The role of carbon starvation in the induction of enzymes that degrade plant-derived carbohydrates in Aspergillus niger.
The role of carbon starvation in the induction of enzymes that degrade plant-derived carbohydrates in Aspergillus niger.
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DOI：
10.1016/j.fgb.2014.04.006
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发表时间：
2014-11
期刊：
影响因子：
--
通讯作者：
Archer DB
中科院分区：
文献类型：
--
作者：
van Munster JM;Daly P;Delmas S;Pullan ST;Blythe MJ;Malla S;Kokolski M;Noltorp ECM;Wennberg K;Fetherston R;Beniston R;Yu X;Dupree P;Archer DB
黑曲霉对麦秸的转录组反应是顺序的。早期反应由编码半纤维素水解酶的基因组成。对秸秆的后期反应由编码纤维素酶和果胶酶的基因组成。对碳饥饿的早期反应与对麦秆的反应重叠。饥饿培养物中的酶从木质纤维素中释放单糖和低聚糖。真菌是植物多糖糖化和生物燃料生产酶的重要来源。对编码这些酶的基因的调控和诱导表达的理解仍然不完整。为了探索诱导机制，我们分析了工业上重要的真菌黑曲霉对麦秸的反应，重点研究了暴露于底物后不久发生的事件。RNA测序显示，暴露于麦秸6 h后的转录反应与暴露于同一底物24 h时的转录反应有很大不同。例如，在暴露于麦秸24小时后诱导的编码碳水化合物活性酶的基因中，只有不到一半在暴露于麦秸6小时后也被诱导。重要的是，超过三分之一的暴露于麦秸6 h后诱导的基因在碳饥饿6 h时也被诱导，这表明碳饥饿可能是麦秸早期反应的一个重要因素。在早期碳饥饿过程中，对植物源性碳水化合物有活性的CAZymes编码基因的大量表达上调表明，这些酶可能在饥饿过程中参与侦察作用，从复杂的植物多糖中释放诱导糖。我们利用蛋白质组学证明，碳匮乏的培养物确实释放出对植物多糖具有预期活性的CAZymes。酶活性和反应产物的分析表明，这些蛋白质是酶，可以降解各种植物多糖，产生已知的和潜在的新的CAZymes诱导剂。
The transriptomic response of Aspergillus niger to wheat straw is sequential. The early response consists of genes encoding hemicellulolytic enzymes. The later response to straw consists of genes encoding cellulases and pectinases. The early response to carbon starvation overlaps with that to wheat straw. CAZymes in starved cultures release mono- and oligosaccharides from lignocellulose. Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that the transcriptional response after 6 h of exposure to wheat straw was very different from the response at 24 h of exposure to the same substrate. For example, less than half of the genes encoding carbohydrate active enzymes that were induced after 24 h of exposure to wheat straw, were also induced after 6 h exposure. Importantly, over a third of the genes induced after 6 h of exposure to wheat straw were also induced during 6 h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides. We show, using proteomics, that carbon-starved cultures indeed release CAZymes with predicted activity on plant polysaccharides. Analysis of the enzymatic activity and the reaction products, indicates that these proteins are enzymes that can degrade various plant polysaccharides to generate both known, as well as potentially new, inducers of CAZymes.
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影响因子：
4.4
作者：
Couturier M;Navarro D;Olivé C;Chevret D;Haon M;Favel A;Lesage-Meessen L;Henrissat B;Coutinho PM;Berrin JG
通讯作者：
Berrin JG
影响因子：
3.6
作者：
Benz JP;Chau BH;Zheng D;Bauer S;Glass NL;Somerville CR
通讯作者：
Somerville CR
影响因子：
6.3
作者：
de Souza WR;de Gouvea PF;Savoldi M;Malavazi I;de Souza Bernardes LA;Goldman MHS;de Vries RP;de Castro Oliveira JV;Goldman GH
通讯作者：
Goldman GH
影响因子：
2.5
作者：
BOS, CJ;DEBETS, AJM;SLAKHORST, SM
通讯作者：
SLAKHORST, SM
影响因子：
4.5
作者：
Delmas S;Pullan ST;Gaddipati S;Kokolski M;Malla S;Blythe MJ;Ibbett R;Campbell M;Liddell S;Aboobaker A;Tucker GA;Archer DB
通讯作者：
Archer DB