Genome sequence of aod2 mutant derived from Arabidopsis thaliana Bu-5. Arabidopsis thaliana

Acquired osmotolerance induced after salt stress is widespread across Arabidopsis thaliana (Arabidopsis) accessions including Bu-5. However, it remains unclear how the osmotolerance is established. We isolated an acquired osmotolerance-defective mutant 2 (aod2) from ion beam-mutagenized M2 population of Bu-5. The aod2 was impaired not only in acquired osmotolerance, but also in osmo-shock, salt-shock and long-term (L-) heat tolerances compared to WT and displayed abnormal morphology, including wrinkled small leaves and zigzag stems. We found that the 439 kbp region of chromosome 4 was translocated into the causal locus for the osmosensitive phenotype of aod2 on chromosome 3. The causal gene of aod2 was identical to ECERIFERUM 10 (CER10) encoding an enoyl-CoA reductase involved in very-long-chain fatty acids (VLCFA) elongation reactions required for cuticular wax, storage lipid, and sphingolipid metabolism.