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Peptide transport by germinating barley embryos.
1Department of Botany, Science Laboratories, University of Durham, South Road, DH1 3LE, Durham, U.K..
Planta
|January 15, 2014
Summary
Germinating barley embryos actively transport intact glycylsarcosine, a peptidase-resistant dipeptide. This provides the first evidence of a dipeptide transport system facilitating nutrient movement from endosperm to embryo during germination.
Area of Science:
- Plant Physiology
- Molecular Biology
- Biochemistry
Background:
- Plant germination relies on nutrient mobilization from storage tissues.
- Peptidases break down proteins into amino acids for embryo uptake.
- The transport of intact dipeptides in plants remains largely uncharacterized.
Purpose of the Study:
- To investigate the transport of dipeptides in germinating barley embryos.
- To determine if glycylsarcosine is transported intact across the scutellum.
- To identify potential dipeptide transport systems in plants.
Main Methods:
- Using germinating embryos of Hordeum vulgare L., var. Maris Otter, Winter.
- Monitoring the accumulation of glycylsarcosine against a concentration gradient.
- Analyzing the integrity of glycylsarcosine post-transport.
Main Results:
- Glycylsarcosine, a dipeptide resistant to peptidase activity, was accumulated intact.
- Accumulation occurred against a concentration gradient, indicating active transport.
- This demonstrates the presence of a functional dipeptide transport system.
Conclusions:
- Hordeum vulgare embryos possess a dipeptide transport system.
- This system is crucial for transferring intact dipeptides from the endosperm to the embryo.
- This finding offers new insights into nutrient mobilization during plant germination.
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