Huayu Sun

As the Earth’s resources are increasingly being depleted, fossil resources such as oil and natural gas are becoming scarcer, making renewable resources the focus of this Editorial

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 post-translational (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.

Bamboo gene science has witnessed significant advancements over the past two decades, driven by breakthroughs in gene cloning, marker-assisted breeding, sequencing, gene transformation, and gene editing technologies. These developments have not only enhanced our understanding of bamboo’s genetic diversity and adaptability but also provided critical tools for its genetic improvement. Compared to other crops, bamboo faces unique challenges, including its long vegetative growth cycle, environmental dependency, and limited genetic transformation efficiency. Then, the launch of China’s “Bamboo as a Substitute for Plastic” initiative in 2022, supported by the International Bamboo and Rattan Organization, has opened new opportunities for bamboo gene science as well as for bamboo production systems. This policy framework has spurred research into bamboo genetic regulation, fiber-oriented recombination, and green separation technologies, aiming to develop sustainable alternatives to plastic. Future research directions include overcoming bamboo’s environmental limitations, improving genetic transformation efficiency, and deciphering the mechanisms behind its flowering. By addressing these challenges, bamboo genetic science can enhance its economic and ecological value, contributing to global sustainability goals and the “dual-carbon” strategy.

Bamboo, renowned as the fastest‐growing plant globally, matures within an astonishingly short period of 40–50 days from shoots, reaching heights of 10–20 meters. Moreover, it can be harvested for various uses within 3–5 years. Bamboo exhibits exceptional mechanical properties, characterized by high hardness and flexibility, largely attributed to its lignin content. Phenylalanine ammonia‐lyase (PAL) catalyzes the crucial initial step in lignin biosynthesis, but its precise role in bamboo lignification processes remains elusive. Thus, elucidating the functions of PAL genes in bamboo lignification processes is imperative for understanding its rapid growth and mechanical strength. Here, we systematically identified and classified PAL genes in Moso bamboo, ensuring nomenclature consistency across prior studies. Subsequently, we evaluated PAL gene expression profiles using publicly available transcriptome data. The downregulation of PePALs expression in Moso bamboo through in planta gene editing resulted in a decrease in PAL activity and a subsequent reduction in lignin content. In contrast, overexpression of PePAL led to enhanced PAL activity and an increase in lignin content. These findings highlight the critical role of PAL in the lignin biosynthesis process of Moso bamboo, which will help to unravel the mechanism underpinning bamboo's rapid growth and mechanical strength, with a specific emphasis on elucidating the functions of PAL genes.

Bamboo breeding strategies are essential in realizing “Bamboo as a Substitute for Plastic (BASP)”. This review article aims to explore the crucial role of breeding strategies in achieving the substitution of plastic products with bamboo as outlined under the BASP Initiative. Firstly, we address the issue of plastic pollution, along with the background of reducing the market share and demand for plastic products. It categorizes the types of bamboo products that can fully or partially replace plastic products in various categories, such as daily necessities, building materials, and industrial products. Then, we investigate which bamboo species can replace which plastic products and propose the need for bamboo improvement. Furthermore, it presents data from positioning observation research stations for bamboo forest ecosystems in China and outlines the essential traits necessary for bamboo substitution, including characteristics like long internode length, extended fiber length, thick culm wall, and optimal cellulose-to-lignin content ratio, among others. Finally, we discuss breeding methods and genetic improvement as key strategies to achieve bamboo substitution and suggest the potential of enhancing bamboo traits to serve as a viable replacement source for plastics. This comprehensive approach aims to enhance bamboo’s growth features and physical properties to meet the criteria for substituting bamboo for plastics effectively.

Long-distance transport or systemic silencing effects of exogenous biologically active RNA molecules in higher plants have not been reported. Here, we report that cationized bovine serum albumin (cBSA) avidly binds double-stranded beta-glucuronidase RNA (dsGUS RNA) to form nucleic acid–protein nanocomplexes. In our experiments with tobacco and poplar plants, we have successfully demonstrated systemic gene silencing effects of cBSA/dsGUS RNA nanocomplexes when we locally applied the nanocomplexes from the basal ends of leaf petioles or shoots. We have further demonstrated that the cBSA/dsGUS RNA nanocomplexes are highly effective in silencing both the conditionally inducible DR5-GUS gene and the constitutively active 35S-GUS gene in leaf, shoot, and shoot meristem tissues. This cBSA/dsRNA delivery technology may provide a convenient, fast, and inexpensive tool for characterizing gene functions in plants and potentially for in planta gene editing.