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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Cotton Structure and Quality Research » Research » Publications at this Location » Publication #184101
Title: CLONING AND CHARACTERIZATION OF THREE ROP/RAC G-PROTEINS FROM GOSSYPIUM HIRSUTUM

Author
item ASPRODITES, N - UNO
item Triplett, Barbara

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2004
Publication Date: 1/4/2005
Citation: Asprodites, N. 2005. Cloning and characterization of three Rop/Rac G-proteins from Gossypium hirsutum. M.S. thesis, Department of Biological Sciences, University of New Orleans, pp. 91.

Interpretive Summary:

Technical Abstract: 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 L.) Rop/Rac G-protein genes were sequenced, representing subfamilies 3 and 4 of the plant monomeric G-protein family. In this project, members of subfamilies 2 and 1 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 G. 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.