Li Xiao-Yuan, Liu Gui-Feng, Zeng Qing-Yin, Liu Yan-Jing
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University and Chinese Academy of Forestry, Harbin 150040, China.
Int J Mol Sci. 2025 Apr 25;26(9):4087. doi: 10.3390/ijms26094087.
species are important resources for ecological conservation and certain industry productions, and are also considered model tree species for scientific research. For tree species, in vitro plant regeneration is an important method of propagation due to the advantage of high multiplication rate. Although many molecular determinants for poplar regeneration have been investigated, the complete regulatory hierarchy network remains unclear. In this study, we tracked the temporal changes of endogenous hormone contents, physiological characteristics and transcriptional profiles during callus induction and adventitious organogenesis in a stem of L. to explore the regulatory dynamics of in vitro regeneration in poplars. The results imply that auxin may promote the formation of callus in by activating the expression of . By up-regulating the expression of , the development of callus begins to initiate apical meristem (SAM) at day 12. The cytokinin-mediated pathway regulates the adventitious shoot formation by and . The precursors of active gibberellin GA1, GA53 and GA19 were accumulated in the early stage of callus induction, and then they continued to decrease. JA may function on adventitious shoot regeneration due to its accumulation after 12 days of induction. The dominant hormonal components and regulatory factors during regeneration were identified. Based on the results, a regeneration pathway regulated by auxin and cytokinin for poplars is proposed. The key regulators identified in this study will accelerate the exploration and understanding of the asexual reproduction mechanism of poplar trees.
物种是生态保护和某些工业生产的重要资源，也被视为科学研究的模式树种。对于树木物种而言，由于其繁殖率高的优势，离体植株再生是一种重要的繁殖方法。尽管已经对杨树再生的许多分子决定因素进行了研究，但完整的调控层次网络仍不清楚。在本研究中，我们追踪了L.茎在愈伤组织诱导和不定器官发生过程中内源激素含量、生理特征和转录谱的时间变化，以探索杨树离体再生的调控动态。结果表明，生长素可能通过激活……的表达来促进L.中愈伤组织的形成。通过上调……的表达，愈伤组织的发育在第12天开始启动顶端分生组织（SAM）。细胞分裂素介导的途径通过……和……调节不定芽的形成。活性赤霉素GA1、GA53和GA19的前体在愈伤组织诱导早期积累，然后持续下降。茉莉酸（JA）可能由于其在诱导12天后的积累而在不定芽再生中起作用。确定了再生过程中的主要激素成分和调控因子。基于这些结果，提出了一条由生长素和细胞分裂素调控的杨树再生途径。本研究中确定的关键调控因子将加速对杨树无性繁殖机制的探索和理解。
