Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2008
Publication Date: 10/31/2008
Citation: Tyagi, N., Dahleen, L.S. 2008. Expression Analysis of Ethylene Biosynthesis and Receptor Genes From Barley Embryo and Tissue Culture pg 36 . Meeting Abstract. Interpretive Summary:
Technical Abstract: Ethylene affects regeneration of green plants from barley tissue culture. With the availability of the HarvEST barley database and barley GeneChip, genome-wide expression studies have focused on differential development between Morex and Golden Promise at various stages of plant growth. The data from these studies are available from the Barley Gene Atlas and provide an excellent source for datamining genes of interest. We used ethylene biosynthesis genes 1-aminocyclopropane-l-carboxylic acid synthase (ACS) and ACC oxidase (ACO), and ethylene receptor 1 (ETR1) as search criteria and selected the respective unigenes and their probes from HarvEST. The probes were used to examine the expression results from embryo, coleoptile and radicle tissue in the Barley Gene Atlas. The consensus sequences from a set of same unigenes as above were used to design primers that were tested on RNA (cDNA) extracted from Morex and Golden Promise at various tissue culture stages. The results from datamining and cDNA experiments were compared. The different probes from same unigene gave variable expressions in the two cultivars. The cDNA experiment indicated that ACS-6923 was constitutively expressed in both cultivars, while ACS-13017 and ACS-1108 showed differential expression. Similar results were seen for ACO. The unigenes ACO-1780 and ACO-1786 tested in Morex were differentially expressed in different stages of tissue culture. In the Barley Atlas experiment, ACO-1781 was the most differentially expressed ACO between the cultivars. The expression of ACO-1784 varied considerably between tissues; 38% higher in Morex embryos, 90% higher in Morex coleoptiles, but almost three times higher in Golden Promise radicle tissue. cDNA expression of ETR1 was not studied and the data from Barley Gene Atlas indicates constitutive expression. The dataming expression studies confirm our findings but also show some interesting differences as the same unigenes are represented by different probes and more than one probe exists for some unigenes. In most cases the expression in Morex was higher than Golden Promise, sometimes by as much as 90%. This variation in expression could contribute to the differential performance of these cultivars in tissue culture and can be used to modify the expression of these genes to achieve higher regeneration.