A pigeonpea gene confers resistance to Asian soybean rust in soybean

Abstract

Asian soybean rust (ASR), caused by the fungus Phakopsora pachyrhizi, is one of the most economically important crop diseases, but is only treatable with fungicides, which are becoming less effective owing to the emergence of fungicide resistance. There are no commercial soybean cultivars with durable resistance to P. pachyrhizi, and although soybean resistance loci have been mapped, no resistance genes have been cloned. We report the cloning of a P. pachyrhizi resistance gene CcRpp1 (Cajanus cajan Resistance against Phakopsora pachyrhizi 1) from pigeonpea (Cajanus cajan) and show that CcRpp1 confers full resistance to P. pachyrhizi in soybean. Our findings show that legume species related to soybean such as pigeonpea, cowpea, common bean and others could provide a valuable and diverse pool of resistance traits for crop improvement.

An overview of genetic rust resistance: From broad to specific mechanisms

“…Since genetic resistance can provide effective and chemical-free disease control, many efforts are directed towards isolating rust-resistance genes in crop plants and understanding how to best deploy them for durable resistance [3]. In addition, related nonhost species are increasingly being utilised to identify new sources of resistance [4, 5]. Here, we summarise current knowledge of rust resistance, focussing on race-specific, non–race-specific, and nonhost resistance mechanisms.…”

Fine Mapping and Transcriptome Analysis Reveal Candidate Genes Associated with Hybrid Lethality in Cabbage (Brassica Oleracea)

“…Kawashima et al reported that they cloned a Phakopsora pachyrhizi resistance gene, CcRpp1 , from pigeonpea ( Cajanus cajan ), and they showed that CcRpp1 conferred full resistance to P. pachyrhizi in soybean by applying map-based cloning approaches and transcriptome analysis [47]. …”

Genetic Engineering and Sustainable Crop Disease Management: Opportunities for Case-by-Case Decision-Making

“…This R gene is expected to provide an alternative to the repeated use of foliar copper applications, benefiting both field workers and the environment [54]. Other examples of "mining" of R genes from related as well as unrelated plant species have been published for both monocots and dicots [47,55,56]. Recent research has also shown that it is possible to enhance disease resistance by modifying the target of a pathogen effector so that it recognizes other pathogen effectors [57].…”