Work

Trans-cinnamic acid coordinates PAL repression and C4H induction to modulate lignification in bamboo

Year: 2025

Type: article

Abstract: Lignin deposition in rapidly elongating bamboo culm requires precise metabolic coordination; however, regulatory mechanisms balancing phenylpropanoid precursor supply and demand remain unclear. Here, we identify a self-regulating PAL-C4H module in bamboo where the pathway intermediate trans-cinnamic acid (t-CA) acts bidirectionally. Transcriptomic and biochemical analyses revealed that t-CA simultaneously activates downstream lignin biosynthesis by upregulating cinnamate 4-hydroxylase (PeC4H1/2) gene expression and enzymatic activity, and suppresses upstream phenylalanine ammonia-lyase (PAL) through both transcriptional (PePAL10/11 repression) and posttranslational (PeKFB9-mediated ubiquitination) controls. This feedback loop ensures resource prioritization for secondary cell wall formation during culm maturation, as evidenced by increased lignin content in t-CA-treated seedlings. Evolutionary analyses further suggest bamboo-specific optimization of this regulatory paradigm to support bamboo's unique growth kinetics. Our findings redefine flux control mechanisms in bamboo lignification and provide actionable targets for precision breeding of bamboo as a substitute for plastic.

Source: PLANT PHYSIOLOGY

DOI: 10.1093/plphys/kiaf472

Authors: Qingnan Wang, Hui Li, Xiaolin Di, Xiaoming Zou, Zhimin Gao, Huayu Sun

Institutions: International Bamboo and Rattan Organization, International Center for Bamboo and Rattan

Language: English

Topic: Plant Gene Expression Analysis

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: National Natural Science Foundation of China, International Centre for Bamboo and Rattan

Awards: G6513228257, G859642671