Genome-Wide Identification and Expression Analysis of Growth-Regulating Factor Family in Sweet Potato and Its Two Relatives

Growth-regulating factor (GRF) is a multi-gene family that plays an important role in plant growth and development and is widely present in plants. Currently, <i>GRF</i> gene members have been reported in many plants, but the <i>GRF</i> gene family has not been found in sweet potato. In this study, ten <i>GRF</i> genes were identified in sweet potato (<i>Ipomoea batatas</i>), twelve and twelve were identified in its two diploid relatives (<i>Ipomoea trifida</i>) and (<i>Ipomoea triloba</i>), which were unevenly distributed on nine different chromosomes. Subcellular localization analysis showed that <i>GRF</i> genes of sweet potato, <i>I. trifida</i>, and <i>I. triloba</i> were all located in the nucleus. The expression analysis showed that the expression of <i>IbGRFs</i> was diverse in different sweet potato parts, and most of the genes were upregulated and even had the highest expression in the vigorous growth buds. These findings provide molecular characterization of sweet potato and its two diploid relatives, the <i>GRF</i> families, further supporting functional characterization.