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Abstract Detail



Developmental and Structural Section

Srivastava, Renu [1], Deng, Yan [1], Quilichini, Teagen [2], Dong, Haili [1], Horner, Harry T. [3], Howell, Stephen [1].

Temperature stress protection of pollen formation by the unfolded protein response.

The unfolded protein response (UPR) is elicited by ER stress during vegetative growth in plants. The UPR is constitutively active in flowers, particularly in anthers, where there are high demands for secretion during pollen development. Pollen development and pollination are the most sensitive stages to temperature stress in most plants and we have found that the UPR protects male gametophyte development from temperature stress. Double mutants ire1a ire1b and ire1b bzip28 affecting the UPR signaling pathway in Arabidopsis are conditionally male sterile at modestly elevated temperatures. The temperature-sensitive defects in the double mutants are sporophytic and impact the tapetum in its support of male gametophyte development. The defects at elevated temperatures also disrupt the deposition of the pollen coat, which leads to clumping and collapse of many pollen grains. In comparison to wild type, the double mutants showed a strong shift in intrinsic fluorescence of developing pollen indicating compositional changes in the pollen wall. Pollen in the ire1a ireb mutant phenocopied quartet (qrt) mutants despite the fact that there was no suppression of QRT gene expression in this mutant. The impact of the double mutants on the stress transcriptome in vegetative tissues was quite different from that in flowers where it affects the expression of genes encoding components of the vesicle transport system and pollen coat formation. These findings are consistent with the concept that the UPR protects pollen formation from temperature stress by promoting the expression of genes encoding components of the pollen coat and of genes involved in the orderly transport of coat substrates to the pollen wall.


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1 - Iowa State University, Genetics, Development and Cell Biology, Ames, IA, 50011, USA
2 - University of British Columbia, Botany, 6270 University Boul, Vancouver, BC, V6T 1Z4, Canada
3 - Iowa State University, Genetics, Development And Cell Biology Dept, 3A Bessey Hall, Ames, IA, 50011-1020, USA

Keywords:
Arabidopsis
mutants
pollen formation
temperature stress
unfolded proteins.

Presentation Type: Oral Paper:Papers for Sections
Session: 69
Location: Salon 11/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 1:45 PM
Number: 69002
Abstract ID:76
Candidate for Awards:None


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