CHAN Raquel Lia
A matter of quantity: Common features in the drought response of transgenic plants overexpressing HD-Zip I transcription factors
ROMANI FA; RIBONE PA; CAPELLA M; MIGUEL VN; CHAN RL
ELSEVIER IRELAND LTD
Lugar: Amsterdam; Año: 2016
Plantresponses to water deficit involve complex molecular mechanisms in whichtranscription factors have key roles. Previous reports ectopicallyoverexpressed a few members of the homeodomain-leucine zipper I (HD-Zip I)family of transcription factors from different species, and the obtainedtransgenic plants exhibited drought tolerance which extent depended on thelevel of overexpression, triggering diverse molecular and physiologicalpathways. Here we show that most HD-Zip I genes are regulated by drought in thevegetative and/or reproductive stages. Moreover, uncharacterized members ofthis family were expressed as transgenes both in Col-0 and rdr6-12 backgrounds and were able to enhance drought tolerance inhost plants. The extent of such tolerance depended on the expression level ofthe transgene and was significantly higher in transgenic rdr6-12 than in Col-0. Comparative transcriptome analyses of Arabidopsis thaliana plantsoverexpressing HD-Zip I proteins indicated that many members have commontargets. Moreover, the water deficit tolerance exhibited by these plants islikely due to the induction and repression of certain of these common HD-ZipI-regulated genes. However, each HD-Zip I member regulates other pathways,which, in some cases, generate differential and potentially undesirable traitsin addition to drought tolerance. In conclusion, only a few members of thisfamily could become valuable tools to improve drought-tolerance.