Kende H, Hanson A D
Michigan State University/Energy Research and Development Administration Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824.
Plant Physiol. 1976 Apr;57(4):523-7. doi: 10.1104/pp.57.4.523.
An excised tissue system consisting of corolla rib segments was developed to study the relationship between senescence and ethylene production in morning-glory flowers (Ipomoea tricolor). Such segments, isolated 1 or 2 days (day -1 or day -2) before flower opening (day 0) passed through the same developmental phases as did the corresponding tissues of the intact organ. When excised on day -1 and incubated overnight, the rib segments turned from purple to blue and changed from a slightly curled to a flat configuration. On day 0, these segments rolled up during the afternoon and turned purple again, as did the ribs of an intact corolla; the rolling up coincided with an increased rate of ethylene production. Premature rolling up and associated ethylene evolution were induced by ethylene or propylene treatment. When segments were excised on day -2 and incubated overnight, there were no changes in color or shape; during day -1, no spontaneous rolling up and little ethylene evolution occurred. Application of ethylene or propylene to these immature segments elicited rolling up but did not stimulate endogenous ethylene production.Overnight treatment of segments cut on day -1 with 10(-6)m benzyladenine markedly retarded spontaneous rolling up and ethylene evolution, although the response to applied ethylene was only slightly slowed. Overnight treatment of segments cut on day -1 with the ethoxy analog of rhizobitoxine (10(-5) to 10(-4)m) resulted in almost complete (>99%) inhibition of both spontaneous and propylene-induced ethylene evolution. Although spontaneous rolling up was delayed, it was not abolished, and ethylene-induced rolling up was almost unaffected.These data indicate that an ethylene-generating system develops as an integral part of the aging process in flower tissue. Ethylene hastens aging of the flower, but may not play an obligatory role in flower senescence.
为了研究牵牛花（三色牵牛）衰老与乙烯生成之间的关系，开发了一种由花冠肋段组成的离体组织系统。这些在花朵开放前1天或2天（-1天或-2天）分离的片段，与完整器官的相应组织经历相同的发育阶段。-1天切下并孵育过夜后，肋段从紫色变为蓝色，从轻微卷曲变为扁平状。在0天，这些片段在下午卷曲起来并再次变为紫色，完整花冠的肋条也是如此；卷曲与乙烯生成速率增加同时发生。乙烯或丙烯处理诱导了过早卷曲和相关的乙烯释放。当在-2天切下片段并孵育过夜时，颜色和形状没有变化；在-1天，没有自发卷曲，乙烯释放很少。对这些未成熟片段施加乙烯或丙烯会引起卷曲，但不会刺激内源性乙烯生成。用10^(-6)m苄基腺嘌呤对-1天切下的片段进行过夜处理，显著延缓了自发卷曲和乙烯释放，尽管对施加乙烯的反应仅略有减慢。用根瘤菌素的乙氧基类似物（10^(-5)至10^(-4)m）对-1天切下的片段进行过夜处理，几乎完全（>99%）抑制了自发和丙烯诱导的乙烯释放。虽然自发卷曲被延迟，但并未消除，乙烯诱导的卷曲几乎未受影响。这些数据表明，乙烯生成系统是花组织衰老过程的一个组成部分。乙烯加速花朵衰老，但可能在花朵衰老中不发挥必不可少的作用。
