Systemic signalling of environmental cues in Arabidopsis leaves
Systemic signalling of environmental cues in Arabidopsis leaves
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DOI：
10.1093/jxb/erj033
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发表时间：
2006-01-01
影响因子：
6.9
通讯作者：
Quick, WP
中科院分区：
文献类型：
--
作者：
Coupe, SA;Palmer, BG;Quick, WP
光强度和大气二氧化碳分压是已知的调节气孔数量的两个环境信号。先前的研究表明，如果向成熟的拟南芥叶片提供升高的二氧化碳（750 ppm，而不是环境中的 370 ppm）或降低的光照水平（50 μ mol m(-2) s(-1)，而不是 250 μ mol m(-2) s(-1)），则未接受处理的年轻发育叶片会以气孔密度生长，就像它们暴露于处理一样。但据信在成熟叶子中产生并传递到发育中叶子的信号在很大程度上是未知的。正如预期的那样，经处理的成熟拟南芥叶片的光合速率在二氧化碳浓度升高时增加，而在遮荫时降低。同样，经过处理的成熟叶子中的糖（葡萄糖、果糖和蔗糖）水平在二氧化碳浓度升高的情况下增加，并在遮荫处理下降低。还测量了正在发育的叶子中的糖水平，发现即使它们没有接受遮荫或高二氧化碳处理，它们也反映了这一结果。为了研究这些处理对整体基因表达模式的影响，使用 Affymetrix、22K 和 ATH1 阵列进行转录组学分析。在成熟叶子接受环境对照处理、升高CO2处理或遮荫处理，或同时接受升高CO2和遮荫处理2、4、12、24、48或96小时后，从发育中的叶子中提取总RNA。该实验重复四次。还进行了另外两项实验，一项是为了比较和对比在升高的二氧化碳下生长的植物的基因表达，另一项是为了观察这些处理对成熟叶子的影响。对数据进行分析，未处理的带信号叶子中的 915 个基因被鉴定为表达水平受到遮荫处理的影响。然后将这些基因与成熟处理叶片中转录本丰度受到遮荫处理影响的基因（1181 个基因）以及先前从 yoda 突变体研究中鉴定出的 220 个推定“气孔信号”基因进行比较。讨论了这些实验的结果以及它们与环境信号传导的关系，以及系统信号传导的可能机制。
Light intensity and atmospheric CO2 partial pressure are two environmental signals known to regulate stomatal numbers. It has previously been shown that if a mature Arabidopsis leaf is supplied with either elevated CO2 (750 ppm instead of ambient at 370 ppm) or reduced light levels (50 mu mol m(-2) s(-1) instead of 250 mu mol m(-2) s(-1)), the young, developing leaves that are not receiving the treatment grow with a stomatal density as if they were exposed to the treatment. But the signal(s) that it is believed is generated in the mature leaves and transmitted to developing leaves are largely unknown. Photosynthetic rates of treated, mature Arabidopsis leaves increased in elevated CO2 and decreased when shaded, as would be expected. Similarly, the levels of sugars (glucose, fructose, and sucrose) in the treated mature leaves increased in elevated CO2 and decreased with shade treatment. The levels of sugar in developing leaves were also measured and it was found that they mirrored this result even though they were not receiving the shade or elevated CO2 treatment. To investigate the effect of these treatments on global gene expression patterns, transcriptomics analysis was carried out using Affymetrix, 22K, and ATH1 arrays. Total RNA was extracted from the developing leaves after the mature leaves had received either the ambient control treatment, the elevated CO2 treatment, or the shade treatment, or both elevated CO2 and shade treatments for 2, 4, 12, 24, 48, or 96 h. The experiment was replicated four times. Two other experiments were also conducted, one to compare and contrast gene expression in response to plants grown at elevated CO2 and the other to look at the effect of these treatments on the mature leaf. The data were analysed and 915 genes from the untreated, signalled leaves were identified as having expression levels affected by the shade treatment. These genes were then compared with those whose transcript abundance was affected by the shade treatment in the mature treated leaves (1181 genes) and with 220 putative 'stomatal signalling' genes previously identified from studies of the yoda mutant. The results of these experiments and how they relate to environmental signalling are discussed, as well as possible mechanisms for systemic signalling.