Abiotic stress-related Cis-elements analysis in promoters of Aeluropus littoralis NAC genes

NAC (NAM, ATAF1/2, and CUC2) proteins are the plant-specific transcription factors (TFs) that play roles in diverse developmental processes and stress responses. In the present study, a total of 68 NAC genes were identified in Aeluropus littoralis, a salt secreting halophytic grass, belongs to family Poaceae. By analysis of cis regulatory elements of AlNAC genes promoter, many cis-acting regulatory elements related to growth and development, phytohormone and stresses defense were found in the promoter of AlNAC genes. These hormone-responsive elements, include P-box, TCA element, CGTCA-motif and TGACG-motif, TGA-element, ERE and ABRE, which were associated with gibberellic acid, salicylic acid, jasmonic acid, Auxin, ethylene and abscisic acid response, respectively. For stress responsive elements, TC-rich repeats, ARE, MBS, LTR; and W box, can be noted which are related to defense and stress, anaerobic induction, drought inducibility, low-temperature inducibility, and wound stress, respectively. The different types of cis regulatory elements in the promoter of AlNAC genes and the variability in transcription factors associated with these regulatory elements indicates the important role of these genes in plant development and defense against stress. By analyzing AlNAC32 candidate gene expression using RT-qPCR it was revealed that AlNAC32 was up-regulated under salt, drought and ABA phytohormone stresses in leaf, stem and root tissues, implying its role in multiple abiotic stresses tolerance. These findings provided valuable information for further research on the functions and applications of AlNACs in A. littoralis growth and adaptation to stress.