Molecular and biochemical characterization of thevp12 mutant of maize (Zea mays L.)

The mutant vp12 is a single locus mutation that conditions lemon endosperm, viviparous embryos and white seedlings. Previous genetic analysis demonstrated that vp12 is not allelic to other viviparous mutants of maize. In this work, the objectives are to characterize vp12 at both molecular and biochemical levels. First, levels of the hormone ABA were measured at several stages during embryo development and also in isolated organs, under drought stress. In mutant embryos, ABA levels were lower than in normal ones, at all stages analyzed. Under drought stress, mutant organs from both 3-day and 9-day old seedlings accumulated less ABA than corresponding normal organs. However, the hormone levels in some stressed mutant organs, such as roots and leaves, are higher than in non-stressed organs. These results suggest that the ability of ABA synthesis is not completely blocked in vp12. Expression of several ABA-responsive genes, such as Em, glb1, glb2 and rab17, was detected in RNA extracts from mutant immature embryos, despite the lower ABA levels observed in those. In addition, transcripts corresponding to vp1, a transcriptional activator for embryo ABA-mediated responses, were also observed in mutant embryos. Therefore, it can be suggested that the ABA signal transduction pathway is not impaired in vp12 embryos.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Crop Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Maluf, Mirian Perez

Contributors dc:contributor

• Sachs, Martin M.

• Biology, Molecular
• Biology, Genetics
• Biology, Plant Physiology

Statement dc:rights

• Copyright 1996 Maluf, Mirian Perez

Language dc:language

eng

Identifier

AAI9625162
(UMI)AAI9625162

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21846