Darwish Essam, Ghosh Ritesh, Ontiveros-Cisneros Abraham, Tran Huy Cuong, Petersson Marcus, De Milde Liesbeth, Broda Martyna, Goossens Alain, Van Moerkercke Alex, Khan Kasim, Van Aken Olivier
Department of Biology, Lund University, Lund, Sweden.
Plant Physiology Section, Agricultural Botany Department, Faculty of Agriculture, Cairo University, Egypt.
Sci Adv. 2022 May 20;8(20):eabm2091. doi: 10.1126/sciadv.abm2091.
Plants respond to mechanical stimuli to direct their growth and counteract environmental threats. Mechanical stimulation triggers rapid gene expression changes and affects plant appearance (thigmomorphogenesis) and flowering. Previous studies reported the importance of jasmonic acid (JA) in touch signaling. Here, we used reverse genetics to further characterize the molecular mechanisms underlying touch signaling. We show that Piezo mechanosensitive ion channels have no major role in touch-induced gene expression and thigmomorphogenesis. In contrast, the receptor-like kinase Feronia acts as a strong negative regulator of the JA-dependent branch of touch signaling. Last, we show that calmodulin-binding transcriptional activators CAMTA1/2/3 are key regulators of JA-independent touch signaling. CAMTA1/2/3 cooperate to directly bind the promoters and activate gene expression of JA-independent touch marker genes like and . In agreement, mutants show a near complete loss of thigmomorphogenesis and touch-induced delay of flowering. In conclusion, we have now identified key regulators of two independent touch-signaling pathways.
植物对机械刺激做出反应，以引导其生长并抵御环境威胁。机械刺激会触发快速的基因表达变化，并影响植物外观（触形态建成）和开花。先前的研究报道了茉莉酸（JA）在触觉信号传导中的重要性。在这里，我们使用反向遗传学进一步表征触觉信号传导的分子机制。我们表明，压电机械敏感离子通道在触摸诱导的基因表达和触形态建成中没有主要作用。相比之下，类受体激酶Feronia作为触觉信号传导中依赖JA分支的强负调节因子。最后，我们表明钙调蛋白结合转录激活因子CAMTA1/2/3是不依赖JA的触觉信号传导的关键调节因子。CAMTA1/2/3协同直接结合启动子并激活不依赖JA的触摸标记基因（如 和 ）的基因表达。一致的是， 突变体显示出几乎完全丧失触形态建成和触摸诱导的开花延迟。总之，我们现在已经确定了两条独立触觉信号通路的关键调节因子。
