Pratiwi Putri, Tanaka Genta, Takahashi Tomohiro, Xie Xiaonan, Yoneyama Koichi, Matsuura Hideyuki, Takahashi Kosaku
Division of Fundamental Agriscience Research, Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Japan.
Plant Cell Physiol. 2017 Apr 1;58(4):789-801. doi: 10.1093/pcp/pcx031.
Jasmonic acid (JA) is involved in a variety of physiological responses in seed plants. However, the detection and role of JA in lycophytes, a group of seedless vascular plants, have remained elusive until recently. This study provides the first evidence of 12-oxo-phytodienoic acid (OPDA), JA and jasmonoyl-isoleucine (JA-Ile) in the model lycophyte Selaginella moellendorffii. Mechanical wounding stimulated the accumulation of OPDA, JA and JA-Ile. These data were corroborated by the detection of enzymatically active allene oxide synthase (AOS), allene oxide cyclase (AOC), 12-oxo-phytodienoic acid reductase 3 (OPR3) and JA-Ile synthase (JAR1) in S. moellendorffii. SmAOS2 is involved in the first committed step of JA biosynthesis. SmAOC1 is a crucial enzyme for generating the basic structure of jasmonates and is actively involved in the formation of OPDA. SmOPR5, a functionally active OPR3-like enzyme, is also vital for the reduction of (+)-cis-OPDA, the only isomer of the JA precursor. The conjugation of JA to Ile by SmJAR1 demonstrates that S. moellendorffii produces JA-Ile. Thus, the four active enzymes have characteristics similar to those in seed plants. Wounding and JA treatment induced the expression of SmAOC1 and SmOPR5. Furthermore, JA inhibited the growth of shoots in S. moellendorffii, which suggests that JA functions as a signaling molecule in S. moellendorffii. This study proposes that JA evolved as a plant hormone for stress adaptation, beginning with the emergence of vascular plants.
茉莉酸（JA）参与种子植物的多种生理反应。然而，直到最近，JA在石松类植物（一类无种子维管植物）中的检测及作用仍不清楚。本研究首次在模式石松类植物卷柏中发现了12-氧代植物二烯酸（OPDA）、JA和茉莉酰异亮氨酸（JA-Ile）。机械损伤刺激了OPDA、JA和JA-Ile的积累。卷柏中具有酶活性的丙二烯氧化物合酶（AOS）、丙二烯氧化物环化酶（AOC）、12-氧代植物二烯酸还原酶3（OPR3）和JA-Ile合酶（JAR1）的检测证实了这些数据。SmAOS2参与JA生物合成的第一步关键反应。SmAOC1是生成茉莉酸类基本结构的关键酶，积极参与OPDA的形成。SmOPR5是一种具有功能活性的类OPR3酶，对JA前体的唯一异构体（+）-顺式OPDA的还原也至关重要。SmJAR1将JA与异亮氨酸偶联，表明卷柏能产生JA-Ile。因此，这四种活性酶具有与种子植物中类似的特征。创伤和JA处理诱导了SmAOC1和SmOPR5的表达。此外，JA抑制了卷柏茎的生长，这表明JA在卷柏中作为一种信号分子发挥作用。本研究提出，从维管植物出现开始，JA就进化成为一种用于应激适应的植物激素。
