Kaufman L S, Roberts L L, Briggs W R, Thompson W F
Carnegie Institution of Washington, Department of Plant Biology, Stanford, California 94305.
Plant Physiol. 1986 Aug;81(4):1033-8. doi: 10.1104/pp.81.4.1033.
We have examined the time course for accumulation of each of 12 different nuclear gene transcripts in pea buds after irradiating dark grown seedlings with a single pulse low fluence red light (10(3) micromoles per square meter delivered in 100 seconds). The 12 time courses can be grouped into four general classes. Six transcripts (including RNAs coding for the chlorophyll a/b binding protein and ribulose-1,5-bisphosphate carboxylase) accumulate at a linear rate during 24 hours in darkness following the light pulse. Two transcripts increase rapidly at first but then reach a plateau after 3 hours and remain at that level for the next 21 hours. Another two transcripts exhibit a prolonged lag period before beginning to accumulate, and do not reach significant accumulation rates until 12 to 16 hours after the red light pulse. One transcript appears to undergo a transient increase in abundance in response to red light, but this is superimposed on a background of slowly increasing abundance of this RNA in control plants. This response, unlike all the others, exhibits reciprocity failure in experiments in which the same fluence of light is given over periods ranging between 50 and 4000 seconds.We have also examined the kinetics with which each of these 12 responses escapes from phytochrome-far-red absorbing form control by attempting to reverse the induction with far-red light given at various times after the red light pulse. Again, several different patterns are apparent for the different transcripts. The time at which far red reversibility first begins to be lost, the rate at which it is lost, and the final extent of reversibility remaining after 7 hours in the dark all differ for different transcripts. In addition, we have observed that some responses retain virtually complete photoreversibility for at least 7 hours. In some cases, a comparison of the time course and escape kinetic data indicates that relatively rapid turnover of the RNA must occur. It is not clear whether or not the rate of turnover is influenced by phytochrome.
我们研究了用单脉冲低通量红光（100秒内照射10³微摩尔每平方米）照射黑暗中生长的豌豆幼苗后，豌豆芽中12种不同核基因转录本积累的时间进程。这12个时间进程可分为四大类。六种转录本（包括编码叶绿素a/b结合蛋白和核酮糖-1,5-二磷酸羧化酶的RNA）在光脉冲后的24小时黑暗中以线性速率积累。两种转录本起初迅速增加，但在3小时后达到平稳期，并在接下来的21小时保持在该水平。另外两种转录本在开始积累前有较长的延迟期，直到红光脉冲后12至16小时才达到显著的积累速率。一种转录本似乎因红光而丰度短暂增加，但这叠加在对照植物中该RNA丰度缓慢增加的背景上。与所有其他反应不同，在50至4000秒不同时间段给予相同光通量的实验中，这种反应表现出互易性失效。我们还通过尝试在红光脉冲后的不同时间用远红光逆转诱导，研究了这12种反应从光敏色素远红光吸收形式控制中逃逸的动力学。同样，不同转录本有几种不同的模式。远红光可逆性首次开始丧失的时间、丧失的速率以及在黑暗中7小时后剩余的最终可逆程度，不同转录本均不同。此外，我们观察到一些反应在至少7小时内几乎保持完全的光可逆性。在某些情况下，时间进程和逃逸动力学数据的比较表明，RNA必须发生相对快速的周转。周转速率是否受光敏色素影响尚不清楚。
