Submitted to: Biennial Conference on Molecular and Cellular Biology of the Soybean
Publication Type: Abstract Only
Publication Acceptance Date: 6/18/2008
Publication Date: 7/20/2008
Citation: Thakare, D., Dinkins, R.D., Kumudini, S. 2008. The Important Positive and Negative Regulators of Feedback Loop of Circardian Clock are Conserved in Soybean and Exhibits Similar Diurnal Expression Pattern to Arabidopsis Thaliana Genes. Biennial Conference on Molecular and Cellular Biology of the Soybean. 12th Biennial Molecular and Cellular Biology of the Soybean Conference, Indianapolis, Indiana, July 20-23, 2008. http://genome.purdue.edu/soy2008/cgi/abstract_search.pl?search=Dinkins
Technical Abstract: Flowering time is a characteristic of great agronomic importance. Relative to such model species as Arabidopsis and rice, little is known of the genetic mechanisms controlling flowering in soybean. Soybean breeders have identified a series of seven loci, known as the E genes that mediated by photoperiod, condition flowering in soybean. The dominant E1 allele is considered to have the most dramatic effect in delaying flowering under an inductive long day (LD) photoperiod. Earlier studies have shown that soybean plants receive the flowering stimulus as early as 7 days after planting. In this study E-gene near isogenic lines OT93-5 (e1e1) and OT93-26 (E1E1) were selected and tested under a 20h LD photoperiod. Starting from 7 days after planting, tissue samples were collected every 3hrs over a 72-h period. The sampled tissue was used to conduct differential diurnal transcription analysis on putative soybean orthologs of Arabidopsis clock associated genes known to function as positive and negative regulator of interlocked transcription-translation feedback loops. Plants of OT93-26 flowered 7-10 later than OT93-5 under LD conditions. The putative clock genes tested exhibited circadian rhythmicity similar to that of Arabidopsis thaliana genes, indicating possible evolutionarily conserved molecular mechanism between these species. Slight shift in the diurnal cycle of some of the genes on day 8 was observed otherwise little differences were detected among the E-gene NILs tested. This suggests that the impact of the E1 allele on flowering time may not be due to regulation of the tested clock genes orthologs during this time period.