The Arabidopsis EXORDIUM-LIKE1 (EXL1) gene (At1g35140) is required for adaptation to carbon (C)- and energy-limiting growth conditions. An exl1 loss of function mutant showed diminished biomass production in a low total irradiance growth regime, impaired survival during extended night, and impaired survival of anoxia stress. We show here additional expression data and discuss the putative roles of EXL1. We hypothesize that EXL1 suppresses brassinosteroid-dependent growth and controls C allocation in the cell. In-depth expression analysis of homologous genes suggests that the EXL2 (At5g64260) and EXL4 (At5g09440) genes play similar roles.