Loss of susceptibility as a novel breeding strategy for durable and broad-spectrum resistance

Abstract

Recent studies on plant immunity have suggested that a pathogen should suppress induced plant defense in order to infect a plant species, which otherwise would have been a nonhost to the pathogen. For this purpose, pathogens exploit effector molecules to interfere with different layers of plant defense responses. In this review, we summarize the latest findings on plant factors that are activated by pathogen effectors to suppress plant immunity. By looking from a different point of view into host and nonhost resistance, we propose a novel breeding strategy: disabling plant disease susceptibility genes (S-genes) to achieve durable and broad-spectrum resistance.

Optimization of EMS Mutagenesis on Petunia for TILLING

“…A mutagenized population was produced that is suitable for screening by genetic techniques such as TILLING [19][20][21].…”

Genetics and molecular mechanisms of resistance to powdery mildews in tomato (Solanum lycopersicum) and its wild relatives

“…In addition to the mlo and pmr mutants, a considerable number of S-genes have been identified in Arabidopsis (reviewed by Pavan et al 2010); e.g., downy mildew resistance (dmr1 to 6) mutants (Van Damme et al 2005). Based on studies on effectortriggerred susceptibility and by looking from a different point of view into host and non-host resistance (Fig.…”

“…Based on studies on effectortriggerred susceptibility and by looking from a different point of view into host and non-host resistance (Fig. 5), we proposed in 2010 a novel breeding strategy: disabling plant S-genes to achieve non-host-like resistance (Pavan et al 2010). We are currently verifying whether silencing tomato orthologs of these Arabidopsis S-genes leads to resistance to O. neolycopersici.…”

Genome-wide Identification, Classification and Expression Analysis of the Mildew Resistance Locus O ( MLO ) Gene Family in Sweet Orange ( Citrus sinensis )

“…Particular homologs of the MLO family serve as perceptivity roles towards the PM fungi. Furthermore, their deactivation, through silencing or loss-of-function mutations, has been associated with a specific form of PM resistance, interpreted as mlo resistance [ 6 ]. This is connected with the increasement of exocytosis defense pathways at plant-pathogen interaction sites, which are perceived to result in the prevention of fungal penetration into host plants [ 7 ].…”

“…Originally discovered in Hordeum vulgare (barley), mlo immunity has also been found to exist in several plant species later, particularly Arabidopsis . This consequently led to the breeding protocol founded upon the methodical inactivation of MLO susceptibility genes across planted varieties infected by the PM fungi [ 6,9,14 ]. Proof of formalization of this approach has been recently conducted by the experiment, showing the introduction of PM resistance in Triticum aestivum (bread wheat) following targeted mutagenesis of 3 MLO homoeoalleles by the CRISPR-Cas9 and TALEN system [ 13 ].…”