Stief Anna, Altmann Simone, Hoffmann Karen, Pant Bikram Datt, Scheible Wolf-Rüdiger, Bäurle Isabel
Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany.
Max-Planck-Institute for Molecular Plant Physiology, 14476 Potsdam, Germany.
Plant Cell. 2014 Apr;26(4):1792-1807. doi: 10.1105/tpc.114.123851. Epub 2014 Apr 25.
Plants are sessile organisms that gauge stressful conditions to ensure survival and reproductive success. While plants in nature often encounter chronic or recurring stressful conditions, the strategies to cope with those are poorly understood. Here, we demonstrate the involvement of ARGONAUTE1 and the microRNA pathway in the adaptation to recurring heat stress (HS memory) at the physiological and molecular level. We show that miR156 isoforms are highly induced after HS and are functionally important for HS memory. miR156 promotes sustained expression of HS-responsive genes and is critical only after HS, demonstrating that the effects of modulating miR156 on HS memory do not reflect preexisting developmental alterations. miR156 targets SPL transcription factor genes that are master regulators of developmental transitions. SPL genes are posttranscriptionally downregulated by miR156 after HS, and this is critical for HS memory. Altogether, the miR156-SPL module mediates the response to recurring HS in Arabidopsis thaliana and thus may serve to integrate stress responses with development.
植物是固着生物，它们能够感知压力条件以确保生存和繁殖成功。虽然自然界中的植物经常遇到慢性或反复出现的压力条件，但应对这些条件的策略却知之甚少。在这里，我们在生理和分子水平上证明了AGO1（AGO1蛋白）和微小RNA途径参与了对反复热胁迫的适应（热胁迫记忆）。我们表明，miR156（微小RNA156）亚型在热胁迫后被高度诱导，并且对热胁迫记忆具有重要功能。miR156促进热胁迫响应基因的持续表达，并且仅在热胁迫后才至关重要，这表明调节miR156对热胁迫记忆的影响并不反映先前存在的发育改变。miR156靶向SPL转录因子基因，这些基因是发育转变的主要调节因子。热胁迫后，SPL基因在转录后被miR156下调，这对热胁迫记忆至关重要。总之，miR156-SPL模块介导了拟南芥对反复热胁迫的响应，因此可能有助于将应激反应与发育整合起来。
