Cañibano Esther, Rodríguez-Sánchez Natalia, Gómez-Soto Daniela, El Kendi Fatima Zahra, Lozano-Juste Jorge, Kinoshita Toshinori, Oliveros Juan Carlos, Bourbousse Clara, Fonseca Sandra
Centro Nacional de Biotecnología (CNB)-CSIC, Madrid 28049, Spain.
Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València, CSIC, Valencia 46022, Spain.
Sci Adv. 2025 Jun 27;11(26):eadv0895. doi: 10.1126/sciadv.adv0895.
Driven by cell elongation, hypocotyl growth is tightly controlled by light and responds to the stress signaling hormone abscisic acid (ABA). However, the molecular connections between ABA and light to control cell elongation are poorly understood. Here, we show that, in Arabidopsis, ABA inhibits hypocotyl elongation in the light but not in the dark. In the dark, hypocotyl sensitivity to ABA is restored in and mutants, suggesting that an active light signaling pathway is necessary for hypocotyl responsiveness to ABA. Through an RNA sequencing subtractive approach, we identified ABA differentially expressed genes that correlate with ABA inhibition of hypocotyl elongation, including several genes. The abrogation of PP2C.D2-SAUR interaction in the / line restored ABA sensitivity in the dark, suggesting that SAUR proteins are key to maintain hypocotyls insensitive to ABA. This hypocotyl-specific mechanism enables growth toward the light, overriding ABA inhibition of cell elongation, ensuring subsequent seedling establishment and survival.
在细胞伸长的驱动下，下胚轴的生长受到光的严格控制，并对胁迫信号激素脱落酸（ABA）产生响应。然而，ABA与光之间控制细胞伸长的分子联系却鲜为人知。在这里，我们表明，在拟南芥中，ABA在光照下抑制下胚轴伸长，但在黑暗中则不然。在黑暗中， 和 突变体中下胚轴对ABA的敏感性恢复，这表明活跃的光信号通路对于下胚轴对ABA的响应是必需的。通过RNA测序消减方法，我们鉴定出了与ABA抑制下胚轴伸长相关的ABA差异表达基因，包括几个 基因。 / 品系中PP2C.D2-SAUR相互作用的消除恢复了黑暗中的ABA敏感性，这表明SAUR蛋白是维持下胚轴对ABA不敏感的关键。这种下胚轴特异性机制使植物能够向光生长，克服ABA对细胞伸长的抑制，确保幼苗随后的建立和存活。
