Harnessing genetic resistance to rusts in wheat and integrated rust management methods to develop more durable resistant cultivars

Abstract

Wheat is one of the most important staple foods on earth. Leaf rust, stem rust and stripe rust, caused by Puccini triticina, Puccinia f. sp. graminis and Puccinia f. sp. striiformis, respectively, continue to threaten wheat production worldwide. Utilization of resistant cultivars is the most effective and chemical-free strategy to control rust diseases. Convectional and molecular biology techniques identified more than 200 resistance genes and their associated markers from common wheat and wheat wild relatives, which can be used by breeders in resistance breeding programmes. However, there is continuous emergence of new races of rust pathogens with novel degrees of virulence, thus rendering wheat resistance genes ineffective. An integration of genomic selection, genome editing, molecular breeding and marker-assisted selection, and phenotypic evaluations is required in developing high quality wheat varieties with resistance to multiple pathogens. Although host genotype resistance and application of fungicides are the most generally utilized approaches for controlling wheat rusts, effective agronomic methods are required to reduce disease management costs and increase wheat production sustainability. This review gives a critical overview of the current knowledge of rust resistance, particularly race-specific and non-race specific resistance, the role of pathogenesis-related proteins, non-coding RNAs, and transcription factors in rust resistance, and the molecular basis of interactions between wheat and rust pathogens. It will also discuss the new advances on how integrated rust management methods can assist in developing more durable resistant cultivars in these pathosystems.

Registration of the “Woodies” multi–rust‐resistant barley germplasm

“…Despite the presence of additional resistance genes in the Woodies, the overall rust phenotype could still be influenced by extreme temperatures. Subsequent reports have linked the timing of extreme temperature events and plant maturation date with the breakdown of resistance, corroborating reports of planting date as suitable management strategy (Mapuranga et al., 2022).…”

“…These include Njoro, Kenya, between 2021 andDebre Zeit, Ethiopia, between 2021 andSt. Paul, MN, in 2018, and 2022andPullman, WA, between 2021 and. Percent severity of stem rust was collected in all locations using a modified Cobb scale (Peterson et al, 1948).…”

Fungal Secondary Metabolites and Small RNAs Enhance Pathogenicity during Plant-Fungal Pathogen Interactions

“…Plant immune responses are tightly regulated by an array of immunity-associated regulators such as sRNAs and some transcription factors [ 82 ]. Based on their biogenesis and structural features, sRNAs can be classified into three categories: short-interfering RNAs (siRNAs), dicer-independent microRNAs (miRNAs) and dicer-independent piwi interacting RNAs (piRNAs) [ 10 , 83 , 84 , 85 ].…”

“…Based on their biogenesis and structural features, sRNAs can be classified into three categories: short-interfering RNAs (siRNAs), dicer-independent microRNAs (miRNAs) and dicer-independent piwi interacting RNAs (piRNAs) [ 10 , 83 , 84 , 85 ]. The fundamental sRNA pathway components and other various sRNAs function as critical gene expression regulators to fine-tune the immunity of some cereal plants such as wheat and rice against pathogen invasion [ 82 ]. Normally, when a pathogen attacks its host, these sRNAs are either upregulated or downregulated in order to inhibit expression or to release suppression of their targets [ 6 , 86 ].…”

Mapping of prehaustorial resistance against wheat leaf rust in einkorn (Triticum monococcum), a progenitor of wheat

“…Moreover, race-specific resistance is vulnerable to breakdown by virulent races, which occurs after a mutation of an elicitor or the interacting resistance gene in the host. More than 100 leaf rust resistance genes ( Lr- genes) have been described; however, only a few are carried by cultivars due to linkage drag and undesired agronomic properties ( Mapuranga et al., 2022 ). The lifespan of such vertical/qualitative resistance carried by cultivars was calculated by Mapuranga et al.…”