A predictive co-expression network identifies novel genes controlling the seed-to-seedling phase transition in Arabidopsis thaliana

SILVA AT; RIBONE PA; CHAN RL; LIGTERINK W; HILHORST HWM

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Lugar: Rockville; Año: 2016

0032-0889

Transition from a quiescent dry seedto an actively growing photoautotrophic seedling is a complex and crucial traitfor plant propagation. This study provides a detailed description of globalgene expression in seven successive developmental stages of seedlingestablishment in Arabidopsis. Using the transcriptome signature from thesedevelopmental stages we obtained a co-expression gene network which highlightsinteractions between known regulators of the seed-to-seedling transition andpredicts the function of uncharacterized genes in seedling establishment. Theco-expressed gene data sets together with transcriptional module indicatesbiological functions related to seedling establishment. Characterization of thehomeodomain leucine zipper I transcription factor ATHB13, which is expressedduring the seed-to-seedling transition, demonstrated that this gene regulatessome of the network nodes and affects late seedling establishment. Knock-out mutantsfor athb13 showed increased primaryroot length as compared with wild type (Col-0) seedlings, suggesting that thistranscription factor is a negative regulator of early root growth, possiblyrepressing cell division and/or cell elongation or the length of time cells elongate.The signal transduction pathways present during the early phases of theseed-to-seedling transition anticipate the control of important events for vigorousseedling, such as root growth. This study demonstrates that a gene co-expressionnetwork together with transcriptional modules can provide insights that are notderived from comparative transcript profiling alone.