Wound-induced phenolic accumulation and browning in lettuce (Lactuca sativa L.) leaf tissue is reduced by exposure to n-alcohols
نویسندگان
چکیده
A wound signal originates at the site of injury in lettuce (Lactuca sativa L.) leaf tissue and propagates into adjacent tissue where it induces a number of physiological responses which include increased phenolic metabolism with the de novo synthesis of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), the synthesis and accumulation of soluble phenolic compounds (e.g., chlorogenic acid), and subsequent tissue browning. Exposing excised mid-rib leaf tissue to vapors (20 mol/(g FW)) or aqueous solutions (100 mM) of n-alcohols inhibited this wound-induced tissue browning by 40 and 60%, respectively. Effectiveness of the alcohol increased linearly from ethanol to the 7-carbon heptanol, and then was lost for the longer n-alcohols 1-octanol and 1-nonanol. The 2and 3-isomers of the effective alcohols did not significantly reduce wound-induced phenolic accumulation at optimal 1-alcohol concentrations, but significant reductions did occur at much higher concentrations (100 mol/(g FW)) of the 2-, a i i n s ©
منابع مشابه
Heat shock treatments delay the increase in wound-induced phenylalanine ammonia-lyase activity by altering its expression, not its induction in Romaine lettuce (Lactuca sativa) tissue
Wounding lettuce (Lactuca sativa L., var. Longifolia) leaves induced an eight-fold increase in the activity of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), and the subsequent accumulation of phenolic compounds and tissue browning at 10 C. PAL is a key enzyme in the synthesis of phenolic compounds. A PAL cDNA was previously isolated by reverse-transcription PCR using total RNA from wounded let...
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