| Autor: |
Kumar GN; Postharvest Physiology and Biochemistry Laboratory, Department of Horticulture and Landscape Architecture, Washington State University, Pullman, WA 99164-6414, USA., Iyer S, Knowles NR |
| Jazyk: |
angličtina |
| Zdroj: |
Planta [Planta] 2007 Dec; Vol. 227 (1), pp. 25-36. Date of Electronic Publication: 2007 Jul 26. |
| DOI: |
10.1007/s00425-007-0589-9 |
| Abstrakt: |
During 30-months of storage at 4 degrees C, potato (Solanum tuberosum L.) tubers progressively lose the ability to produce superoxide in response to wounding, resist microbial infection, and develop a suberized wound periderm. Using differentially aged tubers, we demonstrate that Strboh A is responsible for the wound-induced oxidative burst in potato and aging attenuates its expression. In vivo superoxide production and NADPH oxidase (NOX) activity from 1-month-old tubers increased to a maximum 18-24 h after wounding and then decreased to barely detectable levels by 72 h. Wounding also induced a 68% increase in microsomal protein within 18 h. These wound-induced responses were lost over a 25- to 30-month storage period. Superoxide production and NOX activity were inhibited by diphenylene iodonium chloride, a specific inhibitor of NOX, which in turn effectively inhibited wound-healing and increased susceptibility to microbial infection and decay in 1-month-old tubers. Wound-induced superoxide production was also inhibited by EGTA-mediated destabilization of membranes. The ability to restore superoxide production to EGTA-treated tissue with Ca(+2) declined with advancing tuber age, likely a consequence of age-related changes in membrane architecture. Of the five homologues of NOX (Strboh A-D and F), wounding induced the expression of Strboh A in 6-month-old tubers but this response was absent in tubers stored for 25-30 months. Strboh A thus mediates the initial burst of superoxide in response to wounding of potato tubers; loss of its expression increases the susceptibility to microbial infection and contributes to the age-induced loss of wound-healing ability. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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