The Cloning and Characterization of Two ROP/RAC G-Proteins from Gossypium Hirsutum

Rop/Rac proteins are plant-specific monomeric guanosine triphosphate-binding proteins (G-proteins) with important functions in plant development. Until recently, only three cotton (Gossypium hirsutum) Rop/Rac G-protein genes were sequenced, representing subfamilies III and IV of the plant monomeric Gprotein family. In this project, members of subfamilies II and I were cloned, sequenced, and named GhRac2 and GhRac3, respectively. Using real-time reverse transcription PCR, expression of GhRac2 was highest during fiber elongation, decreasing significantly when cellulose biosynthesis began. Transcript abundance of GhRac3 doubled between fiber elongation and secondary wall synthesis, remaining constant until 20 days post-anthesis. Expression of GhRac2 and GhRac3 was compared between the unfertilized ovules of Gossypium hirsutum, Texas Marker 1 and two near-isogenic fiber-impaired mutants. Expression of GhRac2 and GhRac3 was significantly higher in wild type ovules than in Ligon lintless, a mutant impaired in fiber elongation, but was not different in Naked Seed, a mutant impaired in fiber initiation.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year

2005

Author dc:creator

• Asprodites, Nicole

Contributors dc:contributor

• Triplett, Barbara A.
• Timpte, Candace
• Kim, Hee Jin

• Upland cotton
• GTPase
• fiber development
• gene expression
• cell wall
• cell elongation

Repository record dc:identifier

https://scholarworks.uno.edu/td/233

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-1237