Figure 1.

Molecular and Physiological Characterization of alix-1 Mutants.

(A) Photographs of wild-type (WT), phr1, alix-1 phr1, and alix-1 PHR1 plants grown in Pi-deficient medium for 10 d.

(B) and (C) Histograms showing anthocyanin and Pi content in wild-type, phr1, alix-1 phr1, and alix-1 PHR1 plants. Seedlings were grown for 12 d in Pi-deficient medium for anthocyanin measurements (Abs 530 nm/g fresh weight; n = 8) and for 10 d in complete medium for Pi content analysis (μM/g fresh weight; n = 6). Error bars indicate standard deviations.

(D) RT-qPCR analysis of the expression of representative PSI genes in wild-type, phr1, alix-1 phr1, and alix-1 PHR1 seedlings grown under low Pi (−P; 30 µM Pi) and Pi-sufficient (+P; 500 µM Pi) conditions. ACTIN8 was used as a housekeeping reference gene. Expression levels are relative to Pi-rich-grown wild-type values, which were normalized to 1. Data represent the mean of three biological replicates with sd.

(E) Pictures of 28-d-old (up) and 49-d-old (down) wild-type, phr1, alix-1 phr1, and alix-1 PHR1 plants grown in soil. Bars = 1 cm.

*P < 0.05 (Student’s t test) with respect to the phr1 mutant in the same experimental conditions.