Project Number: 3655-21430-009-02
Project Type: Specific Cooperative Agreement

Start Date: Aug 02, 2010
End Date: Aug 02, 2012

Objective:
1. To determine when bioactive GAs reach the aleurone tissue in the superior malting barley cultivar, Morex. Results will be related to the temporal decline in the the GA-response inhibitor protein, DELLA, and the appearance of alpha-amylase messenger RNA. 2. To determine the source, within the barley seed, of these GAs. 3. To determine whether this temporal bracketing can be used to assess potential malting quality of other new barley varieties.

Approach:
The gibberellin (GA) hormone(s) control hydrolytic enzyme production in the seeds aleurone layer. The origin of these GAs is still unknown. Seed tissues from the Morex malting barley will be carefully dissected and pooled for hormone analysis. The tissue extracts will be spiked with various internal control GAs and analyzed by GC-Mass spectrometry. The deduced GA types will indicate the biosynthesis pathway used by the aleurone, if GA synthesis indeed occurs in the aleurone. Alternatively, GA intermediates produced only in the root/shoot axis or in the scutellum will determine whether the GA comes from either of these tissues. The temporal profile of active GA accumulation in these tissues will be correlated with the rise in high-pI alpha-amylase messenger RNA production in the aleurone.