JUNGBRUNNEN1 Confers Drought Tolerance Downstream of the HD-Zip I Transcription Factor AtHB13

EBRAHIMIAN-MOTLAGH, SAGHAR; ALLU, ANNAPURNA D.; BALAZADEH, SALMA; THIRUMALAIKUMAR, VENKATESH P.; MUELLER-ROEBER, BERND; RIBONE, PAMELA A.; CHAN, RAQUEL L.

Frontiers in Plant Science

Frontiers

Año: 2017 vol. 8

Lowwater availability is the major environmental factor limiting growth and productivityof plants and crops and is therefore considered of high importance foragriculture affected by climate change. Identifying regulatory components controllingthe response and tolerance to drought stress is thus of major importance. TheNAC transcription factor JUNGBRUNNEN1 (JUB1) from Arabidopsis thaliana extends leaf longevity under non-stress growthconditions, lowers cellular hydrogen peroxide (H2O2)level, and enhances tolerance against heat stress and salinity. Here, we additionallyfind that JUB1 strongly increases tolerance to drought stress in Arabidopsis whenexpressed from both, a constitutive (CaMV 35S)and an abiotic stress-induced (RD29A)promoter. Employing a yeast one-hybrid screen we identified HD-Zip class I transcriptionfactor AtHB13 as an upstream regulator of JUB1.AtHB13 has previously been reported to act as a positive regulator of droughttolerance. AtHB13 and JUB1 thereby establish a joint drought stress controlmodule.