Figure 1.

Arabidopsis LSM1 Proteins Accumulate in Response to Low Temperature and Localize to P-Bodies.

(A) Expression of LSM1A and LSM1B in 2-week-old Col-0 plants exposed for the indicated hours (h) or days (d) to 4°C. Levels, determined by qPCR, are represented as relative to their corresponding values at 0 h. Error bars indicate the sd of the mean (n ≥ 3). In all cases, differences between cold-treated and control (0 h) plants were significant (P ≤ 0.0001), as determined by ANOVA test.

(B) Immunoblots showing levels of LSM1A-GFP and LSM1B-GFP in 2-week-old transgenic Arabidopsis plants exposed for the indicated times to 4°C. A lane with Col-0 plants was added in the immunoblot as a negative control. Coomassie staining of the large subunit of Rubisco was used as a loading control.

(C) Subcellular localization of LSM1A-GFP and LSM1B-GFP in root tip cells from 6-d-old transgenic Arabidopsis seedlings grown under control conditions (20°C) or exposed for 24 h to 4°C in the presence or absence of cycloheximide (CHX). Bars = 20 µm.

(D) Colocalization of LSM1A-GFP and LSM1B-GFP with RFP-DCP1 in root tip cells from 6-d-old transgenic Arabidopsis seedlings exposed for 24 h to 4°C. Bars = 20 µm.

(E) Subcellular localization of GFP-DCP2 and GFP-VCS in root tip cells from 6-d-old Col-0 and lsm1a lsm1b Arabidopsis seedlings grown under control conditions and subsequently exposed for 24 h to 4°C. Bars = 20 µm.