Wood forming tissue-specific expression of PdSuSy and HCHL increases holocellulose content and improves saccharification in Populus

• 作者: Yang Zhang Hua Xu Yingzhen Kong Jiawen Hua Xianfeng Tang Yamei Zhuang Yue Bai Gongke Zhou Guohua Chai
• 来源期刊: 林业研究（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: ORIGINAL PAPERS
• 页码范围: 1681-1688
• 页数: 8页
• 语种: 英文

摘要

Development of strategies to deconstruct ligno-cellulosic biomass in tree species is essential for biofuels and biomaterials production. We applied a wood forming tissue-specific system in a hybrid poplar to express both PdSuSy (a sucrose synthase gene from Populus deltoides × P. euramericana that has not been functionally characterized) and HCHL (the hydroxycinnamoyl-CoA hydratase-lyase gene from Pseudomonas fluorescens, which inhibits lignin polymerization in Arabidopsis ). The PdSuSy - HCHL over-expression poplars correspondingly driven by the promoters of Arabidopsis AtCesA7 and AtC4H resulted in a significant increase in cellulose (> 8％), xylan (> 12％) and glucose (> 29％) content, accompanying a reduction in galacturonic acid (> 36％) content, compared to control plants. The sac-charification efficiency of these overexpression poplars was dramatically increased by up to 27％, but total lignin con-tent was unaffected. These transgenic poplars showed inhib-ited growth characteristics, including > 16％ reduced plant height, > 10％ reduced number of internodes, and > 18％ reduced fresh weight after growth of 4 months, possibly due to relatively low expression of HCHL in secondary xylem. Our results demonstrate the structural complexity and inter-action of the cell wall polymers in wood tissue and outline a potential method to increase biomass saccharification in woody species.