Identification of the targets of HbEIN3/EILs in genomic wide in Hevea brasiliensis.

ABSTRACT

EIN3/EILs are key regulators in ET signaling pathway. In this work, 4 members of EIN3/EILs of Hevea brasiliensis (HbEIN3/EILs) showed interaction with two F box proteins, HbEBF1 and HbEBF2. HbEIN3 located in nucleus and exhibited strong transcriptional activity. HbEIN3 was induced by ET treatment in C-serum, but not in B-serum of latex. HbEIN3/EILs bound to G-box cis-element. To globally search the potential targets of HbEIN3/EILs, genomic sequences of H. brasiliensis was re-annotated and an HCES (Hevea Cis-Elements Scanning) program was developed ( www.h-brasiliensis.com ). HCES scanning results showed that ET- and JA- responsive cis-elements distribute overlapping in gene promoters. 3146 genes containing G-box in promoters are potential targets of HbEIN3, including 41 genes involved in biosynthesis and drainage of latex, of which 7 rate-limiting genes of latex production were regulated by both ET and JA, suggesting that ET and JA signaling pathways coordinated the latex biosynthesis and drainage in H. brasiliensis. Abbreviations ABRE ABA responsive elements; bHLH basic helix-loop-helix; COG Orthologous Groups; DRE dehydration response element; ERE ethylene responsive element; ET Ethylene; GO Gene Ontology; HCES Hevea Cis-Elements Scanning; JA jasmonates; JRE Jasmonate-responsive element; KEGG Kyoto Encyclopedia of Genes and Genomes; NR non-redundant database; PLACE Plant Cis-acting Regulatory DNA Elements; qRT-PCR quantitative real-time RT-PCR.