Overexpression of Lectin Receptor-Like Kinase 1 in Tomato Confers Resistance to Fusarium oxysporum f. sp. Radicis-Lycopersici.

Zhi-Liang Yue,Sheng-Wei Zhang,Zhe-Juan Tian,Jun-Wei Zhang,Ya-Dong Li,Zhi-Ming Wu

doi:10.3389/fpls.2022.836269

Abstract

The disease Fusarium crown and root rot (FCRR), caused mainly by Fusarium oxysporum f. sp. radicis-lycopersici (FORL), seriously affects commercial tomato [Solanum lycopersicum (Sl)] yields. However, the genes that offer resistance to FORL are limited and the mechanism of resistance to FCRR is poorly understood. Lectin receptor-like kinases (LecRKs) play critical roles in defensive responses and immunity in many plant species; however, whether specific LecRKs are involved in the response of tomato plants to FORL is unclear. Here, we report that the expression of SlLecRK1/Solyc09g011070.1 was obviously induced by the infection of FORL. Biochemical and cell biological data revealed that SlLecRK1 is an active kinase that is located at the cell membrane, while real-time quantitative PCR data suggested that SlLecRK1 is mainly expressed in stems and roots. Genetic studies showed that overexpression of SlLecRK1 significantly improved the resistance of tomato plants to FORL but did not cause visible changes in plant growth and development compared with wild-type control plants. RNA-Seq data suggested that the positive effects of SlLecRK1 on the resistance of tomato plants to FORL occur mainly by triggering the expression of ethylene-responsive transcription factor (ERF) genes. Together, our findings not only identify a new target for the development of FCRR-resistant tomato varieties, they also demonstrate a molecular mechanism linking SlLecRK1 and ERFs in regulating the immune responses of tomato plants to FORL.

Highlights

Decades of research have revealed that crop succession can lead to soil-borne diseases such as Fusarium crown and root rot (FCRR), an emerging disease that seriously threatens tomato (Solanum lycopersicum L.) production in most countries (Polizzi et al, 2011; Cordero-Ramirez et al, 2013; Sepulveda-Chavera et al, 2014)
There are more than 100 genes encoding lectin RLKs (LecRKs),6 and 10 of them show relatively higher identity (42–47%) to LecRK-I.9/DORN1
Total RNA was extracted from 10-day-old WT tomato seedlings that had been treated with FORL 1 day earlier

Summary

Introduction

Decades of research have revealed that crop succession can lead to soil-borne diseases such as Fusarium crown and root rot (FCRR), an emerging disease that seriously threatens tomato (Solanum lycopersicum L.) production in most countries (Polizzi et al, 2011; Cordero-Ramirez et al, 2013; Sepulveda-Chavera et al, 2014). The application of disinfectants and fungicides is a major approach to reduce FCRR; such chemical control is extensively used in the commercial production of tomatoes (Benhamou and Belanger, 1998; Myresiotis et al, 2012). Biological resources, including bacteria and fungi, have been used to control FCRR in tomato (Chin et al, 2000; Grauwet et al, 2005; Kavroulakis et al, 2007; Nefzi et al, 2019). These methods are of limited usefulness during a disease outbreak. Though the development of resistant tomato varieties would be an efficient and economical approach to the control of FCRR in tomato, our understanding of the genes conferring resistance to FORL is limited and the mechanisms of resistance are poorly understood (Mazzeo et al, 2014; Manzo et al, 2016)

Methods

Results

Conclusion