A NAP-Family Histone Chaperone Functions in Abiotic Stress Response and Adaptation
A NAP-Family Histone Chaperone Functions in Abiotic Stress Response and Adaptation
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DOI：
10.1104/pp.16.00408
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发表时间：
2016-08-01
期刊：
影响因子：
7.4
通讯作者：
Singla-Pareek, Sneh Lata
中科院分区：
文献类型：
--
作者：
Tripathi, Amit K.;Pareek, Ashwani;Singla-Pareek, Sneh Lata
基因表达调控是植物非生物胁迫反应的重要分子机制之一。组蛋白伴侣蛋白通过改变DNA的可及性，影响基因组基因座的转录能力。然而，与其他影响染色质动态的因素不同，植物组蛋白伴侣蛋白在非生物胁迫反应和适应中的作用仍然难以捉摸。在这里，我们研究了NAP超家族中一个逆境反应可能的水稻(Oryza Sativa)组蛋白伴侣蛋白OsNAPL6的生理功能。我们证明了OsNAPL6是一种核定位的H3/H4组蛋白伴侣蛋白，能够组装成核小体样结构。利用过表达和敲除方法，我们发现OsNAPL6的表达水平与对多种非生物胁迫的适应呈正相关。比较转录组图谱和启动子招募研究的结果表明，OsNAPL6在胁迫反应中通过调节参与不同功能的各种基因的表达而发挥作用。例如，我们发现OsNAPL6被招募到OsRad51启动子，激活其表达，并导致更有效的DNA修复和在盐和遗传毒性应激条件下消除细胞程序性死亡。这些结果表明，组蛋白伴侣基因OsNAPL6可能通过调节与胁迫相关的多个基因组位点的核小体动态而在非生物胁迫生理中发挥调节作用。综上所述，我们的发现建立了迄今为止未知的在植物中组蛋白伴侣蛋白和非生物胁迫反应之间的联系。
Modulation of gene expression is one of the most significant molecular mechanisms of abiotic stress response in plants. Via altering DNA accessibility, histone chaperones affect the transcriptional competence of genomic loci. However, in contrast to other factors affecting chromatin dynamics, the role of plant histone chaperones in abiotic stress response and adaptation remains elusive. Here, we studied the physiological function of a stress-responsive putative rice (Oryza sativa) histone chaperone of the NAP superfamily: OsNAPL6. We show that OsNAPL6 is a nuclear-localized H3/H4 histone chaperone capable of assembling a nucleosome-like structure. Utilizing overexpression and knockdown approaches, we found a positive correlation between OsNAPL6 expression levels and adaptation to multiple abiotic stresses. Results of comparative transcriptome profiling and promoter-recruitment studies indicate that OsNAPL6 functions during stress response via modulation of expression of various genes involved in diverse functions. For instance, we show that OsNAPL6 is recruited to OsRad51 promoter, activating its expression and leading to more efficient DNA repair and abrogation of programmed cell death under salinity and genotoxic stress conditions. These results suggest that the histone chaperone OsNAPL6 may serve a regulatory role in abiotic stress physiology possibly via modulating nucleosome dynamics at various stress-associated genomic loci. Taken together, our findings establish a hitherto unknown link between histone chaperones and abiotic stress response in plants.