Making Epidermal Bladder Cells Bigger: Developmental-and Salinity-Induced Endopolyploidy in a Model Halophyte
Making Epidermal Bladder Cells Bigger: Developmental-and Salinity-Induced Endopolyploidy in a Model Halophyte
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DOI：
10.1104/pp.18.00033
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发表时间：
2018-06-01
期刊：
影响因子：
7.4
通讯作者：
Dassanayake, Maheshi
中科院分区：
文献类型：
--
作者：
Barkla, Bronwyn J.;Rhodes, Timothy;Dassanayake, Maheshi
当DNA复制发生时，没有随后的有丝分裂核分裂，导致组织内细胞特异性倍性水平。在植物中，内多倍体在维持生长发育中起着重要作用，但只有少数研究证实其在非生物胁迫反应中起作用。本研究研究了盐生植物晶体间胚（Mesembryanthemum crystallinum）的倍性水平、细胞核和细胞大小在叶片发育过程中的作用，并追踪了细胞类型特异性倍性。除了发育性内多倍体外，我们还研究了盐度胁迫对倍性水平的影响。我们特别关注了表皮膀胱细胞（EBC），这是一种改良的球囊样毛状细胞，由于它们的大尺寸和在盐积累中的作用。结果表明，各叶型的倍性均随着叶片的扩张而增加，其倍性最高可达512C。盐处理显著提高了EBC的倍性水平，这些细胞的倍性、细胞核和细胞大小随叶和茎表面位置的不同而呈现空间相关差异。转录组分析强调了盐度诱导的EBC中涉及DNA复制、细胞周期、内复制和毛状体发育的基因的变化。盐胁迫下结晶m.s nlamum细胞大小和倍性的增加可能是由于叶片组织和EBC中较高的代谢活性导致细胞快速增大，从而增加了固钠的储存能力，从而促进了其耐盐性。
Endopolyploidy occurs when DNA replication takes place without subsequent mitotic nuclear division, resulting in cell-specific ploidy levels within tissues. In plants, endopolyploidy plays an important role in sustaining growth and development, but only a few studies have demonstrated a role in abiotic stress response. In this study, we investigated the function of ploidy level and nuclear and cell size in leaf expansion throughout development and tracked cell type-specific ploidy in the halophyte Mesembryanthemum crystallinum. In addition to developmental endopolyploidy, we examined the effects of salinity stress on ploidy level. We focused specifically on epidermal bladder cells ( EBC), which are modified balloon-like trichomes, due to their large size and role in salt accumulation. Our results demonstrate that ploidy increases as the leaves expand in a similar manner for each leaf type, and ploidy levels up to 512C were recorded for nuclei in EBC of leaves of adult plants. Salt treatment led to a significant increase in ploidy levels in the EBC, and these cells showed spatially related differences in their ploidy and nuclear and cell size depending on the positions on the leaf and stem surface. Transcriptome analysis highlighted salinity-induced changes in genes involved in DNA replication, cell cycle, endoreduplication, and trichome development in EBC. The increase in cell size and ploidy observed in M. crystallinum under salinity stress may contribute to salt tolerance by increasing the storage capacity for sodium sequestration brought about by higher metabolic activity driving rapid cell enlargement in the leaf tissue and EBC.