CYTOKININ HYPERSENSITIVE1 (CKH1) and CKH2 affect to cytokinin responses in tissue culture. Arabidopsis thaliana

Analysis of calli derived from the wild type (Ler), the ckh1 and ckh2 mutants cultured on media in the absence of cytokinin (control), in the presence of low (25 ng/ml kinetin) or high (200 ng/ml kinetin) levels of cytokinin, or in the presence of Trichostatin A (TSA). In these conditions, a constant 2,4-dichlorophenoxyacetic acid (2,4-D) was included as an auxin. Overall design: Hypocotyl segments of the wild type (Ler), ckh1-1 and ckh2-1 mutants were cultured for 3 days on media containing 100 ng/ml 2,4-D in the absence of kinetin or in the presence of low (25 ng/ml) or high (200 ng/ml) kinetin or 100ng/ml TSA, and then collected and rapidly frozen by liquid nitrogen. Total RNA was extracted by using an RNeasy plant kit (Qiagen; USA), and 10 µg of total RNA was used for target preparation by using