Hamner, Melissa , Shinkle, James .
Spinach shows no cross protection between drought and UV-B stresses.
Many abiotic stresses induce antioxidant responses. Previous studies have observed that contemporaneous application of two different stresses can provide cross protection to radical oxygen species. As an agriculturally significant crop, understanding this stress induced antioxidant response is important both to production and nutritional value of spinach. In this study, we observed the antioxidant and cross protection responses to drought and UV-B stress in spinach. Stresses were applied for nine days by exposing plants to 1.84 Wm-2 of UV-B (280-320 nm) for four hours a day or by withholding water. Four different stress regimes were used: only UV-B, only drought, UV-B then drought or drought then UV-B stress. Leaf disc samples were collected at the end of the stress period. Leaf discs were analyzed for soluble antioxidant content by measuring the dissipation of the stable free-radical DMPD. A lipid peroxidation assay was used to determine the amount of damage induced by radical oxygen species. A significant increase in antioxidants was observed in plant under drought and UV-B then drought stress. However, no difference was seen between plants exposed to a single stress and those exposes to both stresses. A significant decrease in damage caused by radical oxygen species to lipids was observed in plants that received UV-B and drought then UV-B stress. Again, no cross protection advantage was seen. These results indicate that different types of abiotic stress induce independent protective responses.
Log in to add this item to your schedule
1 - Trinity University, Biology, One Trinity Place, San Antonio, TX, 78212, USA
2 - Trinity University, Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM