Gene network analysis identifies primary regulators of abscisic acid signalling in poplar roots

A study published in PLOS Genetics by David Cohen, Maira De Freitas Pereira, and colleagues characterises how abscisic acid (ABA) — a plant hormone that mediates responses to environmental stress as well as normal growth and development — controls gene expression in the roots of Populus, the tree genus that includes poplars and aspens.

ABA is known to trigger both transcriptional activation and repression, but the upstream regulators responsible, and the precise temporal dynamics of these responses under non-stress conditions, have remained poorly resolved. The authors applied gene network analysis to time-course expression data from Populus roots, identifying candidate transcription factors predicted to act as primary regulators of ABA-dependent transcriptional programmes. The study also characterises the temporal dynamics of these regulatory events, showing that ABA-driven transcriptional changes unfold in a structured sequence rather than as a simultaneous response.

The findings contribute to understanding how a conserved plant signalling pathway — ABA signalling is present across land plants — operates in a woody perennial species of relevance to forestry, biomass research, and studies of tree adaptation to drought and other environmental stressors.