Comparative analysis of Constitutive and fiber-specific promoters under the expression pattern of Expansin gene in transgenic Cotton

• Published in: PloS one Vol. 15; no. 3; p. e0230519
• Main Authors: Yaqoob, Amina, Ali Shahid, Ahmad, Salisu, Ibrahim Bala, Shakoor, Sana, Usmaan, Muhammad, Shad, Mohsin, Rao, Abdul Qayyum
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18-03-2020; Public Library of Science (PLoS)
• Subjects: Biology and Life Sciences; Cassettes; Cauliflowers; Cellulose; Cellulose fibers; Comparative analysis; Cotton; Cotton (Fiber); Cotton fibers; Deoxyribonucleic acid; DNA; Engineering and Technology; Excellence; Fineness; Fluorescence; Gene expression; Genes; Genetic aspects; Genetic engineering; Genetic research; Genetic transformation; Genetically modified crops; Gossypium hirsutum; Molecular biology; Nature; Physical Sciences; Plant fiber industry; Plant genetics; Plant growth; Polysaccharides; Promoters; Proteins; Research and Analysis Methods; Seed coats; Seeds; Transcription (Genetics); Transcription initiation; Transgenic plants; Viruses; Pakistan; Lahore Pakistan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0230519

Promoters are specified segments of DNA that lead to the initiation of transcription of a specific gene. The designing of a gene cassette for plant transformation is significantly dependent upon the specificity of a promoter. Constitutive Cauliflower mosaic virus promoter, CaMV35S, due to its developmental role, is the most commonly used promoter in plant transformation. While Gossypium hirsutum (Gh) being fiber-specific promoter (GhSCFP) specifically activates transcription in seed coat and fiber associated genes. The Expansin genes are renowned for their versatile roles in plant growth. The overexpression of Expansin genes has been reported to enhance fiber length and fineness. Thus, in this study, a local Cotton variety was transformed with Expansin (CpEXPA1) gene, in the form of two separate cassettes, each with a different promoter, named as 35SEXPA1 and FSEXPA1 expressed under CaMV35S and GhSCFP promoters respectively. Integration and Spatiotemporal relative expression of the transgene were studied in an advanced generation. GhSCFP bearing transgene expression was significantly higher in Cotton fiber than other plant parts. While transgene with CaMV35S promoter was found to be continually expressing in all tissues but the expression was lower in fiber than that expressed under GhSCFP. The temporal expression profile was quite interesting with a gradual increasing pattern of both constructs from 1DPA (days post anthesis) to 18DPA and decreased expression from 24 to 30 DPA. Besides the relative expression of promoters, fiber cellulose quantification and fluorescence intensity were also observed. The study significantly compared the two most commonly used promoters and it is deduced from the results that the GhSCFP promoter could be used more efficiently in fiber when compared with CaMV35S which being constitutive in nature preferred for expression in all parts of the plant.