The effect of dehydration on the growth rate of wild-type and cer10 mutant Arabidopsis thaliana

Abstract

The objective of this study was to determine whether dehydration treatment had a differentiated effect on the growth rate of wild-type and cer10 mutant Arabidopsis thaliana. We treated half of the mutant and wild-type replicates to dehydration conditions, which were watered up to 0.5 cm from the bottom of the tray weekly, and the other half with control conditions, which were watered up to 2.5 cm three times weekly. We measured the height of all the plants each week for four weeks. We then calculated the mean growth rates for the control wild type (5.31 ± 1.44 cm/week), control mutant (1.34 ± 0.82 cm/week), dehydration wild type (3.11 ± 1.88 cm/week), and dehydration mutant (2.80 ± 0.51 cm/week). We analyzed these data using a two-way ANOVA and found that dehydration did not have a statistically significant effect on the growth rate, while the presence of the cer10 mutation, which negatively affects very long chain fatty acid (VLCFA) synthesis resulting in waxless mutants, had a significant effect on the growth rate. Moreover, dehydration treatment slowed the growth rate of wild-type A. thaliana significantly more than the cer10 mutant. This was unexpected as it was assumed due to the lower cuticular wax load on mutant stems would increase water loss, which was predicted to cause the growth rate of the dehydration group mutants to be much lower than wild type.