Changes in the composition of xylem sap during development of the spadix of skunk cabbage (Symplocarpus foetidus).
The spadix of skunk cabbage, Symplocarpus foetidus, is thermogenic and maintains an internal temperature of around 20 degrees C even when the ambient air temperature drops below freezing. This homeothermic heat production is observed only during the stigma stage, and thereafter ceases at the male stage when pollen is shed. To clarify the regulatory mechanism by which the stigma stage-specific heat production occurs in the spadix, sugars, organic acids, and amino acids in xylem sap were analyzed and compared with those of post-thermogenic plants. Interestingly, no significant difference was observed in the total volume of xylem sap per fresh weight of the spadix between thermogenic (31.2+/-24.7 microl h(-1) g(-1)) and post-thermogenic (50.5+/-30.4 microl h(-1) g(-1)) plants. However, concentrations of sugars (sucrose, glucose, and fructose), organic acids (malate and succinate), and amino acids (Asp, Asn, Glu, Gln, Gly, and Ala) in xylem sap decreased remarkably in post-thermogenic plants. Our results indicate that the composition of the xylem sap differs during the development of the spadix of S. foetidus.
Cryobiosystem Research Center, Faculty of Agriculture, Iwate University, Morioka, Japan.
Yoshihiko
Y
Onda
Kikukatsu
K
Ito
D000596:Amino Acids / Q000032:analysis; D029064:Araceae / Q000254:growth & development* / Q000378:metabolism*; D019343:Citric Acid / Q000032:analysis; D005632:Fructose / Q000032:analysis; D005947:Glucose / Q000032:analysis; D006358:Hot Temperature; D008293:Malates / Q000032:analysis; D035261:Plant Components, Aerial / Q000254:growth & development / Q000378:metabolism*; D019802:Succinic Acid / Q000032:analysis; D013395:Sucrose / Q000032:analysis
D000596:Amino Acids; D008293:Malates; D019343:Citric Acid; D005632:Fructose; D013395:Sucrose; C030298:malic acid; D019802:Succinic Acid; D005947:Glucose