Expression Characteristics and Functional Analysis of the ScWRKY3 Gene from Sugarcane.

The plant-specific WRKY transcriptional regulatory factors have been proven to play vital roles in plant growth, development, and responses to biotic and abiotic stresses. However, there are few studies on the gene family in sugarcane ( spp.). In the present study, the characterization of a new subgroup, IIc WRKY protein ScWRKY3, from a hybrid cultivar is reported. The ScWRKY3 protein was localized in the nucleus of leaves and showed no transcriptional activation activity and no toxic effects on the yeast strain Y2HGold. An interaction between ScWRKY3 and a reported sugarcane protein ScWRKY4, was confirmed in the nucleus. The gene had the highest expression level in sugarcane stem pith. The transcript of was stable in the smut-resistant hybrid cultivar Yacheng05-179, while it was down-regulated in the smut-susceptible hybrid cultivar ROC22 during inoculation with the smut pathogen () at 0⁻72 h. was remarkably up-regulated by sodium chloride (NaCl), polyethylene glycol (PEG), and plant hormone abscisic acid (ABA), but it was down-regulated by salicylic acid (SA) and methyl jasmonate (MeJA). Moreover, transient overexpression of the gene in indicated a negative regulation during challenges with the fungal pathogen var. or the bacterial pathogen in . The findings of the present study should accelerate future research on the identification and functional characterization of the WRKY family in sugarcane.