Disruption of the primary salicylic acid hydroxylases in rice enhances broad‐spectrum resistance against pathogens

Abstract

Salicylic acid (SA) is a crucial hormone involved in plant immunity. Rice (Oryza sativa) maintains high SA levels that are not induced by pathogens. However, the roles of SA in rice immunity and yield remain largely unknown. Here, we identified SA 5-hydroxylases 1 (OsS5H1) and 2 (OsS5H2) as the primary enzymes engaged in catalysing SA to 2,5-dihydroxybenzoic acid (2,5-DHBA) in rice. SA levels were significantly increased in the oss5h mutants, while they were dramatically decreased in the OsS5H1 and OsS5H2 overexpression lines. The mutants were resistant, whereas the overexpression lines were susceptible to Pyricularia oryzae and Xanthomonas oryzae pv. Oryzae. Moreover, the pathogen-associated molecular patterns-triggered immunity responses, including reactive oxygen species burst and callose deposition, were enhanced in all the mutants and compromised in the overexpression lines. Quantification of the agronomic traits of the oss5h mutants grown in the paddy fields demonstrated that the grain number per panicle was decreased as the SA levels increased; however, the tiller number and grain size were enhanced, resulting in no significant yield penalty. Collectively, we reveal that mildly increasing SA content in rice can confer broad-spectrum resistance without yield penalty and put new insights into the roles of SA in immunity and growth.

The Emerging Role of 2OGDs as Candidate Targets for Engineering Crops with Broad-Spectrum Disease Resistance

“…This implies that these genes may be candidate targets for engineering crops with enhanced resistance to pathogens ( Figure 2 a). Until now, the CRISPR/Cas9-mediated mutation of a DMR6 ortholog has conferred BSR in tomato and rice [ 59 , 64 , 65 , 66 ]. Intriguingly, the disruption of the DMR6 ortholog does not influence the yield per plant of tomato and rice [ 59 , 65 ].…”

“…Until now, the CRISPR/Cas9-mediated mutation of a DMR6 ortholog has conferred BSR in tomato and rice [ 59 , 64 , 65 , 66 ]. Intriguingly, the disruption of the DMR6 ortholog does not influence the yield per plant of tomato and rice [ 59 , 65 ]. Moreover, elevated resistance to a single pathogen has been reported in banana, sweet basil, and potato via the inactivation of a DMR6 ortholog by the CRISPR/Cas9 system [ 58 , 60 , 63 ].…”

“…In addition, OsSAH2 and OsSAH3 were recently reported to negatively regulate the rice resistance to Magnaporthe oryzae ( M. oryzae ), Xanthomonas oryzae pv. Oryzae , Bipolaris oryzae , and Rhizoctonia solani [ 64 , 65 , 66 ].…”

Transcriptional Analysis of Tea Plants (Camellia sinensis) in Response to Salicylic Acid Treatment

“…SA is an indispensable hormone involved in plant immunity, and SA homeostasis in plants determines the broad-spectrum and durable resistance to pathogens and diseases. , In our study, we explored the effects of exogenous SA on the secondary metabolic pathways in tea plants. It was found that SA treatment inhibited the expression of genes in the phenylpropanoid and flavonoid pathway but promoted the lignin metabolic pathway (Figure ).…”

Xanthomonas oryzaepv.oryzaetype-III effector TAL9b targets a broadly conserved disease susceptibility locus to promote pathogenesis in rice

“…OsS5H/FNS-03g was reported by independent studies to have either S5H or FNS activities (Kim et al, 2008;Liu et al, 2023;Zhang et al, 2022). Therefore, we investigated whether the protein possesses both S5H and FNS activities.…”