TY - JOUR

T1 - SUMO proteases ULP1c and ULP1d are required for development and osmotic stress responses in Arabidopsis thaliana

AU - Castro, Pedro Humberto Araújo R F

AU - Couto, Daniel

AU - Freitas, Sara

AU - Verde, Nuno

AU - Macho, Alberto P.

AU - Huguet, Stéphanie

AU - Botella, Miguel Angel

AU - Ruiz-Albert, Javier

AU - Tavares, Rui Manuel

AU - Bejarano, Eduardo Rodríguez

AU - Azevedo, Herlânder

PY - 2016

Y1 - 2016

N2 - Sumoylation is an essential post-translational regulator of plant development and the response to environmental stimuli. SUMO conjugation occurs via an E1-E2-E3 cascade, and can be removed by SUMO proteases (ULPs). ULPs are numerous and likely to function as sources of specificity within the pathway, yet most ULPs remain functionally unresolved. In this report we used loss-of-function reverse genetics and transcriptomics to functionally characterize Arabidopsis thaliana ULP1c and ULP1d SUMO proteases. GUS reporter assays implicated ULP1c/d in various developmental stages, and subsequent defects in growth and germination were uncovered using loss-of-function mutants. Microarray analysis evidenced not only a deregulation of genes involved in development, but also in genes controlled by various drought-associated transcriptional regulators. We demonstrated that ulp1c ulp1d displayed diminished in vitro root growth under low water potential and higher stomatal aperture, yet leaf transpirational water loss and whole drought tolerance were not significantly altered. Generation of a triple siz1 ulp1c ulp1d mutant suggests that ULP1c/d and the SUMO E3 ligase SIZ1 may display separate functions in development yet operate epistatically in response to water deficit. We provide experimental evidence that Arabidopsis ULP1c and ULP1d proteases act redundantly as positive regulators of growth, and operate mainly as isopeptidases downstream of SIZ1 in the control of water deficit responses.

AB - Sumoylation is an essential post-translational regulator of plant development and the response to environmental stimuli. SUMO conjugation occurs via an E1-E2-E3 cascade, and can be removed by SUMO proteases (ULPs). ULPs are numerous and likely to function as sources of specificity within the pathway, yet most ULPs remain functionally unresolved. In this report we used loss-of-function reverse genetics and transcriptomics to functionally characterize Arabidopsis thaliana ULP1c and ULP1d SUMO proteases. GUS reporter assays implicated ULP1c/d in various developmental stages, and subsequent defects in growth and germination were uncovered using loss-of-function mutants. Microarray analysis evidenced not only a deregulation of genes involved in development, but also in genes controlled by various drought-associated transcriptional regulators. We demonstrated that ulp1c ulp1d displayed diminished in vitro root growth under low water potential and higher stomatal aperture, yet leaf transpirational water loss and whole drought tolerance were not significantly altered. Generation of a triple siz1 ulp1c ulp1d mutant suggests that ULP1c/d and the SUMO E3 ligase SIZ1 may display separate functions in development yet operate epistatically in response to water deficit. We provide experimental evidence that Arabidopsis ULP1c and ULP1d proteases act redundantly as positive regulators of growth, and operate mainly as isopeptidases downstream of SIZ1 in the control of water deficit responses.

KW - Journal Article

U2 - 10.1007/s11103-016-0500-9

DO - 10.1007/s11103-016-0500-9

M3 - Journal article

C2 - 27325215

VL - 92

SP - 143

EP - 159

JO - Plant Molecular Biology

JF - Plant Molecular Biology

SN - 0167-4412

ER -