ARR5 and ARR6 Mediate Tissue Specific Cross-talk between Auxin and Cytokinin in Arabidopsis

摘要

Auxin and cytokinin interaction plays an essential role in a wide range of plant growth and developmental processes. The interaction consequence of the two hormones is highly tissue specific. The molecular mechanisms underlying the tissue specificity are largely unknown. Here we show that the cytokinin signaling pathway key components ARR5 and ARR6 respond to auxin with a highly tissue specific and contrasted pattern in Arabidopsis seedlings and calli in the presence of cytokinin. Our results suggest that the two highly homologous but functionally distinct genes, ARR5 and ARR6, play a critical role in mediating tissue specific interaction between auxin and cytokinin.