Hormone Induced Physiological Variation May Be Dependent On Ploidy Level Of Arabidopsis Thaliana

The term polyploid is used to describe a plant with more than two complete sets of chromosomes. Polyploids occur naturally in nature and are also observed in plants of agricultural importance like wheat. Understanding the physiological changes that can occur due to hormonal responses between diploids and tetraploids will assist in creating sturdy plants with a possible increase in food production and quality. Studies have shown how hormone regulation genetically differs between diploids from that of their respective tetraploids. However, there is still a gap in knowledge between the changes at the genetic level and the agriculturally important physiological difference between the two ploidy levels in response to hormones.

 In order to assess the physiological differences caused by hormone regulation, Arabidopsis thaliana diploid and tetraploid, seedlings were compared after being exposed to identical hormonal conditions. A. thaliana seeds were germinated on hormone-free media before being transferred to media containing varying concentrations of the 1-aminocyclopropane-1carboxlyic acid (ACC), 2,4-dichlorophenoxyacetic acid (2,4-D), Benzeneadenine (BA), Gibberellic acid (GA₃), and Indole-3-acetic acid (IAA). Root length and hypocotyl length were marked and measured daily for a period of ten days. On the tenth day lateral roots were counted and recorded. With this greater understanding of how hormonal regulation differs between ploidy levels, many agriculturally important advances could be developed to use ploidy as a way to target increasing crop yield and growth rate.