Zhang Junbo, Shi Man, Zhu Chenglei, Yang Kebin, Li Quan, Song Xiaoming, Gao Zhimin, Cao Tingting, Zhu Dezheng, Song Xinzhang
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Wusu Street No. 666, Lin'an District, Hangzhou 311300, China.
Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Desheng Middle Road No. 298, Jianggan District, Hangzhou 310021, China.
Hortic Res. 2025 Feb 25;12(6):uhaf062. doi: 10.1093/hr/uhaf062. eCollection 2025 Jun.
Rapid growth of Moso bamboo () shoots (offspring ramet) is primarily fuelled by nitrogen (N) derived from parent ramet and absorbed by rhizome roots. However, the extent to which each N source supports the growth of offspring ramet and the underlying molecular mechanisms of N transport remain unclear. Here, clonal fragments consisting of a parent ramet, an offspring ramet, and an interconnected rhizome were established in a Moso bamboo forest. Additionally, N isotope tracing and transcriptome profiling were conducted concurrently to quantify the N contribution from the parent ramet and rhizome roots to the offspring ramet, and to reveal the molecular mechanisms underlying N transport during rapid growth (i.e. early, peak, branching, and leafing stages). The N acquisition strategy of offspring ramet shifted from being primarily provided by the parent ramet (72.53%) during early stage to being predominantly absorbed by rhizome roots (69.85%) during the leafing stage. Approximately equal N contributions (45.82%-54.18%) from the parent ramet and rhizome roots were observed during peak and branching stages. was identified as a key gene for N transport, being most closely correlated with N content. Biomolecular assays demonstrated that PeHDZ23987 could activate the expression of via two types of HD-motifs. Overexpression of and significantly enhanced N starvation tolerance in transgenic rice with significantly improved N uptake efficiency. Our findings clarify the pattern and mechanisms of N supply for the rapid growth of Moso bamboo offspring ramet and provide transcriptomic evidence for long-distance N transport between clonal ramets.
毛竹（）笋（分株后代）的快速生长主要由来自母株并由根茎根吸收的氮（N）提供养分。然而，每种氮源对分株后代生长的支持程度以及氮运输的潜在分子机制仍不清楚。在此，在毛竹林中建立了由母株、分株后代和相连根茎组成的克隆片段。此外，同时进行了氮同位素示踪和转录组分析，以量化母株和根茎根对分株后代的氮贡献，并揭示快速生长（即早期、高峰期、分枝期和展叶期）期间氮运输的分子机制。分株后代的氮获取策略从早期主要由母株提供（72.53%）转变为展叶期主要由根茎根吸收（69.85%）。在高峰期和分枝期，观察到母株和根茎根的氮贡献大致相等（45.82%-54.18%）。被鉴定为氮运输的关键基因，与氮含量相关性最高。生物分子分析表明，PeHDZ23987可以通过两种类型的HD基序激活的表达。和的过表达显著增强了转基因水稻对氮饥饿的耐受性，氮吸收效率显著提高。我们的研究结果阐明了毛竹分株后代快速生长的氮供应模式和机制，并为克隆分株之间的长距离氮运输提供了转录组证据。
