| Summary: | Auxin response factors (ARFs) are a transcription factor family that regulates the expression of auxin phase-responsive genes. Here, we performed a genome-wide investigation of the tetraploid blueberry (<i>Vaccinium corymbosum</i> cv. ‘Draper’) genome sequence. Physical and chemical properties, phylogenetic evolution, gene structure, conservative motifs, chromosome location, and cis-acting elements of blueberry <i>ARF</i> genes were comprehensively evaluated. A total of 70 blueberry <i>ARF</i> genes (<i>VcARF</i>) were found in its genome, which could be divided into six subfamilies. <i>VcARF</i> genes were unevenly distributed on 40 chromosomes and were observed to encode protein sequences ranging in length from 162 to 1117 amino acids. Their exon numbers range from 2 to 22. <i>VcARF</i> promoter regions contain multiple functional domains associated with light signaling, aerobic metabolism, plant hormones, stress, and cell cycle regulation. More family members of <i>VcARF</i> genes were discovered in blueberry than in previously studied plants, likely because of the occurrence of whole-genome duplication and/or tandem duplication. <i>VcARF</i> expression patterns were analyzed at different stages of fruit development, and <i>VcARF3</i>, <i>VcARF4</i>, <i>VcARF14</i>, <i>VcARF37</i>, and <i>VcARF52</i> were observed to play important roles. <i>VcARF3</i> and <i>VcARF4</i> appeared to function as repressors, while <i>VcARF14</i> acted as an essential factor in fruit firmness differences between firm and soft flesh cultivars.
|
|---|