Onset of Phloem Export from Senescent Petals of Daylily.

摘要: During senescence, petals of attached daylily (Hemerocallis hybrid cv Cradle Song) flowers lost 95% sugar and 65% dry weight over the first 24 h, with 30% loss coming from nonsugar components. Detaching did not delay but halted carbohydrate amino acid, suggesting that in intact state was due to phloem export. Petal autolysis occurred mainly interveinal parenchyma, causing vascular strands begin separating petal mass. Such still stained tetrazolium accumulated sucrose, indicating a retained viability. Their sucrose accumulation rates were high comparison those other plant tissues, product sucrose. Sucrose synthesis took place senescent petal, principal exudate, whereas hydroxyproline glutamine main transport acids. [14C]Sucrose applied rapidly translocated parts plant, particularly developing flower buds. Thus, onset export allowed most soluble acid senescing be retrieved by plant. Additional salvaged material came proteins possibly structural carbohydrate. Over 12-h period, switched acting as strong sink during expansion become source senescence. This rapid reversal offers potential for studies.