CsPrx25, a class III peroxidase in Citrus sinensis, confers resistance to citrus bacterial canker through the maintenance of ROS homeostasis and cell wall lignification

Abstract

Citrus bacterial canker (CBC) results from Xanthomonas citri subsp. citri (Xcc) infection and poses a grave threat to citrus production. Class III peroxidases (CIII Prxs) are key proteins to the environmental adaptation of citrus plants to a range of exogenous pathogens, but the role of CIII Prxs during plant resistance to CBC is poorly defined. Herein, we explored the role of CsPrx25 and its contribution to plant defenses in molecular detail. Based on the expression analysis, CsPrx25 was identified as an apoplast-localized protein that is differentially regulated by Xcc infection, salicylic acid, and methyl jasmone acid in the CBC-susceptible variety Wanjincheng (C. sinensis) and the CBC-resistant variety Calamondin (C. madurensis). Transgenic Wanjincheng plants overexpressing CsPrx25 were generated, and these transgenic plants exhibited significantly increased CBC resistance compared with the WT plants. In addition, the CsPrx25-overexpressing plants displayed altered reactive oxygen species (ROS) homeostasis accompanied by enhanced H2O2 levels, which led to stronger hypersensitivity responses during Xcc infection. Moreover, the overexpression of CsPrx25 enhanced lignification as an apoplastic barrier for Xcc infection. Taken together, the results highlight how CsPrx25-mediated ROS homeostasis reconstruction and cell wall lignification can enhance the resistance of sweet orange to CBC.

The Cysteine-Rich Peptide Snakin-2 Negatively Regulates Tubers Sprouting through Modulating Lignin Biosynthesis and H2O2 Accumulation in Potato

“…It was also found that the germination rate of prx2prx25 mutant seeds is higher than that of wild-type seeds in Arabidopsis , and mainly because peroxidase affects the polymerization and the level of lignin [ 17 ]. Meanwhile, in Citrus sinensis, the overexpression of CsPrx25 enhanced H 2 O 2 levels and cell wall lignification [ 46 ]. In SN2-RNAi potato, the high lignin level resulted in periderm collapse and was more conducive to tuber sprouting, and CoIP-MS and yeast two-hybrid analysis showed a strong interaction between peroxidases and StSN2, indicating that StSN2 regulated lignin synthesis by interacting with peroxidases ( Figure 6 , Table S5 ).…”

Effects of Phytohormone-Producing Rhizobacteria on Casparian Band Formation, Ion Homeostasis and Salt Tolerance of Durum Wheat

“…However, the formation of Casparian bands in relation to bacterial action on plants was considered only as a mechanism preventing the entry of pathogenic bacteria into plants [ 21 ]. It was shown that overexpression of class III peroxidase enhanced lignification as an apoplastic barrier for infection [ 22 ]. Nevertheless, the possible promotion of apoplast barrier formation by bacteria as a mechanism of a bacterium-induced increase in salt resistance has never been addressed.…”

Efficacy of Dimethyl Trisulfide on the Suppression of Ring Rot Disease Caused by Botryosphaeria dothidea and Induction of Defense-Related Genes on Apple Fruits

“…GLU enhances the tolerant of rough lemon rootstock against foot rot (Sandhu et al, 2019), improves the inhibition of rice against Rhizoctonia solani (Kumar et al, 2018), reduces the rice sheath blight (Kaur et al, 2021), and confers tea tree resistance against blister blight disease (Singh et al, 2018). POD is involved in the resistance response of coffee varieties to Colletotrichum kahawae (Diniz et al, 2019), potato to P. infestans , Arabidopsis thaliana to Botrytis cinerea, Colletotrichum higginsianum, and Pectobacterium carotovorum (Zhao et al, 2019), Citrus sinensis to citrus bacterial canker (Li et al, 2020). CAT contributes maize to resistance against maize chlorotic mottle virus infection (Jiao et al, 2021), Nicotiana tabacum against Chilli veinal mottle virus infection (Yang T. et al, 2020).…”