A circadian and an ultradian rhythm are both evident in root growth of rice
A circadian and an ultradian rhythm are both evident in root growth of rice
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DOI：
10.1016/j.jplph.2011.06.005
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发表时间：
2011-11-15
影响因子：
4.3
通讯作者：
Matsushita, Naofumi
中科院分区：
文献类型：
--
作者：
Iijima, Morio;Matsushita, Naofumi
本文提出了水稻根伸长生长同时存在昼夜节律和超长节律的证据。利用与计算机相连的CCD摄像机，在微弱的绿光下记录水稻(Oryza Sativa)的根伸长。设置了4种处理条件来研究内源节律的存在：28℃恒温连续暗(28DO)；28℃恒温交替明暗(28LD)；33℃恒温连续暗(33DD)；以及昼夜温度变化和明暗交替(DT-LD)。由此得到的光谱密度表明，4个处理均存在20.4~25.2 h(昼夜周期)和2.0~6.0 h(超常周期)的周期。较短的超长周期可归因于根的旋转生长和/或粘液分泌。所有重复数据的平均值表明，最高的功率谱密度(PSD)对应于根的生长节律，28个DD、28个LD和33个DD的周期分别为22.9、23.7和2.1h。每个数据集的PSD累积表明，28个DD和33个DD处理的周期性相似。我们认为，水稻根部伸长存在23h的昼夜节律和2h的超常节律。此外，28个LD和DT-LD处理的根伸长速率白天分别是夜间的1.08倍和1.44倍。(C)2011年爱思唯尔股份有限公司。版权所有。
This paper presents evidence for the existence of both a circadian and an ultradian rhythm in the elongation growth of rice roots. Root elongation of rice (Oryza sativa) was recorded under dim green light by using a CCD camera connected to a computer. Four treatment conditions were set-up to investigate the existence of endogenous rhythms: 28 degrees C constant temperature and continuous dark (28 DO); 28 degrees C constant temperature and alternating light and dark (28 LD); 33 degrees C constant temperature and continuous dark (33 DD); and diurnal temperature change and alternating light and dark (DT-LD). The resulting spectral densities suggested the existence of periodicities of 20.4-25.2 h (circadian cycles) and 2.0-6.0 h (ultradian cycles) in each of the 4 treatments. The shorter ultradian cycles can be attributed to circumnutational growth of roots and/or to mucilage exudation. The average values across all the replicate data showed that the highest power spectral densities (PSDs) corresponded to root growth rhythms with periods of 22.9, 23.7, and 2.1 h for the 28 DD, 28 LD, and 33 DD treatments, respectively. Accumulation of PSD for each data set indicated that the periodicity was similar in both the 28 DD and 33 DD treatments. We conclude that a 23-h circadian and a 2-h ultradian rhythmicity exist in rice root elongation. Moreover, root elongation rates during the day were 1.08 and 1.44 times faster than those during the night for the 28 LD and DT-LD treatments, respectively. (C) 2011 Elsevier GmbH. All rights reserved.