Engineering secondary cell wall deposition in plants.
Engineering secondary cell wall deposition in plants.
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DOI：
10.1111/pbi.12016
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发表时间：
2013-04
影响因子：
13.8
通讯作者：
Loqué D
中科院分区：
文献类型：
--
作者：
Yang F;Mitra P;Zhang L;Prak L;Verhertbruggen Y;Kim JS;Sun L;Zheng K;Tang K;Auer M;Scheller HV;Loqué D
几千年来，木质纤维素生物质一直被用作动物饲料，现在被认为是生产生物燃料的重要糖源。它主要由嵌入木质素的多糖聚合物构建的次级细胞壁组成，以加强细胞壁结构并保持其完整性。木质素是负责生物质抵抗酶水解的主要物质。在植物发育过程中，木质素的深度减少会导致生长缺陷，并且通常与血管完整性的丧失有关，从而对植物中的水和营养物质运输产生不利影响。本文介绍了一种减少木质素含量同时防止血管塌陷的新方法，并介绍了一种促进天然组织中转录因子表达的新策略。我们在拟南芥中使用合成生物学工具通过改变启动子编码序列关联来重新连接次生细胞网络。结果是木质素的减少和纤维细胞中多糖沉积的增加。木质素关键基因C4H的启动子被转录因子VND6的血管特异性启动子所取代。这重新连接了木质素的生物合成，特别是血管的形成，同时断开了纤维调节网络中C4H的表达。其次，利用IRX8基因的启动子次级细胞壁糖基转移酶（secondary细胞壁糖基转移酶）表达纤维转录因子NST1的新拷贝，由于IRX8启动子是由NST1诱导的，这也创造了一个人工的正反馈回路（APFL）。木质素重新布线和APFL插入策略的结合，增强了茎中的多糖沉积，而不会使茎过度木质素化，从而在酶水解后产生更高的糖产量。
Lignocellulosic biomass was used for thousands of years as animal feed and is now considered a great sugar source for biofuels production. It is composed mostly of secondary cell walls built with polysaccharide polymers that are embedded in lignin to reinforce the cell wall structure and maintain its integrity. Lignin is the primary material responsible for biomass recalcitrance to enzymatic hydrolysis. During plant development, deep reductions of lignin cause growth defects and often correlate with the loss of vessel integrity that adversely affects water and nutrient transport in plants. The work presented here describes a new approach to decrease lignin content while preventing vessel collapse and introduces a new strategy to boost transcription factor expression in native tissues. We used synthetic biology tools in Arabidopsis to rewire the secondary cell network by changing promoter-coding sequence associations. The result was a reduction in lignin and an increase in polysaccharide depositions in fibre cells. The promoter of a key lignin gene, C4H, was replaced by the vessel-specific promoter of transcription factor VND6. This rewired lignin biosynthesis specifically for vessel formation while disconnecting C4H expression from the fibre regulatory network. Secondly, the promoter of the IRX8 gene, secondary cell wall glycosyltransferase, was used to express a new copy of the fibre transcription factor NST1, and as the IRX8 promoter is induced by NST1, this also created an artificial positive feedback loop (APFL). The combination of strategies—lignin rewiring with APFL insertion—enhances polysaccharide deposition in stems without over-lignifying them, resulting in higher sugar yields after enzymatic hydrolysis.
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影响因子：
7.2
作者：
Clough, SJ;Bent, AF
通讯作者：
Bent, AF
影响因子：
4.8
作者：
Blake, Anthony W.;McCartney, Lesley;Knox, J. Paul
通讯作者：
Knox, J. Paul
影响因子：
56.9
作者：
GAN, SS;AMASINO, RM
通讯作者：
AMASINO, RM
DOI：
10.1073/pnas.1117873108
发表时间：
2011-12-20
影响因子：
11.1
作者：
Gallego-Giraldo, Lina;Escamilla-Trevino, Luis;Dixon, Richard A.
通讯作者：
Dixon, Richard A.
影响因子：
5.6
作者：
Handakumbura PP;Hazen SP
通讯作者：
Hazen SP