Transcriptomics of the plant growth regulator Heatin. Transcriptomics of the plant growth regulator Heatin

Temperature passively affects many biological processes. It is therefore challenging to study dedicated temperature signalling pathways orchestrating plant thermomorphogenesis; a suite of elongation growth-based adaptations that enhance leaf cooling capacity. Following a chemical genetics approach, we screened a chemical library for compounds that restored abolished hypocotyl elongation in the pif4-2 deficient mutant background in the model plant Arabidopsis thaliana. The small aromatic compound ‘Heatin' (N'-[(2-hydroxy-1-naphthyl)methylene]-2-(1-naphthylamino)propanohydrazide), with 1-aminomethyl-2-naphthol, as minimal active moiety, was isolated as potent enhancer of elongation growth. Here we assessed the transcriptomic changes induced by the compound, by supplementing the MS-agar growth medium with Heatin compared to DMSO solvent, in whole seedlings of the Col-0 wild type background in control (22oC) and high ambient temperature conditions (27oC). Overall design: Pooled seedlings, grown on sterile MS-agar plates, harvested at dawn of day 3 after initiation of germination (2 day old) and of day 8 (7 day old), in 3 replicates per mutant of 3 pooled independent batches (>50 seedlings per batch), genotype and temperature environment in short day conditions.

温度可被动影响诸多生物学过程，因此研究调控植物热形态建成（thermomorphogenesis）的特异性温度信号通路颇具挑战——植物热形态建成是一系列基于伸长生长的适应性反应，可提升叶片的降温能力。本研究采用化学遗传学方法，以模式植物拟南芥（Arabidopsis thaliana）的pif4-2缺失突变体为遗传背景，从化学文库中筛选能够恢复其丧失的下胚轴伸长能力的化合物。最终分离得到一种小型芳香族化合物"Heatin"（化学名：N'-[(2-羟基-1-萘基)亚甲基]-2-(1-萘基氨基)丙酰肼），其最小活性基团为1-氨甲基-2-萘酚，可作为强效的伸长生长促进剂。本研究通过在MS-琼脂（MS-agar）培养基中添加Heatin，以添加二甲基亚砜（DMSO）的培养基作为溶剂对照，分别在对照温度（22℃）与高温环境（27℃）下，检测Col-0野生型背景下完整幼苗中该化合物诱导的转录组变化。实验设计：将幼苗在无菌MS-琼脂平板上培养，分别在萌发后第3天（2日龄幼苗）和第8天（7日龄幼苗）的黎明时分取材；每个基因型、温度环境及处理组均设置3次生物学重复，每次重复由3批独立混合的幼苗组成（每批≥50株幼苗），所有实验均在短日照条件下开展。