Gene expression signatures in Arabidopsis thaliana roots under sufficient nitrogen or mild nitrogen deficiency. Gene expression signatures in Arabidopsis thaliana roots under sufficient nitrogen or mild nitrogen deficiency

To optimize access to nitrogen under limiting conditions, root systems must continuously sense and respond to local or temporal fluctuations in nitrogen availability. In Arabidopsis thaliana and several other species, external N levels that induce only mild deficiency stimulate the emergence of lateral roots and especially the elongation of primary and lateral roots. However, the identity of the genes involved in this coordination remains still largely elusive. In order to identify novel genes and mechanisms underlying nitrogen-dependent root morphological changes, we investigated time-dependent changes in the root transcriptome of Arabidopsis thaliana plants grown under sufficient nitrogen or under conditions that induced mild nitrogen deficiency. Overall design: Gene expression in whole roots of Arabidopsis thaliana was measured after transferring seven-day-old seedlings for 0, 1, 2 and 4 days to 11.4 mM nitrogen (N-sufficient; control) or 0.55 mM nitrogen (mild N deficiency). Three biological replicates were used.

为在氮素限制条件下优化氮素获取能力，植物根系必须持续感知并响应氮素有效性的局部或时序波动。在拟南芥（Arabidopsis thaliana）及其他多个物种中，仅能诱导轻度氮素缺乏的外源氮浓度，可刺激侧根发生，尤其能促进主根与侧根的伸长。然而，介导这一协调作用的相关基因，其功能与身份仍在很大程度上尚不明确。为鉴定氮素依赖型根系形态变化背后的新基因与调控机制，我们对生长于氮素充足条件，或轻度氮素缺乏诱导条件下的拟南芥植株根系转录组的时序动态变化进行了分析。总体实验设计：将7日龄拟南芥幼苗分别移植至11.4 mM氮素（氮素充足；对照组）或0.55 mM氮素（轻度氮素缺乏）的培养基中，分别培养0、1、2、4天后，检测其全根的基因表达水平。本实验设置3次生物学重复。