Small RNAs mediate transgenerational inheritance of genome-wide trans-acting epialleles in maize

• DOI: 10.1186/s13059-022-02614-0
• Publication Date: 2022-02-09T12:20:02Z
• Authors: Shuai Cao; Longfei Wang; Tongwen Han; Wenxue Ye; Yang Liu; Yi Sun; Stephen P. Moose; Qingxin Song; Z. Jeffrey Chen
• Keywords: Introgression; Non-Mendelian inheritance; Genomic Imprinting

Abstract Background Hybridization and backcrossing are commonly used in animal plant breeding to induce heritable variation including epigenetic changes such as paramutation. However, the molecular basis for hybrid-induced memory remains elusive. Results Here, we report that hybridization between inbred parents B73 Mo17 induces trans -acting hypermethylation hypomethylation at thousands of loci; several hundreds (~ 3%) transmitted through six three selfing generations. Notably, many transgenerational methylation patterns resemble epialleles nonrecurrent parent, despite > 99% overall genomic loci converted recurrent parent. These depend on 24-nt siRNAs, which eliminated isogenic hybrid Mo17xB73: mop1-1 is defective siRNA biogenesis. This phenomenon resembles paramutation-like events occurs both intraspecific (Mo17xB73) interspecific (W22xTeosinte) maize populations. Moreover, abundance levels these can affect expression their associated epigenes, related stress responses. Conclusion Divergent siRNAs hybridizing hybrids, while induced status maintained inheritance during backcross breeding, alters epigene enhance growth adaptation. genetic principles may apply broadly from plants animals.