Expression of PLDs in response to various stresses.
(A) RNA blotting of PLDα1 and PLDγ transcripts in Arabidopsis leaves exposed to different stress treatments. Arabidopsis Col-0 (3–week old) leaves were detached and floated on water without or with indicated concentrations of chemicals, 1% NaCl, 0.6 M mannitol, 0.2 mM AlCl3, 0.2 mM CdCl2, 2 mM H2O2, 0.1 mM salicylic acid (SA), 0.1 mM methyl salicylate (MeSA), 0.1 mM abscisic acid (ABA), or 0.1 mM methyl jasmonate (MeJA) in a growth chamber at 22°C. Leaves were collected at the indicated times for RNA extraction and northern blotting with [α-32P]-labeled PLDα1 or PLDγ1 full-length cDNA as a probe. (B) RNA blotting of PLDγs using the coding region of PLDγ1 (upper panel) or PLDγ2-specific 5′-UTR (lower panel) under Al stress. Two week-old wild-type seedlings grown in ½ MS medium were treated with 100 µM AlCl3, and roots of seedlings were collected at the indicated time for RNA extraction. [α-32P]-Labeled PLDγ1 cDNA or PLDγ2- specific 5′-UTR was used as a probe for northern blotting. EtBr-stained ribosomal RNA was used as a loading control.