恒频超声处理有助于提高种子萌发。然而,变频超声处理对玉米种子萌发的影响鲜有报道。在这项研究中,玉米种子暴露于20-40kHz超声波下40s。玉米种子的发芽率和胚根长度分别增加了10.4%和230.5%。超声波处理也显著增加了酸性蛋白酶,α-淀粉酶,β-淀粉酶含量下降96.4%,73.8%,和49.1%,分别。转录组分析表明,在超声处理组和对照组中发现了11,475个差异表达基因(DEGs),包括5695个上调和5780个下调。超声处理后,DEGs之间的代谢途径和转录因子(TFs)显着丰富。这包括新陈代谢和遗传信息处理,也就是说,核糖体,蛋白酶体,和丙酮酸代谢,倍半萜,三萜类,和苯丙素生物合成,和氧化磷酸化,以及NAC中的转录因子,MYB,bHLH,WRKY,AP2,bZIP,和ARF家庭。变频超声处理增加生长素,赤霉素,和水杨酸下降了5.5%,37.3%,和28.9%,分别。脱落酸显著下降33.2%。相关的DEGs在不同程度上上调和下调。盐胁迫(NaCl溶液)的非生物胁迫条件下的种子萌发,干旱(PEG溶液),促进了超声处理下的内涝(水饱和砂层),胚根长度显著增加了30.2%,30.5%,和27.3%,发芽率分别为14.8%,20.1%,和21.6%,分别。这些发现为超声促进玉米种子萌发的机制提供了新的见解。
Constant-frequency ultrasonic treatment helped to improve seed germination. However, variable-frequency ultrasonic treatment on maize seed germination were rarely reported. In this study, maize seeds were exposed to 20-40 kHz ultrasonic for 40 s. The germination percentage and radicle length of maize seeds increased by 10.4% and 230.5%. Ultrasonic treatment also significantly increased the acid protease, α-amylase, and β-amylase contents by 96.4%, 73.8%, and 49.1%, respectively. Transcriptome analysis showed that 11,475 differentially expressed genes (DEGs) were found in the ultrasonic treatment and control groups, including 5,695 upregulated and 5,780 downregulated. Metabolic pathways and transcription factors (TFs) were significantly enriched among DEGs after ultrasonic treatment. This included metabolism and genetic information processing, that is, ribosome, proteasome, and pyruvate metabolism, sesquiterpenoid, triterpenoid, and phenylpropanoid biosynthesis, and oxidative phosphorylation, as well as transcription factors in the NAC, MYB, bHLH, WRKY, AP2, bZIP, and ARF families. Variable-frequency ultrasonic treatment increased auxin, gibberellin, and salicylic acid by 5.5%, 37.3%, and 28.9%, respectively. Abscisic acid significantly decreased by 33.2%. The related DEGs were upregulated and downregulated to varying degrees. Seed germination under the abiotic stress conditions of salt stress (NaCl solution), drought (PEG solution), and waterlogging (water-saturated sand bed) under ultrasonic treatment were promoted, radicle length was significantly increased by 30.2%, 30.5%, and 27.3%, respectively; and germination percentage by 14.8%, 20.1%, and 21.6%, respectively. These findings provide new insight into the mechanisms through ultrasonic to promote maize seed germination.