Expression profiles of ethylene receptor genes in cassava stems after drought, osmotic, or salt treatment.

<p>The threshold cycle (Ct) values of target and <i>MeActin</i> genes were obtained through qRT-PCR. The relative expression values for all selected genes was quantified using the 2^-ΔΔCt method, where ΔΔCt = (Ct _{target gene} − Ct _{<i>MeActin</i> gene}) _treatment − (Ct _{target gene} − Ct _{<i>MeActin</i> gene}) _control [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0177621#pone.0177621.ref037" target="_blank">37</a>]. Ct of the formula represent mean Ct values of three repeats from three independent qRT-PCR assays. The heat map was generated based on the log₂ (relative expression values) with MeV software. Red indicates high expression and white indicates low expression. D, drought stress; O, osmotic stress; S, salt stress. Asterisk (*) on the right corner of number indicate a significant difference at <i>P</i> < 0.05 (Student’s <i>t</i>-test) and absolute log₂ (relative expression values) > 1 compared with non-treated control. NA denote the expression was too weak to detect.