A group around Xian JU at CAS QIBEBT in Qingdao found that in microalgae, a complete set of proteins from the canonical ABA and CK sensing and signaling pathways is not essential, but individual components are present, suggesting stepwise recruitment of phytohormone signaling components. Nitrogen deficiency during nitrogen depletion led to activation of the ABA biosynthetic pathway and antagonistic transcription of CK biosynthetic genes, whereas the ABA level increased while the dominant bioactive CK forms decreased.

Yandu LU et al., Plant Journal DOI: 10.1111/tpj.12615