Zhang Haiyan, Zhang Hui, Lin Jinxing
Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin, 300387, China.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
New Phytol. 2020 Jun;226(6):1573-1582. doi: 10.1111/nph.16495. Epub 2020 Mar 27.
Systemin, a peptide plant hormone of 18 amino acids, coordinates local and systemic immune responses. The activation of the canonical systemin-mediated systemic signaling pathway involves systemin release from its precursor prosystemin, systemin binding to its membrane receptor SYSTEMIN RECEPTOR1 (SYR1), and the transport of long-distance signaling molecules, including jasmonic acid, the prosystemin mRNA, volatile organic compounds and possibly systemin itself. Here, we review emerging evidence that the disordered structure and unconventional processing and secretion of systemin contribute to the regulation of systemin-mediated signaling during plant defense. We highlight recent advances in systemin research, which elucidated how cells integrate multiple long-distance signals into the systemic defense response. In addition, we discuss the perception of systemin by SYR1 and its mediation of downstream defense responses.
系统素是一种由18个氨基酸组成的肽类植物激素，可协调局部和全身免疫反应。经典的系统素介导的全身信号通路的激活涉及系统素从前体前系统素的释放、系统素与其膜受体系统素受体1（SYR1）的结合，以及包括茉莉酸、前系统素mRNA、挥发性有机化合物以及可能还有系统素本身在内的长距离信号分子的运输。在这里，我们综述了新出现的证据，即系统素的无序结构以及非常规加工和分泌有助于植物防御过程中系统素介导的信号传导的调节。我们强调了系统素研究的最新进展，这些进展阐明了细胞如何将多个长距离信号整合到全身防御反应中。此外，我们还讨论了SYR1对系统素的识别及其对下游防御反应的介导作用。
