AUTHOR=Guo Huiyan , Bi Xinyue , Wang Zhiping , Jiang Dong , Cai Ming , An Mengnan , Xia Zihao , Wu Yuanhua 

TITLE=Reactive oxygen species-related genes participate in resistance to cucumber green mottle mosaic virus infection regulated by boron in Nicotiana benthamiana and watermelon

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1027404

DOI=10.3389/fpls.2022.1027404

ISSN=1664-462X

ABSTRACT=<p>Cucumber green mottle mosaic virus (CGMMV) infection causes acidification and rot of watermelon flesh, resulting in serious economic losses. It is widely reported the interaction relationship between boron and reactive oxygen species (ROS) in regulating normal growth and disease resistance in plants. Our previous results demonstrated that exogenous boron could improve watermelon resistance to CGMMV infection. However, the roles of ROS-related genes regulated by boron in resistance to CGMMV infection are unclear. Here, we demonstrated that CGMMV symptoms were alleviated, and viral accumulations were decreased by boron application in <italic>Nicotiana benthamiana</italic>, indicating that boron contributed to inhibiting CGMMV infection. Meanwhile, we found that a number of differentially expressed genes (DEGs) associated with inositol biosynthesis, ethylene synthesis, Ca<sup>2+</sup> signaling transduction and ROS scavenging system were up-regulated, while many DEGs involved in ABA catabolism, GA signal transduction and ascorbic acid metabolism were down-regulated by boron application under CGMMV infection. Additionally, we individually silenced nine ROS-related genes to explore their anti-CGMMV roles using a tobacco rattle virus (TRV) vector. The results showed that <italic>NbCat1</italic>, <italic>NbGME1</italic>, <italic>NbGGP</italic> and <italic>NbPrx Q</italic> were required for CGMMV infection, while <italic>NbGST</italic> and <italic>NbIPS</italic> played roles in resistance to CGMMV infection. The similar results were obtained in watermelon by silencing of <italic>ClCat</italic>, <italic>ClPrx</italic> or <italic>ClGST</italic> expression using a pV190 vector. This study proposed a new strategy for improving plant resistance to CGMMV infection by boron-regulated ROS pathway and provided several target genes for watermelon disease resistance breeding.</p>