BrphyB is critical for rapid recovery to darkness in mature Brassica rapa leaves
BrphyB is critical for rapid recovery to darkness in mature Brassica rapa leaves
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DOI：
10.1101/2020.05.22.111245
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发表时间：
2020-05
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影响因子：
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通讯作者：
Andrej A. Arsovski;Joseph E. Zemke;Morgan O. Hamm;L. Houston;A. Romanowski;K. Halliday;N. Nesi;J. Nemhauser
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文献类型：
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作者：
Andrej A. Arsovski;Joseph E. Zemke;Morgan O. Hamm;L. Houston;A. Romanowski;K. Halliday;N. Nesi;J. Nemhauser
作物生物量和产量与光信号网络如何将环境信息转化为资源分配（包括光合产物）密切相关。一旦被激活，光敏色素（phy）类光感受器发出信号并重新部署碳资源，以改变生长，植物结构和繁殖时间。芜菁已被用作作物模型来测试光敏色素-碳网络的保护。B。芜菁phyB突变体在幼苗中具有显著降低或不存在CO2刺激的生长响应，并且成年植物具有降低的叶绿素水平、光合速率、气孔指数和种子产量。在这里，我们研究了成年野生型和BrphyB叶变暗和恢复光的转录组反应。三天的黑暗足以引起野生型叶片的反应，这表明从碳固定和养分获取到细胞资源的主动再分配的转变。在恢复光照后，野生型叶似乎在转录上恢复到黑暗前的状态，恢复对营养获取的关注。总的来说，BrphyB突变体植物具有类似的响应，其中参与光合作用和光响应的基因存在关键差异，这偏离了野生型转录动力学。靶向叶绿体的基因尤其受到影响。成年BrphyB突变体植物有更少，更大的叶绿体，进一步连接光敏色素，叶绿体发育，光合不足和最佳资源分配。
Crop biomass and yield are tightly linked to how the light signaling network translates information about the environment into allocation of resources, including photosynthates. Once activated, the phytochrome (phy) class of photoreceptors signal and re-deploy carbon resources to alter growth, plant architecture, and reproductive timing. Brassica rapa has been used as a crop model to test for conservation of the phytochrome–carbon network. B. rapa phyB mutants have significantly decreased or absent CO2-stimulated growth responses in seedlings, and adult plants have reduced chlorophyll levels, photosynthetic rate, stomatal index, and seed yield. Here, we examine the transcriptomic response of adult wild-type and BrphyB leaves to darkening and recovery in light. Three days of darkness was sufficient to elicit a response in wild type leaves suggesting a shift from carbon fixation and nutrient acquisition to active redistribution of cellular resources. Upon a return to light, wild-type leaves appeared to transcriptionally return to a pre-darkness state restoring a focus on nutrient acquisition. Overall, BrphyB mutant plants have a similar response with key differences in genes involved in photosynthesis and light response which deviate from the wild type transcriptional dynamics. Genes targeted to the chloroplast are especially affected. Adult BrphyB mutant plants had fewer, larger chloroplasts, further linking phytochromes, chloroplast development, photosynthetic deficiencies and optimal resource allocation.