Comparative transcriptome analysis identifies jasmonic pathway genes related to anther dehiscence in Solanum melongena L.

Abstract

Background: Anther indehiscence is an important form of functional male sterility that can facilitate the production of hybrid seeds. However, the molecular mechanisms of anther indehiscence-based male sterility in eggplant (Solanum melongena L.) have not been thoroughly explored. Therefore, we performed RNA-seq analysis to investigate the molecular mechanisms of anther dehiscence in eggplant. Results: We used transcriptome sequencing and qRT-PCR assays to compare the anthers of normally developing (F142) and anther indehiscent (S12) eggplant. We identified 2670 differentially expressed genes between lines. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 31 differentially expressed genes related to hormone biosynthesis. We therefore measured the contents of the phytohormones jasmonic acid (JA), IAA, GA3 and ABA in S12 and F142. There were no significant differences in IAA, GA3 or ABA levels between S12 and F142. However, JA levels were significantly lower in S12 than in F142. Five key genes in the JA signaling pathway were differentially expressed in S12 vs. F142. Of these, SmJAZ and SmJAR-like were significantly up-regulated and SmDAD1, SmLOX and SmCOI1 were down-regulated in S12 vs. F142. In DNA-protein interaction studies, SmLOX, SmAOC, SmOPR3, SmCOI1 and SmJAZ1 failed to be enriched on the chromatin of SmDAD1. Protein–protein interaction studies identified a direct interaction between SmDAD1 and SmLOX, but SmDAD1 failed to interact with SmAOC, SmOPR3, SmCOI1 and SmJAZ1. Conclusion: JA is an essential factor affecting anther dehiscence in eggplant. SmDAD1 interacts with SmLOX to alter JA levels, thereby regulating anther dehiscence. Our data represent a valuable resource for further exploring the regulatory mechanisms underlying anther dehiscence in eggplant.