The Arabidopsis type-B cytokinin response regulators ARR1, ARR10 and ARR12 negatively regulate plant responses to drought

To understand the role of the Arabidopsis type-B Response Regulators ARR1, ARR10 and ARR12 in water stress response, we have carried out comparative expression analysis of the arr1,10,12 mutant and WT plants under dehydration and well-watered (control) conditions. Agilent’s whole Arabidopsis Gene Expression Microarray (G2519F-021169, V4, 4x44K) was used. Two-week-old WT and arr1,10,12 mutant plants were transferred from GM plates to soil and grown for 10 additional day. Aerial portions of 24-d-old plants were detached and exposed to dehydration on KimTowel papers for 0 (well-watered, control), 2 and 4 h. Rosette leaves collected in 3 biological repeats from arr1,10,12 and WT plants treated by dehydration for 0, 2 and 4 h were used for microarray and expression analyses. Total RNA was prepared and used for the microarray hybridization. Three independent biological replicates were used for each plant sample.