptive phenotypical characteristics that have occur in the genus Zea.

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2010 microMORPH training grant awardees


1 - Emporia State University, Biological Sciences, 1200 Commercial Street, Emporia, KS, 64801, USA
2 - Emporia State University, Department Of Biological Sciences, 1200 COMMERCIAL, EMPORIA, KS, 66801, USA

Keywords:
gene expression
tb1
Evolution
maize.

Presentation Type: Recent Topics Poster
Session: TBA
Location: /
Date: Thursday, January 1st, 1970
Time: TBA
Number:
Abstract ID:1336


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