Cloning and Disease Resistance Analysis of the Maize ZmBON3 Gene

(1) Corn is the most widely planted food crop, feed crop, and economic crop in the world, and plays an important role in agricultural production and national economy development. The copine gene, also known as the BONZAI gene, encodes a Ca2+-dependent phospholipid membrane binding protein that is widely present in eukaryotes. It has been found that the copine protein is a negative regulator of disease resistance regulation and plays a key role in plants' disease resistance response. In this study, the Agrobacterium-tumefacien-mediated method was used to successfully obtain T2 generation ZmBON3-gene-overexpressing plants and gene-edited plants. Related phenotypes and molecular identification showed that the disease resistance of overexpression plants was significantly reduced, and the disease resistance of gene-edited plants was significantly increased, which verified that the ZmBON3 gene was a negative regulatory gene. By detecting the physiological indexes related to defense, it was found that the content of H2O2 and the enzyme active water of CAT, POD, SOD, and PAL in ZmBON3-gene-edited plants was higher than those in the control plants and ZmBON3-gene-overexpressing plants, and the content of H2O2 and CAT, POD, and SOD in ZmBON3-gene-overexpressing plants was significantly higher than that in the control plants and ZmBON3-gene-overexpressing plants. The enzyme activity of PAL was the lowest. By detecting the expression of key genes of defense-related signaling pathways, it was found that ZmBON3 may be involved in the related defense processes mediated by the R gene, SA pathway, JA pathway, and ABA pathway. In addition, ZmBON3-geneedited plants showed obvious dwarf phenomenon at the seedling stage, but this did not affect the ear length, axis diameter, ear row number, and grain color.