Evolution of PEPC gene family in Gossypium reveals functional diversification and GhPEPC genes responding to abiotic stresses

Abstract Phosphoenolpyruvate carboxylase(PEPC) family genesplay important roles in regulating plant growth and abiotic stressresponse. Based on the sequenced Gossypiumgenomes, we performed comprehensive analysis of PEPC homolog genesin cotton, which six, six, eleven and ten PEPC geneswere identified in Gossypiumarboreum (A 2 ), G. raimondii (D 5 ), G. hirsutum (AD 1 ) and G. barbadense (AD 2 ), respectively. These geneswere divided into six subgroups: PEPC-i, PEPC-ii, PEPC-iii, PEPC-iv, PEPC-v and PEPC-vi; PEPC genesin each subgroup displayed conserved genestructure and motifs. Segmental duplicationand whole genome duplication (WGD) events yielded the expansion of PEPC genes. Expression assays showed that the duplicated PEPC genesdisplayed diverse expression patterns, indicating that they experienced functional divergence. Of which, genesin PEPC-iv subgroup played crucial role for substrate distribution in cottonseed. Cis -elements, putative miRNAs and expression analyses showed that GhPEPC homologs might respond to abiotic stresses, expression levels of GhPEPC1 and GhPEPC2/GhPEPC2D geneswere larger induced than other GhPEPC genesunder cold, heat, salt, and drought stresses, indicating the crucial roles in abiotic stressesresponse. Present study serves new information to decipher the evolution and function of PEPC genesin Gossypium.