Impairment of Tomato WAT1 Enhances Resistance to Vascular Wilt Fungi Despite Severe Growth Defects

Abstract

Verticillium dahliae is a particularly notorious vascular wilt pathogen of tomato and poses a reoccurring challenge to crop protection as limited qualitative resistance is available. Therefore, alternative approaches for crop protection are pursued. One such strategy is the impairment of disease susceptibility (S) genes, which are plant genes targeted by pathogens to promote disease development. In Arabidopsis and cotton, the Walls Are Thin 1 (WAT1) gene has shown to be a S gene for V. dahliae. In this study, we identified the tomato WAT1 homolog Solyc04g080940 (SlWAT1). Transient and stable silencing of SlWAT1, based on virus-induced gene silencing (VIGS) and RNAi, respectively, did not consistently lead to reduced V. dahliae susceptibility in tomato. However, CRISPR-Cas9 tomato mutant lines carrying targeted deletions in SlWAT1 showed significantly enhanced resistance to V. dahliae, and furthermore also to Verticillium albo-atrum and Fusarium oxysporum f. sp. lycopersici (Fol). Thus, disabling the tomato WAT1 gene resulted in broad-spectrum resistance to various vascular pathogens in tomato. Unfortunately these tomato CRISPR mutant lines suffered from severe growth defects. In order to overcome the pleiotropic effect caused by the impairment of the tomato WAT1 gene, future efforts should be devoted to identifying tomato SlWAT1 mutant alleles that do not negatively impact tomato growth and development.

Comparative analysis of Cucurbita pepo genomes shed light in agronomic traits variation

“…The pectate lyase Cp4.1LG10g04500 with variants in 968Rb in turn can affect plant cell wall thickening and PM resistance [75] as reported in Arabidopsis [76,77]. Finally, our data outlined two WAT1-related proteins (Cp4.1LG10g03270 and Cp4.1LG10g03390), affected by variants that can provide broad spectrum resistance [78,79].…”

Antifungal effects of volatile organic compounds produced by Trichoderma koningiopsis T2 against Verticillium dahliae

“…Due to the stable dormant structure microsclerotia, long-term variability, and coevolution with host plants ( Ju et al, 2020 ; Höfer et al, 2021 ; Starke et al, 2021 ), controlling the spread of Verticillium wilt in plants remains challenging using currently available methods, such as chemical control, genetic breeding, and optimization of the cropping pattern ( Ostos et al, 2020 ; Ramirez-Gil and Morales-Osorio, 2021 ; Zhang Y. L. et al, 2021 ). Disease resistance breeding is limited by a long breeding cycle and a lack of natural resistance resources, and chemical control has no beneficial effect on the control of soil-borne diseases ( Diaz-Rueda et al, 2021 ; Hanika et al, 2021 ; Sunico et al, 2022 ). With the social pressure to make agriculture more sustainable while maintaining a healthy environment, the identification of new strategies that can reduce the use of chemicals is necessary.…”

Transcriptome analyses of leaf architecture in Sansevieria support a common genetic toolkit in the parallel evolution of unifacial leaves in monocots

“…We speculate that similar cell wall to cell wall communication may be at play at the juncture of adaxial and abaxial cells at the leaf margin. Additional genes that are involved in cell wall structure include COMT1 (affects lignin deposition‐upregulated) (Ma, 2009 ; Stahl et al, 2009 ), WAT1 (responds to auxin levels, fungal pathogen resistance‐down regulated) (Denancé et al, 2010 ; Hanika et al, 2021 ; Molina et al, 2021 ; Ranocha et al, 2013 ), E13B (glucan endo‐1,3‐beta‐D‐glucosidase‐downregulated) (Hrmova & Fincher, 2001 ), and OCT3 (interacts with ethylene response factors to downregulate cell wall modifications‐upregulated) (Küfner & Koch, 2008 ). Thus, cell wall modification, pathogen resistance, and hormone response, all of which are represented in the DEGs, may all be responding to identical regulatory signals.…”