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ARS Home » Research » Publications at this Location » Publication #107487
Title: OXYGEN METABOLISM IN PLANT/BACTERIA INTERACTIONS: CHARACTERIZATION OF THE OXYGEN UPTAKE RESPONSE OF POTATO SUSPENSION CELLS

Author
item Baker, Con
item Orlandi, Elizabeth
item Deahl, Kenneth

Submitted to: Physiological and Molecular Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: The goal of this work is to improve disease resistance in potatoes. There are several bacterial diseases of potato which cause significant damage in the field. This study for the first time reports a very rapid physiological response from potato which indicates how quickly the plant detects bacteria. The faster the detection, the faster the triggering of resistance and the greater the chance of survival. Specifically the response is an increase in oxygen uptake which also indicates that many intracellular biochemical pathways have been triggered. This will be a very useful tool in elucidating the mechanism by which potatoes detect bacteria and turn on their resistance mechanisms. This work will benefit ARS and scientists by providing a quantitative means to compare and improve detection/recognition mechanisms in potato and lead to less yield loss to disease.

Technical Abstract: Within minutes after the addition of heat-killed bacteria, potato suspension cells responded with a rapid increase in oxygen uptake. The elicited cells continued to utilize oxygen at a steady but accelerated rate for several minutes before beginning a slow increase over the remaining few hours of the monitoring period. Calculation of the total oxygen consumption by the plant cells indicated that only a small fraction of the increased oxygen uptake was due to the concomitant production of reactive oxygen species. Pretreatment of cells with the NAD(P)H inhibitor, DPI, prohibited the production of reactive oxygen, and inhibited the total oxygen uptake response by approximately 60 %. The protein kinase inhibitor, K-252, inhibited the oxygen uptake response by more than 90%, suggesting the involvement of protein phosphorylation in the oxygen uptake response. The alternate oxidase inhibitor, SHAM, significantly inhibited the elicited oxygen uptake increase while a combination of SHAM and KCN almost completely blocked both the basal oxygen uptake and the elicited response. The data indicate that mitochondrial respiration and, in particular, the alternate oxidase, play a significant role in the elicited oxygen uptake response of potato cells.