Thursday, November 8, 2007 - 9:15 AM

Effects of Waterlogging on Mitochondrial Oxidative Injury and Manganese Superoxide Dismutase in Roots of Kentucky Bluegrass.

Yiwei Jiang1, Kehua Wang2, and Jeffrey Volenec1. (1) Agronomy Dept, Purdue University-Agronomy Dept., Purdue University, 915 W. State Street, West Lafayette, IN 47907, (2) Agronomy Dept., Purdue University, 915 W. State Street, West Lafayette, IN 47907

Oxidative injury occurs in root mitochondria in response to waterlogging. The objective of this project was to investigate effects of waterlogging on mitochondrial oxidative injury and mitochondrial manganese superoxide dismutase (Mn-SOD) in roots of Kentucky bluegrass (Poa pratensis L.). Two cultivars of Moonlight (waterlogging tolerant) and Kenblue (waterlogging sensitive) were subjected to 1, 3 and 7 d of waterlogging. Mitochondrial superoxide and hydrogen peroxide concentrations did not change for both cultivars under waterlogging conditions. At 7 d of waterlogging, mitochondrial lipid peroxidation remained unchanged in Moonlight but increased in Kenblue, and mitochondrial total SOD activity increased in both cultivars. Immunoblots showed an increased intensity of mitochondrial Mn-SOD polypeptide (25 kDa) at 7 d of waterlogging, particularly in Kenblue, while RT-PCR indicated that the transcript abundance for mitochondrial Mn-SOD decreased in both cultivars. The results suggested that the tolerant grass had less oxidative injury than the intolerant grass in response to the extended waterlogging condition, and regulation of mitochondrial Mn-SOD activity may be occurring at several levels in the roots of Kentucky bluegrass.