Shinkle J R
Carnegie Institution of Washington, Stanford, California 94305.
Plant Physiol. 1986 Jun;81(2):533-7. doi: 10.1104/pp.81.2.533.
The far-red reversibility of the phytochrome-controlled stimulation of elongation of coleoptile sections by low fluence red light has been characterized in subapical coleoptile sections from dark-grown Avena sativa L., cv Lodi seedlings. The fluence dependence of the far-red reversal was the same whether or not the very low fluence response is also expressed. The capacity of far-red light to reverse the red light-induced response began to decline if the far-red light was given more than 90 minutes after the red irradiation. Escape was complete if the far red irradiation was given more than 240 minutes after the red irradiation. Sections consisting of both mesocotyl and coleoptile tissue from dark-grown Avena seedlings were found to have physiological regulation of the very low fluence response by indole 3-acetic acid and low external pH similar to that seen for sections consisting entirely of coleoptile tissue. The fluence-dependence of the red light-induced inhibition of mesocotyl elongation was studied in mesocotyl sections from dark grown Zea mays L. hybrid T-929 seedlings. Ten micromolar indole 3-acetic acid stimulates the control elongation of the sections, while at the same time increasing the sensitivity of the tissue for the light-induced inhibition of growth by a factor of 100.
在黑暗生长的燕麦（Avena sativa L.，品种Lodi）幼苗的根尖下胚轴切段中，已对低通量红光通过光敏色素控制的刺激下胚轴切段伸长的远红光可逆性进行了表征。无论是否也表达极低通量反应，远红光逆转的通量依赖性都是相同的。如果在红光照射后90分钟以上给予远红光，远红光逆转红光诱导反应的能力开始下降。如果在红光照射后240分钟以上给予远红光，逃逸则完全完成。发现由黑暗生长的燕麦幼苗的中胚轴和胚芽鞘组织组成的切段，对极低通量反应具有与完全由胚芽鞘组织组成的切段类似的吲哚-3-乙酸和低外部pH值的生理调节。在黑暗生长的玉米（Zea mays L.，杂交种T-929）幼苗的中胚轴切段中，研究了红光诱导的中胚轴伸长抑制的通量依赖性。10微摩尔的吲哚-3-乙酸刺激切段的对照伸长，同时将组织对光诱导生长抑制的敏感性提高100倍。
