Abstract：
H2A.Z-containing nucleosomes have been found to function in various developmental programs in Arabidopsis (e.g., floral transition, warm ambient temperature, and drought stress responses). The SWI2/SNF2-Related 1 Chromatin Remodeling (SWR1) complex is known to control the deposition of H2A.Z, and it has been unraveled that ACTIN-RELATED PROTEIN 6 (ARP6) is one component of this SWR1 complex. Previous studies showed that the arp6 mutant exhibited some distinguished phenotypes such as early flowering, leaf serration, elongated hypocotyl, and reduced seed germination rate in response to osmotic stress. In this study, we aimed to investigate the changes of arp6 mutant when the plants were grown in salt stress condition. The phenotypic observation showed that the arp6 mutant was more sensitive to salt stress than the wild type. Upon salt stress condition, this mutant exhibited attenuated root phenotypes such as shorter primary root length and fewer lateral root numbers. The transcript levels of stress-responsive genes, ABA INSENSITIVE 1 (ABI1) and ABI2, were found to be impaired in the arp6 mutant in comparison with wild-type plants in response to salt stress. In addition, a meta-analysis of published data indicated a number of genes involved in auxin response were induced in arp6 mutant grown in non-stress condition. These imply that the loss of H2A.Z balance (in arp6 mutant) may lead to change stress and auxin responses resulting in alternative root morphogenesis upon both normal and salinity stress conditions.
摘要：
H2A.已发现含Z的核小体在拟南芥的各种发育程序中起作用（例如，花卉过渡，温暖的环境温度，和干旱胁迫响应)。已知SWI2/SNF2相关的1染色质重塑(SWR1)复合物控制H2A的沉积。Z,并且已经揭示了肌动蛋白相关蛋白6（ARP6）是该SWR1复合物的一个组成部分。以前的研究表明，arp6突变体表现出一些明显的表型，如早期开花，叶锯齿，拉长的下胚轴，并降低种子对渗透胁迫的发芽率。在这项研究中,我们的目的是研究植物在盐胁迫条件下生长时arp6突变体的变化。表型观察表明，arp6突变体比野生型对盐胁迫更敏感。在盐胁迫条件下，该突变体表现出减弱的根表型，例如较短的主根长度和较少的侧根数量。应激反应基因的转录水平，与野生型植物相比，在arp6突变体中发现ABA不敏感1（ABI1）和ABI2在盐胁迫下受损。此外,对已发表数据的荟萃分析表明,在非胁迫条件下生长的arp6突变体中诱导了许多与生长素应答有关的基因.这意味着H2A的损失。Z平衡（在arp6突变体中）可能导致胁迫和生长素响应的变化，从而在正常和盐度胁迫条件下产生替代的根形态发生。
