Abstract Detail

Physiological Section

Chitnis, Vijaya R. [1], Gao, Feng [1], Yao, Zhen [1], Jordan, Mark C. [2], Ayele, Belay T. [1].

After ripening induced transcriptional changes of hormonal genes in wheat seeds.

The maintenance and release of physiological seed dormancy is regulated by plant hormones, which is associated with their concentration and tissue sensitivity. Seed after ripening (AR), which releases seeds from dormancy status, causes several physiological changes including alteration in the expression of genes involved in the metabolism and signaling of several phytohormones. This study performed comparative expression analysis of ethylene (ET), brassinosteroids (BR), and cytokinin (CK) related genes between dormant (D) and AR wheat seeds. Ninety five percent of AR seeds germinated within 24 hours, whereas only 11% of the corresponding dormant seeds showed germination after 7 days of imbibition. The release of dormancy in AR seeds found to be associated with the up-regulation of BR biosynthesis genes de-etiolated 2 and dwarf 4, and positive regulators of BR signaling such as BR-signaling kinases; and the down-regulation of negative regulator of BR signaling, BR insensitive 2. Our data suggest increased formation and signaling of BR during imbibition in AR seeds; promoting dormancy breakage and seed germination. Our data also supports the role of ET in regulating the release of dormancy as the ET biosynthesis and signaling genes, including ACC oxidase, ET receptor protein, and ET response sensor 1 exhibited upregulation in imbibing AR as compared to the D seeds. Cytokinin might also have a role in dormancy regulation, as CK-related genes, lonely guy, zeatin O-glucosyltransferases and pseudo-response regulator show differential expression between D and AR seeds. These results help in our further understanding of the role of plant hormones in wheat seed dormancy.

1 - University of Manitoba, Plant Science, 222, Agriculture Building, Department of Plant Science, University of Maniotba, Winnipeg, MB, R3T 2N2, Canada
2 - Agriculture and Agri-Food Canada, Cereal Research Center, Morden, 101 Route 100, Unit 10, Morden, MB, R6M 1Y5, Canada

Keywords:
After ripening
Ethylene
Brassinosteroids
cytokinin
seed dormancy
gene expression
wheat.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PPS003
Abstract ID:770
Candidate for Awards:Physiological Section Best poster presentation