Molecular Cloning, In Silico Characterization, and Promoter Analysis of a Putative ETHE1 Gene from Jatropha curcas.

Sulfur metabolism and stress responses are fundamental to plant growth and seed development. ETHE1 encodes a mitochondrial sulfur dioxygenase that plays important roles in these processes; however, its function in Jatropha curcas remains unknown. In this study, we report the cloning and in silico characterization of a putative JcETHE1 gene from J. curcas. Bioinformatic analysis revealed that JcETHE1 has an open reading frame of 726 bp encoding a 241-amino-acid protein, which is predicted to localize in mitochondria and possesses a typical sulfur dioxygenase conserved domain. Because the transcript ends were not experimentally confirmed and the predicted protein is shorter than related plant homologues, the possibility that the cloned sequence is partial cannot be excluded. Phylogenetic analysis showed that JcETHE1 clusters within the Euphorbiaceae clade, showing high similarity to ETHE1 from Manihot esculenta and Hevea brasiliensis. In silico promoter analysis suggested that, in addition to core elements, the JcETHE1 promoter contains multiple putative regulatory elements associated with light response, hormone responses (ABA, ethylene, gibberellin), floral development (CArG-box, AAGAA-motif), stress responses, and endosperm development. These findings provide a molecular basis for future functional studies of JcETHE1 and suggest that it may serve as a potential candidate gene for further investigation into reproductive development and stress responses in J. curcas. However, these hypotheses require experimental validation.