ARS | Publication request: EFFECTS OF ETHYLENE IN BARLEY (HORDEUM VULGARE L.) TISSUE CULTURE REGENERATION.

Submitted to: North American Barley Research Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 2005
Publication Date: July 10, 2005
Citation: Jha, A.K., Dahleen, L.S., Suttle, J.C. 2005. Effects of ethylene in barley (Hordeum vulgare L.) tissue culture regeneration. North American Barley Research Workshop Proceedings, Red Deer, Alberta. p. 171.

Technical Abstract: Ethylene is a gaseous plant hormone that regulates numerous cellular processes from germination to flowering and senescence. It is produced under stress conditions such as tissue culture and can be physiologically significant in-vitro due to enclosed conditions. This study was conducted to determine genotype-dependent ethylene production and its role in regeneration of barley (Hordeum vulgare L.) callus. Six barley cultivars were examined and found to produce different amounts of ethylene during culture. The highest regeneration was observed in cultivars generating the most ethylene. Ethylene production was correlated with regeneration rates (r2= 0.90625). There were no significant genotype by stage interactions for either ethylene production or green plant regeneration. The media was modified by adding the ethylene precursor, ACC (1-amino-cyclopropane-1-carboxylic acid) or the ethylene antagonist silver nitrate (AgNO3) to the media at different stages of callus culture to determine the effects of ethylene during plant regeneration. Highest regeneration in Morex was observed when AgNO3 was added to maintenance stages (M-1, M-2) and lowest regeneration when AgNO3 was applied to the regeneration stage compared to the control. In Golden Promise, AgNO3 added throughout the second maintenance and regeneration stages showed the highest regeneration compared to control. Regeneration was significantly affected with addition of ACC in Morex and highest when ACC was added at the second maintenance stage. Golden Promise did not show improved regeneration when ACC was added at any time. Regeneration was highest for the control. Further manipulation of ethylene synthesis and/or action will be used to identify critical timing and duration for ethylene to effects on plant regeneration from recalcitrant genotypes. Ethylene exposure for briefer time periods will help pinpoint the specific stages when ethylene should be manipulated.