Alteration of S-adenosylhomocysteine levels affects lignin biosynthesis in switchgrass.
Alteration of S-adenosylhomocysteine levels affects lignin biosynthesis in switchgrass.
复制标题
S-腺苷高半胱氨酸水平的改变影响柳枝稷中的木质素生物合成。
DOI：
10.1111/pbi.12935
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发表时间：
2018-12
影响因子：
13.8
通讯作者：
Fu C
中科院分区：
文献类型：
--
作者：
Bai Z;Qi T;Liu Y;Wu Z;Ma L;Liu W;Cao Y;Bao Y;Fu C
由天冬氨酸合成的蛋氨酸是合成S-腺苷甲硫氨酸所必需的基本氨基酸，而腺苷甲硫氨酸是单甘醇甲基化的重要辅因子。S同型半胱氨酸作为一种竞争性的腺苷同型半胱氨酸甲基化抑制剂，在植物中对木质素生物合成的影响尚不清楚。利用RNA干扰技术分别下调了谷胱甘肽γ合成酶和S腺苷同型半胱氨酸水解酶1基因在两用饲料和生物燃料作物中的表达水平。研究了SAH对木质素生物合成的影响。我们的结果表明，PvCGS的下调改变了天冬氨酸和芳香族氨基酸的积累，降低了SAH的含量，促进了木质素的生物合成，阻碍了植物的生长。相反，PvSAHH1的下调提高了柳枝菊的SAH水平，损害了愈创木基木素和丁香基木质素的生物合成，从而显著提高了细胞壁的糖化效率。这项工作表明，SAH在柳枝菊单醇甲基化过程中起着关键作用。基因调控PvCGS或PvSAHH1的表达可以改变细胞内SAH含量和SAM/SAH比率，从而影响木质素的生物合成。因此，我们的研究表明，参与蛋氨酸代谢的基因是未来细胞壁生物工程的新的有价值的靶点。
Methionine (Met) synthesized from aspartate is a fundamental amino acid needed to produce S‐adenosylmethionine (SAM) that is an important cofactor for the methylation of monolignols. As a competitive inhibitor of SAM‐dependent methylation, the effect of S‐adenosylhomocysteine (SAH) on lignin biosynthesis, however, is still largely unknown in plants. Expression levels of Cystathionine γ‐synthase (PvCGS) and S‐adenosylhomocysteine hydrolase 1 (PvSAHH1) were down‐regulated by RNAi technology, respectively, in switchgrass, a dual‐purpose forage and biofuel crop. The transgenic switchgrass lines were subjected to studying the impact of SAH on lignin biosynthesis. Our results showed that down‐regulation of PvCGS in switchgrass altered the accumulation of aspartate‐derived and aromatic amino acids, reduced the content of SAH, enhanced lignin biosynthesis and stunted plant growth. In contrast, down‐regulation of PvSAHH1 raised SAH levels in switchgrass, impaired the biosynthesis of both guaiacyl and syringyl lignins and therefore significantly increased saccharification efficiency of cell walls. This work indicates that SAH plays a crucial role in monolignol methylation in switchgrass. Genetic regulation of either PvCGS or PvSAHH1 expression in switchgrass can change intracellular SAH contents and SAM to SAH ratios and therefore affect lignin biosynthesis. Thus, our study suggests that genes involved in Met metabolism are of interest as new valuable targets for cell wall bioengineering in future.
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影响因子：
13.8
作者：
Fu C;Sunkar R;Zhou C;Shen H;Zhang JY;Matts J;Wolf J;Mann DG;Stewart CN Jr;Tang Y;Wang ZY
通讯作者：
Wang ZY
影响因子：
7.4
作者：
Cohen, Hagai;Hacham, Yael;Amir, Rachel
通讯作者：
Amir, Rachel
DOI：
10.1079/pavsnnr20116028
发表时间：
2011-01-01
影响因子：
--
作者：
Bedon, F.;Legay, S.
通讯作者：
Legay, S.
影响因子：
13.8
作者：
Avraham, T;Badani, H;Amir, R
通讯作者：
Amir, R
影响因子：
6.2
作者：
Cohen, Hagai;Salmon, Asaf;Amir, Rachel
通讯作者：
Amir, Rachel