Abstract
Auxin [α-naphthaleneacetic acid (NAA) or indole-3-acetic acid] can induce the expression of lipoxygenases (LOXs) in cultured immature zygotic embryo cotyledons of soybean [Glycine max. (L.) Merr]. These auxin-induced LOXs are different from those normally expressed in seeds but have the same isoelectric points (pI) as those found in seedlings. The pIs of the two seedling LOXs were determined to be 5.09 and 5.23. One of the auxin-induced LOXs has the same pI (5.09) and molecular mass (94 kDa) as seedling LOX4. The partial amino acid sequences from the purified NAA-induced pI-5.09 LOX are identical to those of LOX4. RNA protection assays showed that NAA induces the expression of LOX4 and LOX5 mRNAs in cultured embryo cotyledons where they are not normally expressed. Soybean genotypes with a polymorphic variant of LOX4 in hypocotyls showed the same variation as NAA-induced LOXs in the embryo cotyledons. These results demonstrate that the NAA-induced pI-5.09 LOX is seedling LOX4 and also suggest that auxin might be directly or indirectly involved in seedling LOX expression during seed germination.
| Original language | English |
|---|---|
| Pages (from-to) | 85-91 |
| Number of pages | 7 |
| Journal | Plant Cell Reports |
| Volume | 20 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2001 |
Bibliographical note
Funding Information:Acknowledgements We thank Ms Yuan Sun for excellent assistance in the culture of soybean cotyledons, Dr Carol Beach for the amino acid sequence analysis, and Dr Wennuan Liu for help with the culture of soybean cotyledons. We also thank Dr J. Polacco for LOX4 and LOX5 cDNAs and Drs K. Kitamura and N. Nielsen for the soybean seed LOX mutants. This work was supported by USDA grant no. 9701487, the THRI and the Kentucky Agricultural Experiment Station and published as paper no. 96-06-065.
Keywords
- Auxin
- Cotyledon
- Glycine max
- Immature zygotic embryo
- Lipoxygenase
ASJC Scopus subject areas
- Agronomy and Crop Science
- Plant Science