Dynamic N6 -methyladenosine RNA modification regulates peanut resistance to bacterial wilt

N6 -methyladenosine (m6 A) is the most abundant mRNA modification in eukaryotes and is an important regulator of gene expression as well as many other critical biological processes. However, the characteristics and functions of m6 A in peanut (Arachis hypogea L.) resistance to bacterial wilt (BW) remain unknown. Here, we analyzed the dynamic of m6 A during infection of resistant (H108) and susceptible (H107) peanut accessions with Ralstonia solanacearum (R. solanacearum), the causative agent of BW. Throughout the transcriptome, we identified 'URUAY' as a highly conserved motif for m6 A in peanut. The majority of differential m6 A located within the 3' untranslated region (UTR) of the transcript, with fewer in the exons. Integrative analysis of RNA-Seq and m6 A methylomes suggests the correlation between m6 A and gene expression in peanut R. solanacearum infection, and functional analysis reveals that m6 A-associated genes were related to plant-pathogen interaction. Our experimental analysis suggests that AhALKBH15 is an m6 A demethylase in peanut, leading to decreased m6 A levels and upregulation of the resistance gene AhCQ2G6Y. The upregulation of AhCQ2G6Y expression appears to promote BW resistance in the H108 accession.

Genome-wide identification and analysis of long noncoding RNAs (lncRNAs) during seed development in peanut (Arachis hypogaea L.)

BACKGROUND

Long noncoding RNAs (lncRNAs) have several known functions involving various biological regulatory processes in plant. However, the possible roles of lncRNAs during peanut seed development have not been fully explored.

RESULTS

In this study, two peanut recombinant inbred lines (RIL₈) that differ in seed size were used to investigate comprehensive lncRNA profiles derived from the seed development at 15 and 35 days after flowering (DAF). We identified a total of 9388 known and 4037 novel lncRNAs, from which 1437 were differentially expressed lncRNAs. Interestingly, the expression patterns of a number of lncRNAs can be very different between two closely related inbred lines and these lncRNAs were expressed predominantly in only one RIL at 35 DAF. Some differentially expressed lncRNAs were found related to putative cis-acting target genes and predicted to be involved in transcription, transport, cell division, and plant hormone biosynthesis. The expression patterns of several representative lncRNAs and 12 protein-coding genes were validated by qPCR. Same expression pattern was observed between most lncRNAs and their target genes. 11 lncRNAs, XR_001593099.1, MSTRG.18462.1, MSTRG.34915.1, MSTRG.41848.1, MSTRG.22884.1, MSTRG.12404.1, MSTRG.26719.1, MSTRG.35761.1, MSTRG.20033.1, MSTRG.13500.1, and MSTRG.9304.1 and their cis-acting target genes may play key roles in peanut seed development.

CONCLUSIONS

These results provided new information on lncRNA-mediated regulatory roles in peanut seed development, contributing to the comprehensive understanding of the molecular mechanisms involved in peanut seed development.