FIGURE 2.

Manganese toxicity reduces auxin accumulation in root tips. Image of GUS staining (A) and the relative GUS activity (B) of 5-day-old DR5:GUS seedlings exposed to 4 mM MnCl₂ for 6 h and 1 day. YFP fluorescence (C) and quantification of the DII-VENUS fluorescence intensities (D) in the roots of 5-day-old DII-VENUS seedlings exposed to 4 mM MnCl₂ for 6 h-2 days. (E) Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis of the expression of IAA biosynthesis-related genes in wild-type col-0 seedlings treated with or without 4 mM MnCl₂ for 2 days. The expression levels of the indicated genes in the untreated roots were set to 1. The error bars represent the ±SD. Different letters indicate significantly different values (P < 0.05 by Tukey’s test). ^∗∗P-value < 0.01.