Functional co-expression of a fungal ferulic acid esterase and a β-1,4 endoxylanase in Festuca arundinacea (tall fescue) modifies post-harvest cell wall deconstruction
Functional co-expression of a fungal ferulic acid esterase and a β-1,4 endoxylanase in Festuca arundinacea (tall fescue) modifies post-harvest cell wall deconstruction
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DOI：
10.1007/s00425-015-2288-2
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发表时间：
2015-07-01
期刊：
影响因子：
4.3
通讯作者：
Morris, Phillip
中科院分区：
文献类型：
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作者：
Buanafina, Marcia M. de O.;Dalton, Sue;Morris, Phillip
通过在植物内共同表达阿魏酸酯酶和衰老诱导的β -1,4内木聚糖酶，可以改善高羊茅叶片收获后细胞壁的解构。用里氏木霉诱导衰老的-1,4内切木聚糖酶对表达黑曲霉液泡或外质体靶向阿魏酸酯酶的高羊茅进行了再转化。在重复无性繁殖后，共表达植株的酶活性趋于稳定，衰老叶片的木聚糖酶活性增加，分蘖后阿魏酸酯酶活性降低。与单独表达阿魏酸酯酶或木聚糖酶相比，在体外质体中共表达这两种酶的植物，在阿魏酸单体和二聚体水平最低和细胞壁阿拉伯木聚糖水平最低的情况下，在自消化过程中从细胞壁释放出10倍多的羟基肉桂酸和5倍多的阿拉伯木聚糖。这些植物还显示纤维素酶介导的还原糖释放增加了31%，体外干物质消化率增加了5%，乙酰溴可溶性木质素增加了23%。然而，在外质体中表达FAE会对植物生长产生不利影响，使植物叶片变窄变短，生物量减少71%。
Improved post-harvest cell wall deconstruction of tall fescue leaves has been demonstrated by in-planta co-expression of a constitutively expressed ferulic acid esterase together with a senescence-induced beta-1,4 endoxylanase.Tall fescue plants (Festuca arundinacea) constitutively expressing vacuole- or apoplast-targeted ferulic acid esterase from Aspergillus niger were retransformed with a senescence-induced and apoplast-targeted beta-1,4 endo-xylanase from Trichoderma reesei. Enzyme activities in co-expressing plants stabilized after repeated vegetative propagation, with xylanase activity in senescent leaves increasing and ferulic acid esterase activity decreasing after tillering. Plants co-expressing both enzymes in the apoplast, with the lowest levels of ferulate monomers and dimers and the lowest levels of cell wall arabinoxylans, released ten times more cell wall hydroxycinnamic acids and five times more arabinoxylan from the cell wall on autodigestion compared to expression of ferulic acid esterase or xylanase alone. These plants also showed a 31 % increase in cellulase-mediated release of reducing sugars, a 5 % point increase in in vitro dry matter digestibility and a 23 % increase in acetyl bromide-soluble lignin. However, plant growth was adversely affected by expressing FAE in the apoplast, giving plants with narrower shorted leaves, and a 71 % decrease in biomass.