Suttle JC
United States Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, P.O. Box 5677, State University Station, Fargo, North Dakota 58105-5677, USA.
Plant Physiol. 1998 Nov;118(3):843-8. doi: 10.1104/pp.118.3.843.
Potato (Solanum tuberosum L.) single-node explants undergoing in vitro tuberization produced detectable amounts of ethylene throughout tuber development, and the resulting microtubers were completely dormant (endodormant) for at least 12 to 15 weeks. The rate of ethylene production by tuberizing explants was highest during the initial 2 weeks of in vitro culture and declined thereafter. Continuous exposure of developing microtubers to the noncompetitive ethylene antagonist AgNO3 via the culture medium resulted in a dose-dependent increase in precocious sprouting. The effect of AgNO3 on the premature loss of microtuber endodormancy was observed after 3 weeks of culture. Similarly, continuous exposure of developing microtubers to the competitive ethylene antagonist 2, 5-norbornadiene (NBD) at concentrations of 2 mL/L (gas phase) or greater also resulted in a dose-dependent increase in premature sprouting. Exogenous ethylene reversed this response and inhibited the precocious sprouting of NBD-treated microtubers. NBD treatment was effective only when it was begun within 7 d of the start of in vitro explant culture. These results indicate that endogenous ethylene is essential for the full expression of potato microtuber endodormancy, and that its involvement may be restricted to the initial period of endodormancy development.
在离体块茎形成过程中，马铃薯（Solanum tuberosum L.）单节外植体在整个块茎发育过程中产生可检测量的乙烯，并且所形成的微型块茎至少12至15周完全处于休眠状态（内休眠）。在离体培养的最初2周内，进行块茎形成的外植体产生乙烯的速率最高，此后下降。通过培养基使发育中的微型块茎持续暴露于非竞争性乙烯拮抗剂硝酸银（AgNO₃），导致早熟发芽呈剂量依赖性增加。培养3周后观察到AgNO₃对微型块茎内休眠过早丧失的影响。同样，将发育中的微型块茎持续暴露于浓度为2 mL/L（气相）或更高的竞争性乙烯拮抗剂2,5-降冰片二烯（NBD），也导致早熟发芽呈剂量依赖性增加。外源乙烯逆转了这种反应，并抑制了经NBD处理的微型块茎的早熟发芽。NBD处理仅在离体外植体培养开始后7天内开始时才有效。这些结果表明，内源乙烯对于马铃薯微型块茎内休眠的充分表达至关重要，并且其作用可能仅限于内休眠发育的初始阶段。
