Nano-ZnO Promotes Adventitious Root Formation of Apple Stock M26

Wan Ran; Zhang Jinming; Liu Jun; Zhang Mengxi; Dong Ao; Wang Xiaojing; Qiao Ming; Shi Jiangli; Zheng Xianbo

doi:10.15933/j.cnki.1004-3268.2026.08.011

Abstract：This study aimed to investigate the effects of zinc oxide nanoparticles(ZnO NPs)on adventitious root formation in apple rootstock M26,so as to provide a novel strategy for efficient tissue culture-based rapid propagation of apple seedlings.Using tissue-cultured seedlings of apple rootstock M26 as the experimental material,different nanomaterial treatment groups(ZnO NPs,TiO₂ NPs,etc.)and a conventional IBA rooting medium as control group(CK)were established.Through phenotypic observation,physiological and biochemical index measurements,and the related gene expression analysis,the effects of ZnO NPs on adventitious root formation were systematically studied.The results showed that ZnO NPs treatment significantly improved the rooting rate,root length,and root surface area of M26,while also promoting biomass accumulation in tissue-cultured seedlings.Additionally,ZnO NPs enhanced chlorophyll synthesis and the uptake of Zn and K.For instance,Zn content increased by approximately 12.4-fold in shoots and 6.5-fold in roots,while K content increased by 16.4％and 9.0％,respectively.Furthermore,auxin pathway genes(MdAUX1)were significantly upregulated at 6 d,while transcription factor genes(MdLBD16,MdWOX5)were upregulated to 1.3-and 1.8-fold of the CK level,respectively,whereas the negative regulator MdTCP17 was significantly downregulated during 2-6 d post treatment.ZnO NPs significantly promoted adventitious root formation in apple rootstock M26 by improving nutrient uptake,enhancing photosynthesis,and modulating the expression of key genes.