Differential Expression of PBF Dof Transcription Factor in Different Tissues of Three Finger Millet Genotypes Differing in Seed Protein Content and Color

作者：Gupta Nidhi; Gupta Atul Kumar; Singh N K; Kumar Anil^*

来源：Plant Molecular Biology Reporter, 2011, 29(1): 69-76.

DOI：10.1007/s11105-010-0208-y

• Finger millet
• PBF Dof
• Seed storage proteins
• Reverse transcriptase PCR
• Real-time PCR

Finger millet is one of the most nutritious cereal crops, as it is rich in calcium, minerals, and phosphorus. It also contains high protein, with prolamins being the major seed storage proteins. Genes encoding prolamins are coordinately expressed in developing endosperm wherein they are under spatial and temporal transcription control, involving cis-acting and trans-acting motifs in their promoters and trans-acting transcription factors. The PBF Dof (prolamin-binding factor DNA binding with one finger only) transcription factor can be an important regulator for seed storage protein gene expression. In this study, the spatial distribution of the PBF Dof gene has been investigated in different tissues, including root, stem, and flag leaf during vegetative growth as well as S1, S2, S3, and S4 stages of developing spikes in three finger millet genotypes, including brown (PRM-1), golden (PRM-701), and white (PRM-801) differing in grain protein content and color using reverse transcriptase polymerase chain reaction (PCR) and real-time PCR. Semi- quantitative and quantitative PCR results revealed that PBF Dof is expressed in all tissues analyzed; however, expression of PBF Dof is relatively higher in developing stages of spikes than in other tissues in all three genotypes. Spatial expression of PBF Dof genes in all tissues analyzed is similar to that reported for wheat PBF genes but in contrast to that of barley and maize PBFs wherein expression is restricted to the endosperm. Moreover, a negative correlation is observed between prolamin content and each of grain yield and grain protein in all three finger millet genotypes. The grain protein content of the white (PRM-801) genotype is highest (9.56%), followed by golden (PRM-701; 9.0%) and brown (PRM-1; 7.5%) genotypes, and it is related to higher expression of PBF Dof in S2, S3, and S4 stages, respectively. This indicates that early induction of seed protein genes in the white genotype provides a longer period for accumulation of seed storage proteins in the endosperm when compared with those in other genotypes.

• 出版日期2011-3