The sunflower transcription factor HaWRKY76 confers drought and flood tolerance to Arabidopsis thaliana plants without yield penalty.

RAINERI, JESICA; RIBICHICH, KARINA F; CHAN, RAQUEL L

PLANT CELL REPORTS

SPRINGER

Lugar: Berlin; Año: 2015

0721-7714

Key message Arabidopsis transgenic plants expressingthe sunflower transcription factor HaWRKY76 exhibitincreased yield and tolerance to drought and floodstresses. The genetic construct containing HaWRKY76is proposed as a potential biotechnological tool toimprove crops.Abstract Water deficit and water excess are abiotic stressfactors that seriously affect crops worldwide. To increasethe tolerance to such stresses without causing yield penaltyconstitutes a major goal for biotechnologists. In this survey,we report that HaWRKY76, a divergent sunflowerWRKY transcription factor, is able to confer both dehydrationand submergence tolerance to Arabidopsis transgenicplants without yield penalty. The expression patternof HaWRKY76 was analyzed in plants grown in standardconditions and under different watering regimes indicatinga regulation by water availability. The correspondingcDNA was isolated and cloned under the control of aconstitutive promoter and Arabidopsis plants were transformedwith this construct. These transgenic plants presentedhigher biomass, seed production and sucrose contentthan controls in standard growth conditions. Moreover,they exhibited tolerance to mild drought or flood (completesubmergence/waterlogging) stresses as well as the same orincreased yield, depending on the stress severity and plantdevelopmental stage, compared with controls. Droughttolerance occurred via an ABA-independent mechanismand induction of stomatal closure. Submergence tolerancecan be explained by the carbohydrate (sucrose and starch)preservation achieved through the repression of fermentationpathways. Higher cell membrane stability and chlorenchymamaintenance could be the nexus betweentolerance responses in front of both stresses. Altogether, theobtained results indicated that HaWRKY76 can be apotential biotechnological tool to improve crops yield aswell as drought and flood tolerances