Age-induced loss of wound-healing ability in potato tubers is partly regulated by ABA
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Wounding of potato (Solanum tuberosum L.) tubers induces the development of a suberized closing layer and wound periderm that resists desiccation and microbial invasion. Wound-healing ability declines with tuber age (storage period). The mechanism of loss in healing capacity with age is not known; however, upregulation of superoxide production, increased ABA biosynthesis and phenylalanine ammonia lyase (PAL) activity in response to wounding are processes critical to the development of a suberized closing layer and wound periderm. Therefore, the role of ABA in modulating the age-induced loss of wound-healing ability of tubers was examined. Non-wounded older tubers had 86% less ABA (dry matter basis) than younger tubers. PAL transcript increased in younger tubers within 24 h of wounding, but transcription was delayed by 5 days in older tubers. Wound-induced PAL activity increased more rapidly in younger than older tubers. ABA treatment increased PAL expression and activity in tissue from both ages of tubers and restored the 24 h transcription time line in older tubers. Moreover, ABA treatment of wounded older tubers enhanced their resistance to water vapor loss following a 6-day wound-healing period. Wound-induced accumulation of suberin poly(phenolic(s)) (SPP) and suberin poly(aliphatic(s)) (SPA) was measurably slower in older versus younger tubers. ABA treatment hastened SPP accumulation in older tubers to match that in younger tubers, but only enhanced SPA accumulations over the initial 4 days of healing. Age-induced loss of wound-healing ability is thus partly due to reduced ability to accumulate ABA and modulate the production of SPP through PAL in response to wounding and to dysfunction in the downstream signaling events that couple SPA biosynthesis and/or deposition to ABA. ABA treatment partly restored the healing ability of older tubers by enhancing the accumulation of SPP without restoring wound-induced superoxide forming ability to the level of younger tubers. The coupling of phenolic monomers into the poly(phenolic) domain of suberin was therefore not limited by the diminished wound-induced superoxide production of older tubers.
KeywordsSolanum tuberosum Wound healing Suberization Abscisic acid Tuber age Storage Phenylalanine ammonia lyase
Phenylalanine ammonia lyase
The financial support provided by grants from the USDA/ARS, USDA/CSREES, Washington State Potato Commission and WSU Agricultural Research Center to NRK is gratefully acknowledged. We thank Dr. Lee Hadwiger, Department of Plant Pathology, Washington State University, Pullman, WA, USA, for providing PAL antiserum. We thank Mr. Jon Neubauer and Ms. Linda Huckle (USDA-ARS, NCSL) for technical assistance in preparing samples and determining SPP and SPA ratings and for LC-MS-SIM determination of ABA content.
- Bernards MA, Susag LM, Bedgar DL, Anterola AM, Lewis NG (2000) Induced phenylpropanoid metabolism during suberization and lignification: a comparative analysis. J Plant Physiol 157:601–607Google Scholar
- Croteau R, Kutchan TM, Lewis NG (2000) Natural products (secondary metabolites). In: Buchanan BB, Gruissem W, Jones RL (eds) Biochemistry and molecular biology of plants. American Society of Plant Physiologists, Rockville, pp 1250–1318Google Scholar
- Hahlbrock K, Scheel D (1989) Physiology and molecular biology of phenyl propanoid metabolism. Ann Rev Plant Physiol Mol Biol 40: 347–369Google Scholar
- Kato M, Hayakawa Y, Hyodo H, Ikoma Y, Yano M (2000) Wound-induced ethylene synthesis and expression and formation of 1-amiocyclopropane-1-carboxylate (ACC) synthase, ACC oxidase, phenylalanine ammonia-lyase, and peroxidase in wounded mesocarp tissue of Cucurbita maxima. Plant Cell Physiol 41:440–447PubMedGoogle Scholar
- Pociecha E, Płażek A, Janowiak F, Waligórski P, Zwierzykowski Z (2009) Changes in abscisic acid, salicylic acid and phenylpropanoid concentrations during cold acclimation of androgenic forms of Festulolium (Festuca pratensis X Lolium multiflorum) in relation to resistance to pink snow mould (Microdochium nivale). Plant Breed 128:397–403CrossRefGoogle Scholar
- Tanaka Y, Uritani I (1976) Immunochemical studies on fluctuation of phenylalanine ammonia-lyase activity in sweet potato in response to cut injury. J Biochem 79:21Google Scholar
- Taylor MA, Wright F, Davies HV (1994) Characterisation of the cDNA clones of two beta-tubulin genes and their expression in the potato plant (Solanum tuberosum L.). J Plant Mol Biol 26:1013–1018Google Scholar
- Wang X, El Hadrami A, Adam LR, Daayf F (2008) Differential activation and suppression of potato defense responses by Phytophthora infestans isolates representing US-1 and US-8 genotypes. Plant Pathol 57:1026–1037Google Scholar
- Weeda SM (2010) Protein turnover in potato tubers during development, long-term storage, and plant establishment. PhD dissertation, Washington State University, Mt VernonGoogle Scholar