Simeoni Fabio, Skirycz Aleksandra, Simoni Laura, Castorina Giulia, de Souza Leonardo Perez, Fernie Alisdair R, Alseekh Saleh, Giavalisco Patrick, Conti Lucio, Tonelli Chiara, Galbiati Massimo
Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy.
Boyce Thompson Institute, Ithaca, NY, USA.
Sci Rep. 2022 Jan 11;12(1):533. doi: 10.1038/s41598-021-04433-y.
Stomata are epidermal pores formed by pairs of specialized guard cells, which regulate gas exchanges between the plant and the atmosphere. Modulation of transcription has emerged as an important level of regulation of stomatal activity. The AtMYB60 transcription factor was previously identified as a positive regulator of stomatal opening, although the details of its function remain unknown. Here, we propose a role for AtMYB60 as a negative modulator of oxylipins synthesis in stomata. The atmyb60-1 mutant shows reduced stomatal opening and accumulates increased levels of 12-oxo-phytodienoic acid (12-OPDA), jasmonic acid (JA) and jasmonoyl-L-isoleucine (JA-Ile) in guard cells. We provide evidence that 12-OPDA triggers stomatal closure independently of JA and cooperatively with abscisic acid (ABA) in atmyb60-1. Our study highlights the relevance of oxylipins metabolism in stomatal regulation and indicates AtMYB60 as transcriptional integrator of ABA and oxylipins responses in guard cells.
气孔是由成对的特化保卫细胞形成的表皮孔隙，其调节植物与大气之间的气体交换。转录调控已成为气孔活动调控的一个重要层面。AtMYB60转录因子先前被鉴定为气孔开放的正调控因子，但其功能细节仍不清楚。在这里，我们提出AtMYB60在气孔中作为氧脂合成的负调控因子的作用。atmyb60 - 1突变体的气孔开放减少，保卫细胞中12-氧代植物二烯酸（12-OPDA）、茉莉酸（JA）和茉莉酰-L-异亮氨酸（JA-Ile）的积累水平增加。我们提供的证据表明，在atmyb60 - 1中，12-OPDA独立于JA并与脱落酸（ABA）协同触发气孔关闭。我们的研究突出了氧脂代谢在气孔调控中的相关性，并表明AtMYB60是保卫细胞中ABA和氧脂反应的转录整合因子。
