ARS | Publication request: Differential RNA Expression of ßm1 during Late Seed Development in Cultivated and Wild Barleys Carrying Different ßmy1 Intron III Alleles and the Association with Beta-Amylase Activity

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 29, 2010
Publication Date: July 26, 2010
Citation: Vinje, M.A., Willis, D.K., Duke, S.H., Henson, C.A. 2010. Differential RNA Expression of ßm1 during Late Seed Development in Cultivated and Wild Barleys Carrying Different ßmy1 Intron III Alleles and the Association with Beta-Amylase Activity [abstract]. American Society of Plant Biologists Annual Meeting, July 31-August 4, 2010, Montreal, Canada. p. 80.

Technical Abstract: Four genotypes carrying different beta-amylase 1 (Bmy1) intron III alleles (Bmy1.a, Bmy1.b, Bmy1.c, and Bmy1.d) were analyzed for differences in Bmy1 mRNA accumulation, beta-amylase activity and protein, and total protein during late seed development. Wild barleys (Hordeum vulgare ssp. spontaneum) Ashqelon (Bmy1.c) and PI 296897 (Bmy1.d) had 2.5- to 3-fold higher Bmy1 mRNA levels than cultivars Legacy (Bmy1.a) and Harrington (Bmy1.b). The levels of Bmy1 mRNA were not signification different between Legacy and Harrington or Ashqelon and PI 296897. Ashqelon was found to have a novel Bmy1 amino acid signature that contained the preferred amino acids C115, A233, and S347. In all four genotypes Bmy1 mRNA levels increased from 17 to 19 DAA and did not change from 19 to 21 DAA. Ashqelon and PI 296897 also had more beta-amylase activity on a fresh weight basis than Legacy and Harrington at all developmental stages. The amount of total proteins extracted from Ashqelon and PI 296897 were significantly higher than Legacy and Harrington. Higher levels of total proteins extracted in Ashqelon and PI 296897 are the most likely explanation for their higher levels of beta-amylase activity, when measured on a fresh weight basis. When the beta-amylase activity is measured on a protein basis the large differences between the wild and cultivated barleys disappears. We propose that the higher levels of Bmy1 mRNA in Ashqelon and PI 296897 and subsequently the higher in beta-amylase activities when on a fresh weight basis are caused by higher seed storage protein expression and accumulation in wild barley.