Temporal Dynamics of Growth and Photosynthesis Suppression in Response to Jasmonate Signaling
Temporal Dynamics of Growth and Photosynthesis Suppression in Response to Jasmonate Signaling
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DOI：
10.1104/pp.114.239004
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发表时间：
2014-07-01
期刊：
影响因子：
7.4
通讯作者：
Howe, Gregg A.
中科院分区：
文献类型：
--
作者：
Attaran, Elham;Major, Ian T.;Howe, Gregg A.
生物胁迫限制了自然和农业生态系统中的植物生产力。光合作用基因的抑制是植物对生物攻击的保守反应，但这种转录重编程如何与光合作用的变化以及从生长到防御代谢的转变联系在一起还知之甚少。在这里，我们使用了非侵入性的叶绿素荧光成像技术和RNA测序相结合，以确定防御激素茉莉酸（JA）对拟南芥（拟南芥）莲座叶的生长，光合效率和基因表达的影响。通过用冠菌素（COR）（JA受体的高亲和力激动剂）治疗实现了高时间分辨率。我们发现，COR处理后，叶片生长迅速被捕，这种效果是密切相关的基因的表达变化，参与生长，光合作用，防御。快速COR诱导的防御基因的表达发生伴随着光合基因的抑制，但不与光系统II的量子效率降低。这些发现支持了这样的观点，即在胁迫诱导的JA信号将代谢从生长重定向到防御的过程中，光合能力得以维持。然而，在多尺度时间序列中捕获的叶绿素荧光图像显示，在处理后的第二天黎明，光系统II的量子效率出现短暂的COR诱导的降低。生理学研究表明，这种反应的结果延迟气孔开放在昼夜转换。这些集体的结果建立了一个高分辨率的时间视图，如何一个主要的压力响应途径调节植物生长和光合作用，并突出了实用的叶绿素荧光成像揭示短暂的压力引起的扰动光合性能。
Biotic stress constrains plant productivity in natural and agricultural ecosystems. Repression of photosynthetic genes is a conserved plant response to biotic attack, but how this transcriptional reprogramming is linked to changes in photosynthesis and the transition from growth-to defense-oriented metabolism is poorly understood. Here, we used a combination of noninvasive chlorophyll fluorescence imaging technology and RNA sequencing to determine the effect of the defense hormone jasmonate (JA) on the growth, photosynthetic efficiency, and gene expression of Arabidopsis (Arabidopsis thaliana) rosette leaves. High temporal resolution was achieved through treatment with coronatine (COR), a high-affinity agonist of the JA receptor. We show that leaf growth is rapidly arrested after COR treatment and that this effect is tightly correlated with changes in the expression of genes involved in growth, photosynthesis, and defense. Rapid COR-induced expression of defense genes occurred concomitantly with the repression of photosynthetic genes but was not associated with a reduced quantum efficiency of photosystem II. These findings support the view that photosynthetic capacity is maintained during the period in which stress-induced JA signaling redirects metabolism from growth to defense. Chlorophyll fluorescence images captured in a multiscale time series, however, revealed a transient COR-induced decrease in quantum efficiency of photosystem II at dawn of the day after treatment. Physiological studies suggest that this response results from delayed stomatal opening at the night-day transition. These collective results establish a high-resolution temporal view of how a major stress response pathway modulates plant growth and photosynthesis and highlight the utility of chlorophyll fluorescence imaging for revealing transient stress-induced perturbations in photosynthetic performance.