Changes of global gene expression and secondary metabolite accumulation during light-dependent Aspergillus nidulans development
Changes of global gene expression and secondary metabolite accumulation during light-dependent Aspergillus nidulans development
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DOI：
10.1016/j.fgb.2016.01.004
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发表时间：
2016-02-01
影响因子：
3
通讯作者：
Braus, Gerhard H.
中科院分区：
文献类型：
--
作者：
Bayram, Ozgur;Feussner, Kirstin;Braus, Gerhard H.
真菌的发育和次生代谢物的产生是由三聚体天鹅绒复合体等调节复合体协调的。光加速了丝状真菌中性曲霉的无性发育，但减少了性发育。基因表达和次生代谢物积累在环境刺激下的变化一直是许多研究的重点，但缺乏对整个发育过程的全面比较。我们比较了真菌在黑暗或光照下发育过程中转录物和代谢物的快照。将沉水营养菌丝与表面发育进行比较，发现有2.014个基因存在差异表达，占基因组总数的19%。分化在光照条件下优先为无性分化，在黑暗条件下则优先为有性分化，这与无性发育延迟有关。光在转移到表面后的第一个24-48小时内显著诱导基因表达。许多光诱导基因也在黑暗中延迟两天后表达，这可能是为增强性发育做准备所必需的。黑暗导致大量的转录重编程，导致在早期性发育期间脂质来源的真菌信息素合成（psi因子）的高峰，以及细胞壁降解基因的表达，可能是为了动员性别分化的能量。次生代谢物如抗肿瘤terrequinone A或emericellamide在光照条件下开始积累，而霉菌毒素sterigmatocystin或asperthecin和大黄素在性发育的黑暗条件下出现。暗处理72 ~ 96 h后，氨基酸合成和氨基酸池迅速下降。随后的凋亡细胞死亡途径在黑暗中发生的时间明显晚于光明。这表明真菌在分化和次生代谢物生产方面对光照条件的适应需要其基因组潜力的五分之一的重编程。(C) 2016 Elsevier Inc.版权所有。
Fungal development and secondary metabolite production are coordinated by regulatory complexes as the trimeric velvet complex. Light accelerates asexual but decreases sexual development of the filamentous fungus Aspergillus nidulans. Changes in gene expression and secondary metabolite accumulation in response to environmental stimuli have been the focus of many studies, but a comprehensive comparison during entire development is lacking. We compared snapshots of transcript and metabolite profiles during fungal development in dark or light. Overall 2.014 genes corresponding to 19% of the genome were differentially expressed when submerged vegetative hyphae were compared to surface development. Differentiation was preferentially asexual in light or preferentially sexual connected to delayed asexual development in dark. Light induces significantly gene expression within the first 24-48 h after the transfer to surfaces. Many light induced genes are also expressed in dark after a delay of up to two days, which might be required for preparation of enhanced sexual development. Darkness results in a massive transcriptional reprogramming causing a peak of lipid-derived fungal pheromone synthesis (psi factors) during early sexual development and the expression of genes for cell-wall degradation presumably to mobilize the energy for sexual differentiation. Accumulation of secondary metabolites like antitumoral terrequinone A or like emericellamide start under light conditions, whereas the mycotoxin sterigmatocystin or asperthecin and emodin appear under dark conditions during sexual development. Amino acid synthesis and pool rapidly drop after 72-96 h in dark. Subsequent initiation of apoptotic cell-death pathways in darkness happens significantly later than in light. This illustrates that fungal adaptation in differentiation and secondary metabolite production to light conditions requires the reprogramming of one fifth of the potential of its genome. (C) 2016 Elsevier Inc. All rights reserved.