Gravitropism in lateral roots of Arabidopsis pgm-1 mutants is indistinguishable from that of wild-type

Abstract

The majority of understanding of root gravity responses comes from the study of primary roots, even though lateral roots make a far greater contribution to root system architecture. The focus of this report is the analysis of gravitropic responses in lateral roots of wild-type background and pgm-1 mutants. Despite the significant reduction in gravitropic response of primary roots of pgm-1 mutants, the lateral roots of this mutant demonstrate wild-type rates of gravitropism, suggesting a significant difference in gravity signal transduction between primary and lateral roots.

Figure 1

Gravitropic responses of Col-0 (squares) and pgm-1 (circles) lateral roots. Seedlings (10- to 12-d-old) were gravistimulated by 45° and images of entire root systems were captured and analyzed as described in the text. Each point represents the mean lateral root tip angle for the given time point (n = 397 for Col-0; n = 438 for pgm-1). Error bars represent standard error of the mean.