Laboratory of Plant Biochemistry, State University of Maringá, Av. Colombo, 5790, 87020-900, Maringá, PR, Brazil.
Ghent University, Department of Plant Biotechnology and Bioinformatics and VIB Center for Plant Systems Biology, Ghent, Belgium.
Plant Physiol Biochem. 2022 May 1;178:12-19. doi: 10.1016/j.plaphy.2022.02.018. Epub 2022 Feb 28.
Lignin is a technological bottleneck to convert polysaccharides into fermentable sugars, and different strategies of genetic-based metabolic engineering have been applied to improve biomass saccharification. Using maize seedlings grown hydroponically for 24 h, we conducted a quick non-transgenic approach with five enzyme inhibitors of the lignin and tricin pathways. Two compounds [3,4-(methylenedioxy)cinnamic acid: MDCA and 2,4-pyridinedicarboxylic acid: PDCA] revealed interesting findings on root growth, lignin composition, and saccharification. By inhibiting hydroxycinnamoyl-CoA ligase, a key enzyme of phenylpropanoid pathway, MDCA decreased the lignin content and improved saccharification, but it decreased root growth. By inhibiting flavone synthase, a key enzyme of tricin biosynthesis, PDCA decreased total lignin content and improved saccharification without affecting root growth. PDCA was three-fold more effective than MDCA, suggesting that controlling lignin biosynthesis with enzymatic inhibitors may be an attractive strategy to improve biomass saccharification.
木质素是将多糖转化为可发酵糖的技术瓶颈，已应用不同的基于遗传的代谢工程策略来提高生物质糖化效率。我们利用水培生长 24 小时的玉米幼苗，采用 5 种木质素和木樨草素途径的酶抑制剂进行快速非转基因方法。两种化合物[3,4-（亚甲二氧基）肉桂酸：MDCA 和 2,4-吡啶二羧酸：PDCA]对根系生长、木质素组成和糖化作用有显著影响。通过抑制苯丙氨酸途径的关键酶羟基肉桂酰辅酶 A 连接酶，MDCA 降低了木质素含量并提高了糖化效率，但降低了根系生长。通过抑制木樨草素生物合成的关键酶黄酮合酶，PDCA 降低了总木质素含量并提高了糖化作用，而不影响根系生长。PDCA 的效果比 MDCA 高出三倍，这表明用酶抑制剂控制木质素生物合成可能是提高生物质糖化效率的一种有吸引力的策略。
