Evolution of chloroplast retrograde signaling facilitates green plant adaptation to land

摘要: Chloroplast retrograde signaling networks are vital for chloroplast biogenesis, operation, and signaling, including excess light drought stress signaling. To date, has been considered in the context of land plant adaptation, but not regarding origin evolution cascades linking function to stomatal regulation. We show that key elements process, nucleotide phosphatase (SAL1) 3'-phosphoadenosine-5'-phosphate (PAP) metabolism, evolved streptophyte algae-the algal ancestors plants. discover an early SAL1-PAP regulation based on conserved gene protein structure, function, enzyme activity transit peptides SAL1s species flowering plants, fern Ceratopteris richardii, moss Physcomitrella patens Moreover, we demonstrate PAP regulates closure via secondary messengers ion transport guard cells these diverse lineages. The stomata facilitated gas exchange earliest Our findings suggest conquest by plants was enabled rapid response through deployment ancestral pathway, intersecting with core abscisic acid cells.