Identification and suppression of the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase in Zea mays L.
Identification and suppression of the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase in Zea mays L.
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DOI：
10.1111/tpj.12510
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发表时间：
2014-06
期刊：
影响因子：
--
通讯作者：
Frost KE
中科院分区：
文献类型：
--
作者：
Marita JM;Hatfield RD;Rancour DM;Frost KE
禾本科植物，如玉米，其细胞壁中含有相对较高水平的p-香豆酸(PCA)。PCA结合到细胞壁被认为是由于一种将PCA偶联到单醇的羟基肉桂酰基转移酶。为了了解PCA在玉米发育中的作用，从玉米茎中分离和纯化了p-香豆酰辅酶A：羟基肉桂醇转移酶(PCAT)。纯化的PCAT经部分胰酶消化后，用串联质谱仪对其进行测序。对获得的多肽序列进行了TBLASTN分析，鉴定了一个编码从纯化的酶中获得的所有多肽序列的全长玉米cDNA克隆。获得该克隆，并将其用于构建抑制玉米PCAT表达的RNAi载体。在这里，我们描述了抑制玉米PCAT的效果。利用一种新的快速分析平台对转基因玉米幼苗叶片进行初步筛选，以鉴定PCA含量降低的植株。利用这种筛选方法，对发育完全的植株的成熟叶片进行了分析，证实了植物发育过程中PCA水平的降低。对成熟转基因茎叶分离细胞壁的完整分析表明，木质素水平没有变化，但PCA水平下降，木质素组成发生变化。PCA水平最低的转基因植株木质素中丁香基单位的水平降低。因此，改变玉米中PCAT的表达水平会导致木质素成分的改变，但似乎不会改变细胞壁中存在的木质素总量。
Grasses, such as Zea mays L. (maize), contain relatively high levels of p-coumarates (pCA) within their cell walls. Incorporation of pCA into cell walls is believed to be due to a hydroxycinnamyl transferase that couples pCA to monolignols. To understand the role of pCA in maize development, the p-coumaroyl CoA:hydroxycinnamyl alcohol transferase (pCAT) was isolated and purified from maize stems. Purified pCAT was subjected to partial trypsin digestion, and peptides were sequenced by tandem mass spectrometry. TBLASTN analysis of the acquired peptide sequences identified a single full-length maize cDNA clone encoding all the peptide sequences obtained from the purified enzyme. The cDNA clone was obtained and used to generate an RNAi construct for suppressing pCAT expression in maize. Here we describe the effects of suppression of pCAT in maize. Primary screening of transgenic maize seedling leaves using a new rapid analytical platform was used to identify plants with decreased amounts of pCA. Using this screening method, mature leaves from fully developed plants were analyzed, confirming reduced pCA levels throughout plant development. Complete analysis of isolated cell walls from mature transgenic stems and leaves revealed that lignin levels did not change, but pCA levels decreased and the lignin composition was altered. Transgenic plants with the lowest levels of pCA had decreased levels of syringyl units in the lignin. Thus, altering the levels of pCAT expression in maize leads to altered lignin composition, but does not appear to alter the total amount of lignin present in the cell walls.
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影响因子：
3.8
作者：
GRABBER, JH;HATFIELD, RD;AMRHEIN, N
通讯作者：
AMRHEIN, N
影响因子：
3.6
作者：
Kim, Hoon;Ralph, John;Akiyama, Takuya
通讯作者：
Akiyama, Takuya
DOI：
10.1093/bioinformatics/btq662
发表时间：
2011-02-01
期刊：
Bioinformatics (Oxford, England)
影响因子：
--
作者：
Benkert P;Biasini M;Schwede T
通讯作者：
Schwede T
影响因子：
3
作者：
Arvidsson S;Kwasniewski M;Riaño-Pachón DM;Mueller-Roeber B
通讯作者：
Mueller-Roeber B
影响因子：
5.8
作者：
Arnold, K;Bordoli, L;Schwede, T
通讯作者：
Schwede, T