Potential of Genome Editing to Capture Diversity From Australian Wild Rice Relatives

Abstract

Rice, a staple food worldwide and a model crop, could benefit from the introduction of novel genetics from wild relatives. Wild rice in the AA genome group closely related to domesticated rice is found across the tropical world. Due to their locality outside the range of domesticated rice, Australian wild rice populations are a potential source of unique traits for rice breeding. These rice species provide a diverse gene pool for improvement that could be utilized for desirable traits such as stress resistance, disease tolerance, and nutritional qualities. However, they remain poorly characterized. The CRISPR/Cas system has revolutionized gene editing and has improved our understanding of gene functions. Coupled with the increasing availability of genomic information on the species, genes in Australian wild rice could be modified through genome editing technologies to produce new domesticates. Alternatively, beneficial alleles from these rice species could be incorporated into cultivated rice to improve critical traits. Here, we summarize the beneficial traits in Australian wild rice, the available genomic information and the potential of gene editing to discover and understand the functions of novel alleles. Moreover, we discuss the potential domestication of these wild rice species for health and economic benefits to rice production globally.

Genomic characterization supporting the development of new food and crop options from the Australian flora

“…Knowledge of the genomes of other species with potential for domestication (e.g. the rice, sorghum, millet and pulse relatives) will greatly accelerate the process in the near future by allowing molecular analysis to guide domestication using rapid methods such as gene editing 25 . Genomics will also enable novel gene discovery that can contribute genes to crops to improve performance, environmental adaptation or nutritional or functional traits 96,99 .…”

“…the rice, Sorghum, millet and pulse relatives) will greatly accelerate the process in the near future by allowing molecular analysis to guide domestication using rapid methods such as gene editing. 25 Genomics will also enable novel gene discovery that can contribute genes to crops to improve performance, environmental adaptation or nutritional or functional traits. 96,99 Many Australian species also have wide utility beyond food crops as ornamentals, pasture, bre, and timber species that will be more accessible with genomic tools.…”

“…The availability of new high quality genome sequence also makes efforts to rapidly domesticate a plant using gene editing a more viable option. For example, grasses could be domesticated as new cereals by targeting the genes that were selected in domestication of the small number of current cereal crop species 25 . Selection of grasses from novel environments offers the potential to generate cereals adapted to novel or altered environments.…”

“…The genome is estimated to be 370 Mb with around 46% of the genome being Gypsy rich repetitive elements 36 . Knowledge of this genome is being used to guide editing to produce a new domesticated crop 25 with the desirable disease resistance and quality characteristics of this species. This species has large grains suggesting the possibility that a long period of human use by wild harvest may have impacted upon the genetics of these populations 29,42 .…”

“…For example, grasses could be domesticated as new cereals by targeting the genes that were selected in domestication of the small number of current cereal crop species. 25 Selection of grasses from novel environments offers the potential to generate cereals adapted to novel or altered environments.…”