Expression of three osmotin-like protein genes in response to osmotic stress and fungal infection in potato.
We have characterized three cDNAs encoding osmotin-like proteins from potato (Solanum commersonii) cell cultures. These cDNAs (pA13, pA35, and pA81) have extensive nucleotide identity in the coding regions but low homology in the 3' non-coding sequences, and may encode three isoforms of potato pathogenesis-related (PR) type 5 proteins. Using gene-specific probes, RNA gel blot analyses showed constitutive accumulation of osmotin-like protein mRNAs in cell cultures, leaves, stems, roots and flowers, with high abundance in the roots and mature flowers. Treatments with abscisic acid (ABA), low temperature, and NaCl increased the accumulation of all three mRNAs in S. commersonii cell cultures and plants grown in vitro. Salicylic acid (SA), and wounding resulted in a moderate increase in the levels of pA13 and pA81 but not pA35 mRNAs. Infection with the fungus Phytophthora infestans activated strong and non-systemic expression of all three osmotin-like protein genes. The accumulation of osmotin-like proteins, however, was detected only in P. infestans-infected tissues but not in plants treated with ABA, SA, NaCl, low temperature, or wounding.
Zhu
B
B
Department of Horticultural Sciences, University of Minnesota, St. Paul 55108, USA.
Chen
T H
TH
Li
P H
PH
D000220:Adaptation, Biological / Q000235:genetics; D000595:Amino Acid Sequence; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D017343:Genes, Plant / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000235:genetics*; D015151:Immunoblotting; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010812:Physical Stimulation; D010838:Phytophthora / Q000472:pathogenicity; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics*; D016372:RNA, Antisense; D012333:RNA, Messenger / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics*; D013268:Stimulation, Chemical; D014018:Tissue Distribution
D018076:DNA, Complementary; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; C073139:osmotin protein, Nicotiana tabacum