The Dynamic Effects of Transposon Insertions on AuxRP1 Transcription During Vegetative Development in Zea mays

Abstract

The AuxRP1 gene ( Zm00001eb053610 ) is involved in the auxin signaling pathway and stalk rot resistance in Zea mays . In this study, we examined four transposon insertion lines (UFMu-03429, UFMu-00414, UFMu-08200, and AcDs-00676) targeting AuxRP1 . Transcription of AuxRP1 of the insertion lines either decreased or remained unchanged at the juvenile (V3) stage but increased significantly at the transition/adult (V6) stage. We also analyzed its upstream gene TSB2C and downstream gene Yucca2 . Our results show that transposon insertions can induce stage-specific changes in gene expression that affect related biosynthetic pathways.

Figure 1. Relative expressions of the AuxRP1 and its pathway genes in transposon insertion lines

A. Gene model of AuxRP1 ( Zm00001eb053610 ) showing exons annotated in Zm00001eb053610_T001 and transposon insertion sites for UFMu-03429 (flanking region), UFMu-00414 (exon 3), and UFMu-08200 and AcDs-00676 (exon 7). The orange arrows mark the positions of primers used in qRT-PCR for AuxRP1. B–D. Average relative transcript levels of AuxRP1 , TSB2C , and Yucca2 , respectively, in transposon insertion lines compared to wild-type (W22) plants at the juvenile stage (V3; leaves 3/4/5) and transition/adult stages (V6; leaves 8/10). Asterisks indicate statistical significance ( p < 0.05 as *, p < 0.01 as **, and p < 0.001 as ***) from the non-parametric Mann-Whitney U test on ∆Ct values (Chen et al., 2006). All data are based on two to three biological replicates and three technical replicates. Error bars indicate ± standard errors.