Li Shuang, Yin Yanling, Chen Jianmin, Cui Xinyu, Fu Jinmin
Coastal Salinity Tolerant Grass Engineering and Technology Research Center, Ludong University, Yantai, China.
PeerJ. 2024 Feb 29;12:e16985. doi: 10.7717/peerj.16985. eCollection 2024.
Tillering/branching pattern plays a significant role in determining the structure and diversity of grass, and trimming has been found to induce tillering in turfgrass. Recently, it has been reported that hydrogen peroxide (HO) regulates axillary bud development. However, the role of HO in trimming-induced tillering in bermudagrass, a kind of turfgrass, remains unclear. Our study unveils the significant impact of trimming on promoting the sprouting and growth of tiller buds in stolon nodes, along with an increase in the number of tillers in the main stem. This effect is accompanied by spatial-temporal changes in cytokinin and sucrose content, as well as relevant gene expression in axillary buds. In addition, the partial trimming of new-born tillers results in an increase in sucrose and starch reserves in their leaves, which can be attributed to the enhanced photosynthesis capacity. Importantly, trimming promotes a rapid HO burst in the leaves of new-born tillers and axillary stolon buds. Furthermore, exogenous application of HO significantly increases the number of tillers after trimming by affecting the expression of cytokinin-related genes, bolstering photosynthesis potential, energy reserves and antioxidant enzyme activity. Taken together, these results indicate that both endogenous production and exogenous addition of HO enhance the inductive effects of trimming on the tillering process in bermudagrass, thus helping boost energy supply and maintain the redox state in newly formed tillers.
分蘖/分枝模式在决定禾本科植物的结构和多样性方面起着重要作用，并且已发现修剪可诱导草坪草分蘖。最近，有报道称过氧化氢（H₂O₂）调节腋芽发育。然而，H₂O₂在一种草坪草——狗牙根修剪诱导分蘖中的作用仍不清楚。我们的研究揭示了修剪对促进匍匐茎节上分蘖芽的萌发和生长具有显著影响，同时主茎上的分蘖数量增加。这种效应伴随着细胞分裂素和蔗糖含量以及腋芽中相关基因表达的时空变化。此外，对新生分蘖进行部分修剪会导致其叶片中蔗糖和淀粉储备增加，这可归因于光合作用能力的增强。重要的是，修剪促进新生分蘖叶片和腋生匍匐茎芽中H₂O₂的快速爆发。此外，外源施加H₂O₂通过影响细胞分裂素相关基因的表达、增强光合作用潜力、能量储备和抗氧化酶活性，显著增加修剪后的分蘖数量。综上所述，这些结果表明，内源性产生和外源性添加H₂O₂均增强了修剪对狗牙根分蘖过程的诱导作用，从而有助于增加能量供应并维持新形成分蘖中的氧化还原状态。
