Intra species dissection of phytophthora capsici resistance in black pepper.

INTRODUCTION

Black pepper, a financially significant tropical crop, assumes a pivotal role in global agriculture for the major source of specie flavor. Nonetheless, the growth and productivity of black pepper face severe impediments due to the destructive pathogen Phytophthora capsici, ultimately resulting in black pepper blight. The dissecting for the genetic source of pathogen resistance for black pepper is beneficial for its global production. The genetic sources include the variations on gene coding sequences, transcription capabilities and epigenetic modifications, which exerts hierarchy of influences on plant defense against pathogen. However, the understanding of genetic source of disease resistance in black pepper remains limited.

METHODS

The wild species Piper flaviflorum (P. flaviflorum, Pf) is known for blight resistance, while the cultivated species P. nigrum is susceptible. To dissecting the genetic sources of pathogen resistance for black pepper, the chromatin modification on H3K4me3 and transcriptome of black pepper species were profiled for genome wide comparative studies, applied with CUT&Tag and RNA sequencing technologies.

RESULTS

The intraspecies difference between P. flaviflorum and P. nigrum on gene body region led to coding variations on 5137 genes, including 359 gene with biotic stress responses and regulation. P. flaviflorum exhibited a more comprehensive resistance response to Phytophthora capsici in terms of transcriptome features. The pathogen responsive transcribing was significant associated with histone modification mark of H3K4me3 in black pepper. The collective data on variations of sequence, transcription activity and chromatin structure lead to an exclusive jasmonic acid-responsive pathway for disease resistance in P. flaviflorum was revealed. This research provides a comprehensive frame work to identify the fine genetic source for pathogen resistance from wild species of black pepper.