Transcriptional and Proteomic Choreography Under Phosphorus Deficiency and Re-supply in the N2 Fixing Cyanobacterium Trichodesmium erythraeum
Transcriptional and Proteomic Choreography Under Phosphorus Deficiency and Re-supply in the N2 Fixing Cyanobacterium Trichodesmium erythraeum
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DOI：
10.3389/fmicb.2019.00330
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发表时间：
2019-03-05
影响因子：
5.2
通讯作者：
Dyhrman, Sonya T.
中科院分区：
文献类型：
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作者：
Frischkorn, Kyle R.;Haley, Sheean T.;Dyhrman, Sonya T.
固氮蓝细菌束毛藻是贫营养海洋生态系统中一种极其重要的生物，为氮缺乏的热带和亚热带地区提供"新"氮（N）。低浓度的磷（P）在这些地区可以限制束毛藻的分布和N-2固定率。混合群落中单一物种的生理特性可能具有挑战性，并且组学方法是以分类特异性方式跟踪营养生理的越来越重要的工具。因此，研究生理学的基因和蛋白质标记物的动态（例如，营养胁迫）对于原位应用和解释此类组学数据至关重要。在这里，我们利用联合转录组学，蛋白质组学和酶活性测定跟踪的生理反应Trichodesmium pyrraeum IMS 101磷缺乏和随后的P再供应超过72小时的采样。磷缺乏导致差异的基因表达，蛋白质丰度，和酶活性，突出了同步转变P生理与增加的成绩单和相应的蛋白质水解有机磷，采取磷酸盐具有更高的亲和力，和调节细胞内的磷需求。在磷缺乏缓解后，这些生物标志物的基因表达在磷修正后4小时内降低到完全水平。这些基因生物标志物中的一些与推定的pho盒相邻，并且它们的表达模式类似于一个p53受体反应调节剂。磷缺乏生物标志物的蛋白产物缓慢下降，72小时后84%的原始磷缺乏蛋白组仍显著差异表达。碱性磷酸酶活性与蛋白质跟踪这种酶。由于转录物的周转时间快，它们似乎是P应激表型的良好生物标志物，而周转时间较慢的蛋白质可能更好地反映细胞活性。这些结果强调了验证和配对转录组和蛋白质组数据的重要性，这些数据可应用于关键物种的原位生理研究。
The N(2 )fixing cyanobacterium Trichodesmium is a critically important organism in oligotrophic marine ecosystems, supplying "new" nitrogen (N) to the otherwise N-poor tropical and subtropical regions where it occurs. Low concentrations of phosphorus (P) in these regions can constrain Trichodesmium distribution and N-2 fixation rates. Physiological characterization of a single species in a mixed community can be challenging, and 'omic approaches are increasingly important tools for tracking nutritional physiology in a taxon-specific manner. As such, studies examining the dynamics of gene and protein markers of physiology (e.g., nutrient stress) are critical for the application and interpretation of such 'omic data in situ. Here we leveraged combined transcriptomics, proteomics, and enzyme activity assays to track the physiological response of Trichodesmium erythraeum IMS101 to P deficiency and subsequent P re-supply over 72 h of sampling. P deficiency resulted in differential gene expression, protein abundance, and enzyme activity that highlighted a synchronous shift in P physiology with increases in the transcripts and corresponding proteins for hydrolyzing organic phosphorus, taking up phosphate with higher affinity, and modulating intracellular P demand. After P deficiency was alleviated, gene expression of these biomarkers was reduced to replete levels within 4 h of P amendment. A number of these gene biomarkers were adjacent to putative pho boxes and their expression patterns were similar to a sphR response regulator. Protein products of the P deficiency biomarkers were slow to decline, with 84% of the original P deficient protein set still significantly differentially expressed after 72 h. Alkaline phosphatase activity tracked with proteins for this enzyme. With the rapid turnover time of transcripts, they appear to be good biomarkers of a P stress phenotype, whereas proteins, with a slower turnover time, may better reflect cellular activities. These results highlight the importance of validating and pairing transcriptome and proteome data that can be applied to physiological studies of key species in situ.