Zinc oxide nanoparticles alleviated vanadium-induced inhibition by regulating plant hormone signal transduction and phenylpropanoid biosynthesis in maize seedlings (Zea may L.)
Zhe Wang, Chengjing Tang, Xue Mi, Debao Yao, Zhikun Chen, Chao‐Yu Guo, Yongping Zhao, Xiaodong Xue, Weidong Chang, Yanhua Li
Abstract
Our efforts were to identify the role of zinc oxide nanoparticles (ZnO-NPs) on the growth of maize (Zea may L.) under vanadium (V) stress. Transcriptome analysis was performed on maize leaves subjected to CK, V, and V+ZnO treatments. It was found that the application of ZnO-NPs significantly reduces V accumulation and toxicity in maize. A total of 5441 and 3003 differentially expressed genes (DEGs) were identified in the CK vs. V and V+ZnO vs. V comparisons, respectively. Of these detected genes, 3016 DEGs were specific to CV vs. V, and 608 DEGs were specific to V+ZnO vs V, respectively. These genes were primarily involved in plant hormone signal transduction and phenylpropanoid biosynthesis pathways. Under V treatment, ZnO-NPs caused an up-regulation of SAUR, AUX/IAA, ARRs, GID1, and BRIIs, which resulted in high levels of IAA, CTK, GA, BRs, and JAs in maize seedlings compared to those without ZnO-NPs. The addition of ZnO-NPs also leads to a significant decrease in total phenolics and lignin contents in maize seedlings by down-regulating CCR, HCT, CAD, 4CL, and C4H genes compared to those without ZnO-NPs. Overall, the findings suggest that ZnO-NPs can improve V-induced growth suppression by changing the expression of selected genes and constitute a simple and efficient strategy for alleviating V toxicity in high-V soils.