Feruloylation and structure of arabinoxylan in wheat endosperm cell walls from RNAi lines with suppression of genes responsible for backbone synthesis and decoration.
Feruloylation and structure of arabinoxylan in wheat endosperm cell walls from RNAi lines with suppression of genes responsible for backbone synthesis and decoration.
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DOI：
10.1111/pbi.12727
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发表时间：
2017-11
影响因子：
13.8
通讯作者：
Mitchell RAC
中科院分区：
文献类型：
--
作者：
Freeman J;Ward JL;Kosik O;Lovegrove A;Wilkinson MD;Shewry PR;Mitchell RAC
阿拉伯木聚糖（AX）是小麦籽粒细胞壁的主要成分（70%在淀粉胚乳中），是影响食品加工、动物饲料和蒸馏的最终用途质量的重要决定因素，也是人类饮食中膳食纤维的主要来源。AX是一种异质多糖，由可以依次用水（WE-AX）提取的级分组成，然后木聚糖酶作用（XE-AX）留下不可提取的（XU-AX）级分。我们在野生型小麦和具有降低的AX含量（TaGT 43_2 RNAi、TaGT 47_2 RNAi）或降低的与单取代木糖3-连接的阿拉伯糖（TaXAT 1 RNAi）的RNAi品系中确定了这些级分中AX的阿拉伯糖基化和阿魏酰化。我们发现，在所有RNAi株系及其对照株系中，这些组分的特征在于AX的阿魏酰化程度分别为<5、5-7和13-19 mg结合阿魏酸（g−1 AX），WE、XE和XU组分的二阿魏酸（diFA）含量分别为<0.3、1-1.7和4-5 mg（g−1 AX）。AX的量及其阿拉伯糖基化和阿魏酸化程度在XE-AX级分中比在WE-AX级分中受RNAi转基因的影响更小，并且在XU-AX级分中基本上不受影响。由于大部分diFA与XU-AX组分相关，因此对总diFA含量仅有小的影响（TaGT 43_2 RNAi、TaGT 47_2 RNAi）或无影响（TaXAT 1 RNAi）。我们的研究结果是兼容的模型，以维持细胞壁的功能，diFA保持在稳定的水平时，其他AX属性被改变。
Arabinoxylan (AX) is the major component of the cell walls of wheat grain (70% in starchy endosperm), is an important determinant of end‐use qualities affecting food processing, use for animal feed and distilling and is a major source of dietary fibre in the human diet. AX is a heterogeneous polysaccharide composed of fractions which can be sequentially extracted by water (WE‐AX), then xylanase action (XE‐AX) leaving an unextractable (XU‐AX) fraction. We determined arabinosylation and feruloylation of AX in these fractions in both wild‐type wheat and RNAi lines with decreased AX content (TaGT43_2 RNAi, TaGT47_2 RNAi) or decreased arabinose 3‐linked to mono‐substituted xylose (TaXAT1 RNAi). We show that these fractions are characterized by the degree of feruloylation of AX, <5, 5–7 and 13–19 mg bound ferulate (g−1 AX), and their content of diferulates (diFA), <0.3, 1–1.7 and 4–5 mg (g−1 AX), for the WE, XE and XU fractions, respectively, in all RNAi lines and their control lines. The amount of AX and its degree of arabinosylation and feruloylation were less affected by RNAi transgenes in the XE‐AX fraction than in the WE‐AX fraction and largely unaffected in the XU‐AX fraction. As the majority of diFA is associated with the XU‐AX fraction, there was only a small effect (TaGT43_2 RNAi, TaGT47_2 RNAi) or no effect (TaXAT1 RNAi) on total diFA content. Our results are compatible with a model where, to maintain cell wall function, diFA is maintained at stable levels when other AX properties are altered.
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影响因子：
8.8
作者：
Kosik, Ondrej;Powers, Stephen J.;Chatzifragkou, Afroditi;Prabhakumari, Parvathy Chandran;Charalampopoulos, Dimitris;Hess, Linde;Brosnan, James;Shewry, Peter R.;Lovegrove, Alison
通讯作者：
Lovegrove, Alison
影响因子：
6.1
作者：
Lu, Fachuang;Wei, Liping;Ralph, John
通讯作者：
Ralph, John
影响因子：
7.4
作者：
Pellny, Till K.;Lovegrove, Alison;Mitchell, Rowan A. C.
通讯作者：
Mitchell, Rowan A. C.
影响因子：
13.8
作者：
Harholt, Jesper;Bach, Inga C.;Scheller, Henrik V.
通讯作者：
Scheller, Henrik V.
影响因子：
3.1
作者：
ISHII, T
通讯作者：
ISHII, T