Abstract:Plant Rboh gene family encodes NADPH oxidases. The information and expression characteristics related to SaRboh genes in sandalwood (Santalum album Linn.) will contribute to study the roles of Rboh in sandalwood growth and development. Based on the fulllength transcriptome data, the cDNA sequence of SaRbohA (respiratory burst oxidase homolog) gene was obtained from roots of sandalwood. The full length of SaRbohA is 2 790 bp, encoding 929 amino acids with molecular weight 105.37 kD and isoelectric point 9.13. Subcellular localization analysis showed that SaRbohA localized on the cell membrane. Sequence alignment indicated SaRbohA has six transmembrane domains; The protein includes a typical NADPH binding domain and a FAD binding domain in Cterminal, and two EF hand structures in Nterminal. Phylogenetic tree analysis showed that the amino acid sequence similarity between SaRbohA and MdRboh of apple was the highest, reaching 63.65%. Tissuespecific expression analysis showed that the SaRbohA gene was low expression in stems, high expression in young leaves and apical buds, especially in roots of sandalwood. 2, 6dimethoxyρbenzoquinoe (an important haustoriuminducing factor) can strongly induce the expression of SaRbohA. SaRbohA may play important roles in the development of ROSmediated haustorium development and be induced by the chemical factor.