title: Functional characterization of tomato membrane-bound NAC transcription factors.
abstract: Genome-wide analysis was carried out to identify and analyze differential expression pattern of tomato membrane bound NAC transcription factors (SlNACMTFs) during stresses. Two biotic-stress-related SlNACMTFs have been characterized to elucidate their regulatory function. NAC transcription factors are known regulators of stress-related gene expression. As Stresses are perceived and transmitted by membrane-bound proteins, functional characterization of membrane-associated NAC transcription factors in tomato can reveal valuable insight about membrane-mediated stress-signalling. Tomato genome encodes 13 NAC genes which have predicted transmembrane domain(s) (SlNACMTFs). mRNA of 12 SlNACMTFs were readily detected in multiple tissues, and also in polysome isolated from leaf, confirming active transcription and translation from these genes occur under normal physiological condition. Additionally, most of the SlNACMTFs were differentially regulated during stresses and stress-related transcription factor binding sites are prevalent in their promoters. SlNACMTF3 and 8 were majorly regulated in biotic and abiotic stresses. Like other MTFs, SlNACMTF3 was translocated to the plasma membrane, whereas the C-terminus truncated (ΔC) form localized in the cytoplasm and the nucleus. Accordingly, the ΔC forms significantly influenced the activity of promoters harbouring NAC binding sites (NACbs). Furthermore, the NAC domain of these transcription factors could directly interact with an NACbs, and the proteins failed to regulate a promoter lacking a crucial NACbs. Interestingly, the type of influence to an NACbs containing promoter was dependent on the context of the NACbs, as the same SlNACMTF showed an alternative mode of regulation on different promoters, as well as the same promoter activity was oppositely regulated by two different SlNACMTF. Finally, both SlNACMTFs demonstrated the differential regulatory effect on the expression of several stress-related genes by interacting with the putative NACbs in their promoter region, suggesting their direct role in plant stress response.
authors.affiliation: Division of Plant Biology, Bose Institute, P1/12 CIT Scheme VII (M), Kolkata, 700054, India.
authors.forename: Payel
authors.initials: P
authors.lastname: Bhattacharjee
authors.affiliation: Division of Plant Biology, Bose Institute, P1/12 CIT Scheme VII (M), Kolkata, 700054, India.
authors.forename: Rohit
authors.initials: R
authors.lastname: Das
authors.affiliation: Division of Plant Biology, Bose Institute, P1/12 CIT Scheme VII (M), Kolkata, 700054, India.
authors.forename: Arunava
authors.initials: A
authors.lastname: Mandal
authors.affiliation: Division of Plant Biology, Bose Institute, P1/12 CIT Scheme VII (M), Kolkata, 700054, India. pkundu@jcbose.ac.in.
authors.forename: Pallob
authors.initials: P
authors.lastname: Kundu
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000528:Alternaria / Q000502:physiology; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018551:Solanum lycopersicum / Q000235:genetics* / Q000382:microbiology; D008565:Membrane Proteins / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature; D014157:Transcription Factors / Q000145:classification / Q000235:genetics*
chemical_list: D008565:Membrane Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D012965:Sodium Chloride
keywords: Alternaria solani; Membrane localisation; NAC; NACMTF; NACbs; ToLCNDV; Transcription factor