Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
Department of Molecular Signal Processing, Leibnitz Institute of Plant Biochemistry, 06120 Halle, Germany.
Proc Natl Acad Sci U S A. 2019 Feb 5;116(6):2364-2373. doi: 10.1073/pnas.1817233116. Epub 2019 Jan 23.
In nature, plants must respond to multiple stresses simultaneously, which likely demands cross-talk between stress-response pathways to minimize fitness costs. Here we provide genetic evidence that biotic and abiotic stress responses are differentially prioritized in leaves of different ages to maintain growth and reproduction under combined biotic and abiotic stresses. Abiotic stresses, such as high salinity and drought, blunted immune responses in older rosette leaves through the phytohormone abscisic acid signaling, whereas this antagonistic effect was blocked in younger rosette leaves by , a signaling component of the defense phytohormone salicylic acid. Plants lacking exhibited enhanced abiotic stress tolerance at the cost of decreased fitness under combined biotic and abiotic stresses. Together with this role, is also indispensable for the establishment of salt stress- and leaf age-dependent phyllosphere bacterial communities. Collectively, our work reveals a mechanism that balances trade-offs upon conflicting stresses at the organism level and identifies a genetic intersection among plant immunity, leaf microbiota, and abiotic stress tolerance.
在自然界中，植物必须同时应对多种胁迫，这可能需要胁迫反应途径之间的交流，以最小化适应代价。在这里，我们提供遗传证据表明，生物和非生物胁迫反应在不同年龄的叶片中被不同地优先考虑，以在生物和非生物胁迫的组合下维持生长和繁殖。非生物胁迫，如高盐度和干旱，通过植物激素脱落酸信号削弱了较老的莲座叶的免疫反应，而在较年轻的莲座叶中，这种拮抗作用被防御植物激素水杨酸的信号成分 所阻断。缺乏 的植物在生物和非生物胁迫的组合下表现出增强的非生物胁迫耐受性，但代价是适应能力降低。除了这个作用， 对于盐胁迫和叶片年龄依赖的叶际细菌群落的建立也是必不可少的。总的来说，我们的工作揭示了一种在生物体水平上平衡冲突胁迫之间权衡的机制，并确定了植物免疫、叶际微生物群和非生物胁迫耐受性之间的遗传交叉点。
