ARS | Publication request: CHANGES IN CIS-ZEATIN/CIS-ZEATIN RIBOSIDE LEVELS AND BIOLOGICAL ACTIVITIES DURING POSTHARVEST STORAGE OF POTATO TUBERS

Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 1997
Publication Date: N/A

Technical Abstract: Endogenous levels of cis-Zeatin (cZ) and it's riboside (cZR) were monitored throughout postharvest storage in relation to potato tuber bud endodormancy. Potato bud extracts were fractionated by HPLC and cZ(R) levels were quantified using a monoclonal-based ELISA. Both cZ and cZR were detected in extracts prepared from both dormant and nondormant buds in levels ranging from 5-23 and 0-4 pmol/gFW for cZ and cZR (respectively). A transient, four-fold increase in cZ levels occurred prior to dormancy termination. Endogenous levels of cZR exhibited a similar, albeit reduced, pattern of change. During the initial period of postharvest storage, injection of either cZR or tZR had no effect on tuber dormancy. Following this period of complete insensitivity, stored tubers exhibited a time and concentration-dependent increase in cytokinin sensitivity. Throughout the postharvest storage period, the efficacy of cZR equaled that of tZR. The possible isomerization of cZ to tZ following injection is currently being investigated. The possible role of cZ(R) in potato tuber endodormancy regulation will be discussed.