Abstract:Sorghum is the fifth most important cereal crops in the world and shows strong tolerance to low-fertility soil and drought. Nitrogen is one of the three essential nutrients which ensures stable and high crop yield. The nitrogen signaling pathways in sorghum remains largely unknown. Deciphering the nitrogen deficiency inducible genes will help to analyze the molecular pathways involved in sorghum nitrogen absorption and utilization. A member of MYB-related transcription factor family， SbMYB-like （Sb03g030330） was cloned based on the global gene expression profiles of sorghum seedlings under nitrogen， phosphorus， and potassium deficiency conditions. SbMYB-like was found being inducible by nitrogen deficiency in shoots， and its deduced protein SbMYB-like was predicted to be localized in the nucleus. qRT-PCR analysis showed that the transcripts of SbMYB-like were lower in roots， stems and flowers， whereas abundant in leaves. Phylogenetic tree analysis indicated that SbMYB-like was closely grouped with its homologs in maize and Brachypodium P. Beauv.， and both homologs were inducible under nitrogen deficiency condition by qRT-PCR. The SbMYB-like coding sequence from sorghum BTX623 variety was isolated and transformed into Arabidopsis Heynh. driven by a constitutive promoter. The growth parameters of SbMYB-like over-expressing plants under nitrogen and phosphorus deficiency conditions were measured. The results showed that SbMYB-like was involved in root elongation and flowering independent of the environmental nitrogen levels. Collectively， this study provided basic data for analysis molecular mechanism of sorghum response to nitrogen deficiency.