A Sweetpotato Auxin Response Factor Gene () Is Involved in Carotenoid Biosynthesis and Salt and Drought Tolerance in Transgenic .

Auxin response factors (ARFs) compose a family of transcription factors and have been found to play major roles in the process of plant growth and development. However, their roles in plant carotenoid biosynthesis and responses to abiotic stresses are rarely known to date. In the present study, we found that the gene from sweetpotato ( (L.) Lam.) line HVB-3 increased the contents of carotenoids and enhanced the tolerance to salt and drought in transgenic . The transgenic plants exhibited the increased abscisic acid (ABA) and proline contents and superoxide dismutase (SOD) activity and the decreased HO content. Furthermore, it was found that positively regulated the genes associated with carotenoid and ABA biosynthesis and abiotic stress responses. These results suggest that is involved in carotenoid biosynthesis and salt and drought tolerance in transgenic . This study provides a novel gene for improving carotenoid contents and salt and drought tolerance of sweetpotato and other plants.